Growing Peppers in Open Ground

Light

Pepper is a light-loving plant. For full growth and fruiting, it needs at least 8–10 hours of direct sunlight per day (Russo, 2012). In the shade, plants stretch, branch poorly, flowering is delayed, and ovaries fall off. A lack of light is especially critical during the formation of buds and fruit set (Pinto et al., 2016). Therefore, the site should be open, without shading from trees, buildings, or tall neighboring crops. Orienting the beds from north to south ensures the most uniform lighting of plants throughout the day.

Wind Protection

Pepper has fragile stems and branches that break easily under gusts of wind, especially when the bushes are laden with fruit (Sundstrom, 1992). Strong wind also increases evaporation from leaves, which can cause stress in plants. Therefore, it is advisable to choose a site protected from prevailing winds—for example, on the south side of buildings, behind a hedge, or using windbreaks of tall crops (sunflower, corn). However, it is important that the protection does not create shade (Kotov and Adritskaya, 2016).

Thermal Regime

Pepper is very sensitive to cold and requires well-warmed areas. Southern and southwestern slopes, which warm up faster in spring and are less susceptible to frost, are best suited (Nonnecke, 1989). In lowlands where cold air stagnates, peppers will suffer from late spring frosts. In regions with cool climates, it is useful to use ridges raised 20–30 cm above the soil level—they warm up faster.

Soil Conditions

Pepper grows best on light, well-drained, fertile soils with a neutral or slightly acidic reaction (pH 6.0–7.0). Ideal soils are loamy or sandy loam with a high content of organic matter (Bosland and Votava, 2012). Heavy clay, acidic, waterlogged, or saline soils are unsuitable for peppers.

Optimal soil parameters for pepper (Pinto et al., 2016):

• pH: 6.0–6.5 (up to 7.0–8.5 acceptable on some soil types)
• Humus: at least 2.5%
• Available phosphorus: at least 150 mg/kg
• Exchangeable potassium: at least 150 mg/kg

On acidic soils (pH below 5.5), peppers suffer from aluminum and manganese toxicity, uptake of calcium and magnesium is impaired, which can lead to blossom-end rot of fruits (Pinto et al., 2016).

Best Predecessors

Peppers cannot be grown in the same place for several years in a row or after other solanaceous crops (tomatoes, potatoes, eggplants, tomatillos)—they share common diseases and pests. The ideal crop rotation involves returning peppers to their original place no earlier than after 3–4 years (Bosland and Votava, 2012; Tarakanov and Mukhin, 2003).

Best predecessors for peppers:

• Legumes (peas, beans, broad beans)—enrich the soil with nitrogen
• Cabbage (all types)
• Cucumbers, zucchini, squash
• Onions and garlic
• Root crops (carrots, beets)
• Green manure crops and perennial grasses

It is not recommended to plant peppers after:

• Tomatoes, potatoes, eggplants (common diseases)
• Tomatillos (also Solanaceae)
• After any crops of the Solanaceae family

It is also advisable to avoid proximity of peppers to cucumbers, as cucumbers can be carriers of cucumber mosaic virus, which also infects peppers (Tarakanov and Mukhin, 2003). Sweet and hot peppers cannot be planted nearby—they cross-pollinate, and sweet peppers become bitter (Sundstrom, 1992).

Why Crop Rotation Is Important

Growing peppers in the same place for more than two consecutive years leads to a loss of yield by 30–50% due to the accumulation of pathogens in the soil, primarily the causative agents of fusarium and verticillium wilt (Pinto et al., 2016). Root rot infections, which remain in the soil for many years, are especially dangerous. Observing crop rotation is the most reliable prevention of many diseases.

Autumn Preparation

Autumn tillage is the key to a good harvest the following year. It includes several stages:

1. Removal of the previous crop and shallow cultivation. Immediately after harvesting the previous crop, the plot is cleared of plant residues. Shallow cultivation (surface loosening) to a depth of 6–8 cm is carried out to provoke weed germination and start the decomposition of organic residues (Tarakanov and Mukhin, 2003). After 2–3 weeks, after weeds appear, deep plowing or digging to a depth of 25–30 cm is carried out. This allows incorporating weeds, improving soil aeration, and promoting moisture accumulation.

2. Application of organic fertilizers. On well-cultivated soils with a humus content of more than 3.5%, mineral fertilizers alone may suffice. On less fertile soils, organic matter is applied under autumn plowing (Pinto et al., 2016):

• Well-rotted manure or humus: 30–50 t/ha (3–5 kg/m²)
• Compost: 40–60 t/ha (4–6 kg/m²)

Important: fresh manure should not be applied under peppers—it causes excessive vegetative growth at the expense of fruiting and can provoke diseases (Sundstrom, 1992). Organic matter is best applied in the fall so that it decomposes by spring.

3. Application of mineral fertilizers (autumn). During autumn preparation, phosphorus and potassium fertilizers are applied, as they are slowly absorbed:

• Superphosphate: 40–60 g/m² (or 300–400 kg/ha)
• Potassium salt or potassium sulfate: 20–30 g/m² (or 150–200 kg/ha)

Nitrogen fertilizers are not applied in autumn—they are leached out and can cause excessive green growth the following spring (Kotov and Adritskaya, 2016).

4. Liming. If the soil pH is below 5.5–6.0, liming is carried out—dolomite flour or hydrated lime is applied. On acidic soils, peppers suffer from calcium and magnesium deficiency, causing blossom-end rot of fruits (Pinto et al., 2016). Liming is carried out 2–3 months before planting, preferably in the fall. The application rate depends on acidity—on average 200–400 g/m². Important: lime should not be applied simultaneously with organic fertilizers—it is better to space them out in time.

Spring Preparation

Spring work begins as soon as the soil is ready—that is, it no longer sticks to tools and crumbles into lumps.

1. Early spring harrowing. To preserve winter moisture, harrowing or loosening of the topsoil is carried out. This closes the capillaries through which water evaporates (Tarakanov and Mukhin, 2003).

2. Application of nitrogen fertilizers. Nitrogen is applied in spring, as it is quickly leached. For peppers, the following is recommended:

• Ammonium nitrate: 20–30 g/m² (or 150–200 kg/ha)
• Complex fertilizers (nitroammophoska) can be used at the rate of 30–40 g/m²

It is important not to overdo nitrogen—excess causes "luxuriant growth," overgrowth of green mass, delayed fruiting, and reduced fruit quality (Sundstrom, 1992; Pinto et al., 2016).

3. Deep cultivation or digging. In spring, cultivation is carried out to a depth of 15–20 cm with simultaneous loosening and removal of emerged weeds. On heavy soils, plowing to 2/3 of the autumn plowing depth is advisable, so as not to bring weed seeds to the surface (Tarakanov and Mukhin, 2003). At the same time, the spring portion of fertilizers is incorporated.

4. Leveling and bed formation. The plot surface is carefully leveled with a rake or cultivator with a leveling bar. This ensures uniform planting depth and facilitates watering. In regions with cool climates or on heavy soils, peppers are grown on ridges 15–20 cm high and 80–100 cm wide. Passages of 40–60 cm are left between ridges. Ridges are best oriented from south to north for uniform lighting.

5. Installation of drip irrigation (if available). If drip irrigation is planned, tapes or pipes are laid before planting, along the future rows. Drip irrigation significantly saves water and allows fertilizers to be applied directly to the root zone.

Optimal Timing

Pepper is a very heat-loving crop. It is planted in open ground only when the threat of return frosts has passed and the soil has warmed to a temperature of at least 15 °C at a depth of 10 cm (Bosland and Votava, 2012). Depending on the region, this may be:

• Southern regions—from mid-April to early May
• Central regions (temperate zone)—from May 25 to June 5–10
• Northern regions—after June 5–10

In the temperate zone of Russia, the traditional period is from May 25 to June 5, when the danger of frost has passed (Tarakanov and Mukhin, 2003). In the Non-Black Earth Zone—in the last five days of May or early June (Nonnecke, 1989). If there is a risk of frost, it is better to postpone planting or provide temporary shelter for the plants.

Temperature Requirements

• Minimum soil temperature: 13–15 °C. At lower temperatures, roots do not function, seedlings do not establish, and may rot (Naik, 2003).
• Optimal daytime air temperature: 20–25 °C
• Night temperature: not below 12–15 °C. At night temperatures below 10 °C, pepper growth stops, and at 5–7 °C it may turn yellow and drop buds (Pinto et al., 2016).

Hardening Off Seedlings Before Transplanting

10–14 days before transplanting, seedlings begin to be hardened off. This is a critically important stage—unhardened plants suffer shock during transplanting, take a long time to recover, and may die.

How hardening is carried out (Pinto et al., 2016; Kotov and Adritskaya, 2016):

1. Temperature reduction. On the first day, seedlings are taken outdoors for 1–2 hours, protected from direct sun. In the following days, the time spent outdoors is gradually increased. 3–4 days before transplanting, seedlings are left outside overnight (if there is no frost). Daytime indoor temperature is reduced by 3–5 °C.

2. Increased light exposure. Gradually accustom plants to direct sunlight, starting with 1–2 hours a day and increasing to a full day.

3. Reduced watering. 7–10 days before transplanting, watering is reduced to increase the concentration of cell sap and resistance to stress. Plants become more hardened, but immediately before transplanting they are watered abundantly (2–3 hours before planting) to facilitate removal from containers.

Important: over-hardening (more than 10–12 days) can lead to slowed growth after transplanting (Kasynkina and Kudin, 2018).

Optimal Schemes for Different Varieties

1. Sweet pepper (bell), medium- and tall-growing varieties:

• Between rows: 70 cm
• Between plants in row: 40–50 cm
• Density: 30–36 thousand plants/ha (approximately 3–4 plants per 1 m²) (Pinto et al., 2016)

2. Sweet pepper, short and early varieties:

• Between rows: 70 cm (or ribbon scheme 40+90 cm)
• Between plants in row: 30–35 cm
• Density: up to 40–45 thousand plants/ha

3. Hot pepper:

• Between rows: 70 cm
• Between plants: 30–40 cm
• Density: up to 40–50 thousand plants/ha (Tarakanov and Mukhin, 2003)

4. Ribbon scheme (for mechanized care):

• Two-row ribbon: (90+50) cm between rows with distances between plants of 25–35 cm. This scheme is often used in intensive technologies (Russo, 2012).

Important: Too dense planting reduces yield, plants shade each other, and the risk of diseases increases. Too sparse—irrational use of area (Sundstrom, 1992).

For tall varieties and hybrids (indeterminate type), the distance between plants is increased to 50–60 cm, for short ones—reduced to 25–30 cm (Bosland and Votava, 2012).

Planting Depth

This is one of the most important points. Pepper, unlike tomato, does not tolerate deep planting—it is planted at the same depth at which it grew in the pot, no deeper than the cotyledon leaves (Pinto et al., 2016). If pepper is buried, the stem may rot, the plant will be sick for a long time and will not produce additional roots, like tomato (Sundstrom, 1992). The optimal depth is up to the cotyledon leaves or the first true leaf.

Step-by-Step Planting Technique

1. Preparing holes. Holes are made in advance or immediately before planting. The depth of the hole is enough to accommodate the root ball and some water (about 20 cm). The distance between holes—according to the chosen scheme.

2. Removing seedlings from the container. To avoid damaging roots, seedlings are removed by slightly squeezing the cell walls and carefully pulling out the plant with the soil ball. Never pull by the stem! If roots are tangled and protrude from the ball, they can be slightly straightened.

3. Watering the holes. 0.5–1.5 liters of warm water (temperature 20–25 °C) is poured into each hole (Pinto et al., 2016). Water is poured before planting or immediately after placing the plant in the hole. This helps roots establish faster.

4. Placing the plant. The plant is placed vertically in the hole, at the depth it grew in the pot. Roots should be spread out and pointing downward. Do not allow roots to bend upward or sideways.

5. Filling. The hole is filled with soil, carefully compacting it around the stem, but not too tightly (so as not to damage roots). A small watering basin is formed around the plant. Do not cover the growing point (apical bud)!

6. Watering after planting. The plant is watered again at the root, using 1–2 liters per plant, so that the soil tightly envelops the roots and there are no voids.

7. Mulching. If film is not used, it is useful to mulch the root zone with peat, humus, or mowed grass with a layer of 3–5 cm. This preserves moisture, prevents crust formation, and suppresses weeds (Bosland and Votava, 2012).

Protection from Sun and Wind

In the first 3–5 days after planting (especially in hot, sunny weather), it is advisable to shade the plants—for example, using non-woven covering material (spunbond, lutrasil) or covering plants with paper caps, cut plastic bottles. This reduces evaporation and helps plants adapt faster. You can transplant seedlings on a cloudy day or in the evening—plants suffer less from sunburn (Pinto et al., 2016).

Watering During the Adaptation Period

In the first week after transplanting, watering should be regular but not excessive. Water daily or every other day, in small amounts, so that the soil is constantly moist, but without water stagnation. It is best to water in the morning, at the root, avoiding water on the leaves. Water temperature should be not lower than 20 °C—cold water causes shock and growth delay (Naik, 2003).

Replacing Lost Plants

If some plants have died or become severely diseased, they can be replaced with healthy seedlings. Studies show that even with the loss of up to 30% of plants and their replacement after 2–3 weeks, the total yield does not decrease (Bracy, 1997; cited in Leskovar and Kahn, 2012). Therefore, do not be afraid to plant new seedlings in place of dead ones.

Protection from Return Frosts

If frost is forecast, plants must be covered. Pepper dies even at temperatures of −0.5…−1 °C (Bosland and Votava, 2012). Use covering material, film, paper caps, or even simply hilling with moist soil (after thawing, unearth). The cover should protect from both wind and cold.

Planting Dates and Site Selection

The most reliable protection is to transplant seedlings at the right time, when the danger of return frosts has passed (Nonnecke, 1989). However, in regions with short summers, it is sometimes necessary to take risks. In such cases, choose warm, well-warmed areas—southern slopes, places near building walls, fences. Southern slopes warm up 1–3 °C faster and are less susceptible to frost (Kotov and Adritskaya, 2016).

Temporary Covers

In case of frost threat, plants can be covered:

• Non-woven covering materials (spunbond, lutrasil, agrotex) with a density of 17–30 g/m². They transmit light and air but protect against frosts down to −2…−3 °C. You can cover plants directly over the leaves, securing the edges with soil. In colder weather, covers with a density of 40–60 g/m² or a double layer are used (Bosland and Votava, 2012).

• Film (polyethylene) — more reliable, but condensation quickly accumulates underneath and temperature rises, so during the day it should be opened or perforated (with holes) film used. Film can protect against frosts down to −5 °C with additional insulation.

• Individual caps — cut plastic bottles, paper caps, cardboard boxes. They are placed over each plant at night and removed in the morning. This is a simple and effective method for a small number of plants.

• Tunnel covers — arches made of wire or plastic pipes, over which film or non-woven material is stretched. They protect plants from cold, wind, and accelerate growth by 1–2 weeks (Russo, 2012). In cold regions, tunnels may remain on the beds throughout the season until stable warmth sets in.

• Hilling — covering the base of the stem with moist soil to a height of 5–8 cm. Moist soil releases heat more slowly, which can save the root collar during short frosts. After thawing, unearth.

It is important to remove covers in the morning as soon as it warms up to avoid overheating. If the cover is not removed, plants under the film may "cook" (Tarakanov and Mukhin, 2003).

Extending the Season in Autumn

In autumn, when the first frosts begin, covering helps extend fruiting for another 2–3 weeks. Tunnels with non-woven material are especially effective (Nonnecke, 1989). In case of severe frosts, you can dig up plants with roots and transplant them into pots for ripening fruits indoors (Balashev and Zeman, 1981).

Shading

In hot regions, it is useful to shade plants for 3–4 hours during the hottest part of the day (usually from 11 a.m. to 3 p.m.). For this, use:

• Non-woven materials with low density (17 g/m²) in white—they scatter light and reduce temperature by 3–5 °C.
• Shade nets (30–50% shading)—stretched over beds on a frame.
• Neighboring with tall crops—for example, windbreaks of sunflower or corn, which provide partial shade during the hottest hours (Tarakanov and Mukhin, 2003).

Watering for Cooling

Watering in hot weather (especially sprinkling) significantly reduces the air temperature around plants. Refreshing irrigation at a rate of 50–80 m³/ha (0.5–0.8 L/m²) is carried out during daytime hours in extreme heat (Naik, 2003). It is important to water with water warmed by the sun to avoid shock from cold water.

Mulching with Light-Colored Materials

In hot regions, it is better to use light mulch—white, silver, or straw. It reflects sunlight, reducing soil temperature by 5–10 °C compared to black film (Bosland and Votava, 2012). In southern conditions, black film can overheat roots, inhibiting plants.

Windbreaks and Shelterbelts

• Live hedges of tall plants (sunflower, corn, sorghum) planted on the windward side of the bed. Windbreaks are planted 2–3 weeks before transplanting seedlings so they have time to grow (Russo, 2012).
• Fences, buildings, screens—walls of houses, sheds, or special windbreaks made of pickets or netting. It is important that the protection does not create shade (Kotov and Adritskaya, 2016).

Staking Plants

Tall pepper varieties must be staked to stakes or trellises. This protects stems from breaking even in strong winds. Even for determinate (short) varieties, staking helps support heavy fruits and prevent lodging (Russo, 2012). Staking is carried out 5–7 days after transplanting, making a loose loop (at least 3–4 cm in diameter) around the stem (Pinto et al., 2016).

Mulching

Mulch is one of the most effective tools for managing conditions (Bosland and Votava, 2012). It performs several functions:

Organic mulch (humus, compost, mowed grass, straw, sawdust):

• Retains moisture, reducing evaporation by 30–50%
• Softens soil temperature fluctuations
• Suppresses weed growth
• Gradually decomposes, enriching soil with organic matter
• Disadvantage: may delay soil warming in spring, attract slugs (Kotov and Adritskaya, 2016)

Inorganic mulch (polyethylene film):

• Black film — most common. Raises soil temperature by 2–4 °C, effectively suppresses weeds, retains moisture (Bosland and Votava, 2012). In cool regions, this gives a significant gain in growth and yield.
• Reflective film (silver, white, aluminum)—reflects light, cools the soil, and repels aphids and other pests (Russo, 2012). In hot regions, it is preferable to black.
• Red or yellow film — can influence growth and development of peppers (different light spectra affect the plant). It has been experimentally proven that red film promotes more vigorous growth compared to black or yellow (Decoteau et al., 1990; cited in Russo, 2012).

Mulch application timing: Organic mulch is applied after the soil has warmed, when plants are well established and beginning to grow actively. Black film is laid before planting (or at planting) to warm the soil.

Watering as a Microclimate Regulator

Watering not only provides moisture but also regulates temperature and air humidity (Naik, 2003). Recommendations:

• In heat, daytime watering (refreshing) reduces temperature by 2–4 °C.
• In cool weather, water in the morning so that plants have time to dry by evening (reducing the risk of fungal diseases).
• In cold weather, water with warm water (20–25 °C) to avoid cooling roots.
• Drip irrigation—the most effective method: water goes directly to the root zone, leaves remain dry, evaporation is minimal (Naik, 2003).

Raised Beds

In cold regions, peppers are recommended to be planted on high (20–30 cm) ridges. They warm up faster in spring, water does not stagnate, roots breathe better (Russo, 2012). In very cold regions, ridges are oriented from north to south (for maximum warming) or from east to west (for better lighting)—this depends on specific conditions (Kotov and Adritskaya, 2016).

Warm Beds

In regions with short and cool summers, you can make warm beds—with a layer of fresh manure or plant residues at the base, which release heat during decomposition (Balashev and Zeman, 1981). Such a bed is prepared in autumn or early spring. Soil temperature on a warm bed is 3–5 °C higher than in open ground, allowing peppers to be planted 1–2 weeks earlier.

Ventilation

When using film covers, ventilation is very important, especially on sunny days. Otherwise, the temperature under the film can rise above 40 °C, leading to the death of flowers and ovaries (Tarakanov and Mukhin, 2003). For this, the film is opened from the ends or sides, and "windows" are made in the non-woven material.

Periods of Critical Moisture Need

The greatest need for water in pepper occurs in three key periods (Naik, 2003; Sundstrom, 1992):

1. After transplanting seedlings (adaptation period)—the root system is still weak, and evaporation through leaves is already high. In the first week after planting, water daily or every other day in small amounts.

2. Budding and flowering period—lack of moisture during this period leads to mass dropping of flowers and ovaries. This is a critical period when soil moisture should be maintained at the upper optimum (75–80% field capacity).

3. Fruit filling period—for the formation of large, juicy fruits, a steady supply of water is required. Lack of moisture during this period leads to the formation of small, deformed fruits (Bosland and Votava, 2012).

Watering Frequency

Watering frequency depends on weather, soil type, and plant age (Naik, 2003):

• In hot weather (above 25–28 °C): water every 2–4 days.
• In cool weather (18–22 °C): water once every 5–7 days.
• In rainy weather: reduce or stop watering if rainfall is sufficient.
• On light sandy soils: water more often (every 2–3 days), but in smaller amounts.
• On heavy clay soils: water less often (once every 5–7 days), but more abundantly.

In tropical and subtropical regions (south India, Mediterranean), 8–12 waterings per season are recommended (Naik, 2003). In the Non-Black Earth Zone, 3–5 waterings per season are usually sufficient if there is regular rain (Kotov and Adritskaya, 2016).

Signs That Watering Is Needed

The best way to determine if watering is needed is to check the soil at a depth of 5–10 cm (at the level of the main root mass) (Pinto et al., 2016):

• Soil dry, crumbles in hand—urgent watering needed.
• Soil moist but does not stick to fingers—water in 1–2 days.
• Soil wet, sticks to hands—watering not needed.
• Soil excessively wet, water oozing—stop watering and improve drainage.

Observe the condition of the plants: if leaves lose turgor and wilt in hot weather before 3–4 p.m.—the plant signals a lack of moisture. If wilting persists until morning—this is already a serious signal.

Drip Irrigation

Drip irrigation is the most effective method for peppers (Naik, 2003; Russo, 2012). Its advantages:

• Water savings—water consumption is reduced by 30–50% compared to surface irrigation.
• Minimal evaporation—water goes directly to the root zone.
• Leaves remain dry—reduces the risk of fungal diseases (powdery mildew, late blight, bacterial spot).
• Uniform moisture—roots receive moisture constantly, without fluctuations (Naik, 2003).
• Fertigation capability—through drip lines, fertilizers can be applied directly to the root.
• Fewer weeds—soil between rows remains dry, weeds do not germinate.

Disadvantage: higher initial cost of equipment (drip tape, fittings, filters, pressure regulators). For a small garden, simple systems can be used—drip tubes with holes or even plastic bottles with punctured holes buried next to the plant.

Drip irrigation rates: 2–4 liters of water per plant per watering (depending on weather), frequency—2–4 days in heat and 5–7 days in cool weather (Naik, 2003).

Sprinkler Irrigation (Overhead Watering)

Sprinkler irrigation is a traditional and accessible method (Naik, 2003). Advantages:

• Cools plants and air in heat (refreshing irrigation).
• Moistens leaves, which helps in controlling some pests (e.g., spider mites).
• Does not require complex equipment.

Disadvantages:

• Large water losses to evaporation—up to 30–40% of water evaporates without reaching roots.
• Wet leaves—create favorable conditions for fungal diseases (late blight, powdery mildew, alternaria).
• Soil compaction—water drops break down the structure of the top layer, forming a crust.
• Uneven watering—in strong winds, spraying is uneven.

Refreshing irrigation in heat is watering with small amounts (50–80 m³/ha, or 0.5–0.8 L/m²) during daytime to cool plants. They do not replace the main watering but complement it (Naik, 2003; Tarakanov and Mukhin, 2003).

Surface Irrigation (Furrow Irrigation)

A traditional method common in southern regions and for large-scale cultivation (Naik, 2003). Water is supplied through furrows between rows. Advantages: simplicity, low equipment cost. Disadvantages: large water losses, uneven wetting, possible water stagnation, high risk of fungal diseases.

For peppers, surface irrigation is used less frequently due to the plant's sensitivity to overwatering. Water should be supplied to the furrows but not touch the plant stems (Naik, 2003).

Cool Regions (North, Siberia, Non-Black Earth Zone)

• Main emphasis—watering in the morning so that plants have time to dry by evening.
• Water must be warmed.
• Reduce watering in rainy, cold weather to avoid creating conditions for fungal diseases.
• Use drip irrigation to avoid wetting leaves (Kotov and Adritskaya, 2016).

Temperate Regions (Middle Zone)

• Optimal regime: watering 2–3 times a week, rate 3–4 L per plant.
• During extreme heat (above 28 °C), additional watering (including refreshing) is carried out.
• Towards the end of the season (2–3 weeks before the last harvest), watering is reduced or stopped—this promotes better fruit ripening and improves their color (Sundstrom, 1992; Naik, 2003).

Hot and Arid Regions (South, Steppe, Subtropics)

• Watering frequency—every 2–3 days, rate—4–5 L per plant.
• Drip irrigation or furrow irrigation is mandatory to minimize evaporation.
• Periodic refreshing sprinkler irrigation during daytime.
• Maintaining moisture at 80% field capacity (Naik, 2003).

Irrigated Areas with Saline Soils

• With high water mineralization (EC > 1.5–2.0 dS/m), more frequent watering is required to leach salts from the root zone (Naik, 2003).
• Using drip irrigation in such conditions helps save water and better control salinization.
• In some cases, alternating irrigation with brackish and fresh water is used.

Overwatering (Excess Water)

• Leaves become pale green or yellow (chlorosis)—especially lower ones (Naik, 2003).
• Leaves wilt (may droop) even when soil is moist.
• Stems become soft, watery. Stem base darkens (root collar infection).
• Mold or moss on soil surface.
• Slowed growth, cessation of fruiting.
• Flower and ovary drop even when soil is still wet (Bosland and Votava, 2012).

With such signs, reduce watering, loosen the soil to improve aeration, and if necessary, make drainage ditches (Naik, 2003).

Lack of Moisture (Drying Out)

• Leaves lose turgor, droop (wilt) during the hot part of the day—first stage of moisture deficit (Pinto et al., 2016).
• Lower leaves turn yellow and dry up.
• Flowers and ovaries drop massively.
• Fruits become smaller, less juicy, may become bitter.
• Soil dry, crumbles in hand.
• Cracks on fruits (sharp drying of soil followed by watering).

At the first signs of moisture deficit, water. If wilting persists until morning—urgent watering.

Nitrogen (N)

Nitrogen is the main element for green mass growth. It is involved in the formation of proteins, chlorophyll, and enzymes. Nitrogen nutrition is especially important in the initial growth period, before flowering, and at the beginning of fruiting (Pinto et al., 2016).

Signs of nitrogen deficiency:

• Plants are small, weak, with thin stems (Pinto et al., 2016).
• Leaves become light green, then yellow, starting from the bottom.
• Growth slows, leaves become smaller.
• Flowering is weak, few fruits, they are small.
• Root system is underdeveloped (Nonnecke, 1989).

Signs of excess nitrogen:

• Plants are vigorous, with large dark green leaves ("luxuriant growth").
• Flowering is delayed, few fruits.
• Shoots become soft, "watery," easily break (Sundstrom, 1992).
• Reduced resistance to diseases and frost.
• Fruits may suffer from blossom-end rot due to imbalance with calcium.

Excess nitrogen is especially harmful—it delays fruit ripening, impairs taste (reduces sugar content) and storage ability (Pinto et al., 2016; Tarakanov and Mukhin, 2003).

Phosphorus (P)

Phosphorus is responsible for root development, flowering, fruit set and ripening. It also increases plant resistance to diseases and low temperatures (Pinto et al., 2016; Nonnecke, 1989). Pepper absorbs phosphorus poorly from soil, especially in cold weather (below 15 °C), so it is important to ensure its availability.

Signs of phosphorus deficiency:

• Leaves become smaller, dark green or bluish-green ("bluish" tint).
• Young leaves are small, grow upward at an acute angle to the stem (Tarakanov and Mukhin, 2003).
• Lower leaves may take on a purple tint (especially on petioles and veins).
• Flowering and fruiting are delayed.
• Root system is weak, root growth is slowed.
• Fruits are small, uneven, may be deformed (Pinto et al., 2016).

Phosphorus is especially important in the initial growth period—it stimulates root development and accelerates entry into fruiting (Kotov and Adritskaya, 2016).

Potassium (K)

Potassium is responsible for fruit quality—their size, color, taste, storage, and transportability. It also increases plant resistance to drought, diseases, and temperature fluctuations (Pinto et al., 2016; Sundstrom, 1992). Potassium is especially important during fruit formation and ripening.

Signs of potassium deficiency:

• Leaf edges turn yellow, then brown and dry ("marginal burn") (Pinto et al., 2016).
• Leaves become wrinkled, curl downward.
• Lower leaves turn yellow and fall off.
• Fruits become smaller, skin becomes thin, flesh loose.
• Fruit storage ability decreases.
• Plant becomes more susceptible to diseases (Nonnecke, 1989).

Potassium is especially important for sweet peppers—with its deficiency, fruits lose sweetness, become watery, and store poorly (Sundstrom, 1992).

Calcium (Ca)

Calcium strengthens cell walls and participates in the transport of other elements. It is especially important for fruit formation and preventing blossom-end rot (Pinto et al., 2016; Nonnecke, 1989). Calcium moves poorly in the plant, so its deficiency manifests on young tissues and fruits.

Signs of calcium deficiency:

• Young leaves are small, deformed, with edges curled downward (Pinto et al., 2016).
• Apical growing point dies or is damaged.
• Dark, sunken spots appear on fruits (blossom-end rot)—especially in hot, dry weather (Bosland and Votava, 2012).
• Roots are weak, root growth stops.
• Flowers drop without setting fruit (Tarakanov and Mukhin, 2003).

Blossom-end rot of fruits is the most characteristic sign of calcium deficiency. It appears as watery spots on the fruit tip (opposite the stalk), which then darken and become dry. The first fruits are most often affected (Pinto et al., 2016).

Magnesium (Mg)

Magnesium is the central element of the chlorophyll molecule. It is involved in photosynthesis and protein metabolism. Pepper is especially sensitive to magnesium deficiency, which often occurs on light, acidic soils (Pinto et al., 2016; Nonnecke, 1989).

Signs of magnesium deficiency:

• Chlorosis (yellowing) between veins on lower and middle leaves (veins remain green) (Pinto et al., 2016).
• Leaves become brittle, may curl.
• Fruits become smaller, their number decreases.
• Root system develops poorly (Nonnecke, 1989).

On acidic soils and with excess potassium, magnesium absorption is worse (Pinto et al., 2016).

Organic Fertilizers

Pepper responds well to organic fertilizers, especially humus and well-rotted compost (Pinto et al., 2016; Tarakanov and Mukhin, 2003).

Humus or compost: Applied in autumn or spring during digging: 3–6 kg/m² (30–60 t/ha). It improves soil structure, increases moisture capacity, enriches with humus and trace elements (Pinto et al., 2016).

Manure: Fresh manure cannot be applied under peppers! It causes excessive green growth at the expense of fruiting, can burn roots, and promote diseases (Sundstrom, 1992). Manure is applied only well-rotted, preferably in autumn under the preceding crop (Pinto et al., 2016).

Wood ash: A valuable source of potassium, calcium, magnesium, and trace elements. Applied 100–200 g/m² during digging or in holes during planting (30–40 g per hole). Ash also reduces soil acidity (Kotov and Adritskaya, 2016).

Poultry manure: A strong organic fertilizer. Used only in rotted form or as a liquid infusion (1:15–20). In dry form or high concentration, it can burn roots (Pinto et al., 2016).

Mineral Fertilizers

Nitrogen: Ammonium nitrate (34% N), urea (46% N), ammonium sulfate (21% N + 24% S). Applied in spring, in split doses (Tarakanov and Mukhin, 2003).

Phosphorus: Single superphosphate (19% P₂O₅), double superphosphate (42–46% P₂O₅). Applied in autumn or spring during primary tillage, as phosphorus moves slowly in the soil (Pinto et al., 2016).

Potassium: Potassium sulfate (50% K₂O)—preferable, as it contains no chlorine; potassium salt (30–40% K₂O), potassium chloride (60% K₂O)—contains chlorine, which can inhibit growth. Potassium fertilizers are applied in autumn (part) and spring (in topdressings) (Pinto et al., 2016; Sundstrom, 1992).

Complex: Nitroammophoska (NPK 16:16:16), diammophoska (10:26:26), azofoska. Convenient for pre-sowing application.

Micronutrients: Use complex microfertilizers (e.g., "Micromix," "Tsitovit," "Aquamix") or individual elements (boric acid, zinc sulfate, manganese sulfate, ferrous sulfate). Applied both to soil (in small doses) and as foliar sprays (Pinto et al., 2016).

Basic Application (Before Planting)

The entire basic dose of phosphorus and potassium (2/3 of the dose), as well as organic fertilizers, are applied in autumn during digging. Nitrogen fertilizers are applied in spring because they are quickly leached (Pinto et al., 2016; Tarakanov and Mukhin, 2003).

Recommended doses per 1 m²: (approximate, adjust according to soil analysis)

• Organic: 3–6 kg of humus or compost (autumn).
• Nitrogen (N): 20–30 g of ammonium nitrate (spring) (Pinto et al., 2016).
• Phosphorus (P₂O₅): 30–60 g of single superphosphate (autumn or spring).
• Potassium (K₂O): 20–30 g of potassium sulfate (autumn and in topdressings).

On well-cultivated soils (humus > 3.5%), you can limit yourself to mineral fertilizers and apply them in spring. On poor soils—be sure to add organic matter (Pinto et al., 2016).

Option of starter fertilizer in the hole: At planting, you can add 10–15 g of superphosphate and 5–10 g of potassium sulfate to the hole, mixing well with soil so that roots do not touch the fertilizers (Kotov and Adritskaya, 2016).

Fertilization No. 1 — 10–14 days after transplanting

After the seedlings have established and begun to grow actively (usually 10–14 days after planting), the first feeding is carried out. It stimulates plant growth and development (Pinto et al., 2016).

Composition (per 1 m² or per 10 L of water for watering 2–3 m²):

• Nitrogen: 10–15 g (ammonium nitrate)
• Phosphorus: 15–20 g (superphosphate)
• Potassium: 10–15 g (potassium sulfate)

You can use a complex fertilizer (e.g., nitroammophoska 20–30 g/m²). Water at the root after the main watering to avoid burning roots.

Fertilization No. 2 — during budding and flowering

This feeding promotes abundant flowering and fruit set. Nitrogen should not dominate during this period—otherwise there will be "luxuriant growth" at the expense of fruiting (Sundstrom, 1992).

Composition (per 10 L of water):

• Ammonium nitrate: 10–15 g
• Superphosphate: 20–30 g
• Potassium sulfate: 15–20 g
• e 2–3 L of solution per 1 m² (Pinto et al., 2016).

You can also apply foliar boron (0.1% boric acid solution) and micronutrients to improve fruit set (Pinto et al., 2016).

Fertilization No. 3 — during fruit growth

During mass fruit filling and fruiting, the need for potassium and phosphorus increases, while nitrogen decreases (Pinto et al., 2016; Tarakanov and Mukhin, 2003).

Composition (per 10 L of water):

• Ammonium nitrate: 5–10 g (or skip if plants are well developed)
• Superphosphate: 20–30 g
• Potassium sulfate: 20–25 g
• plication rate—2–3 L per 1 m² (Pinto et al., 2016).

Additional Fertilizations

With prolonged fruiting, 1–2 additional feedings can be carried out with intervals of 10–14 days, alternating compositions (Kotov and Adritskaya, 2016). At the end of the season, fertilizations are stopped.

Root Feeding (watering under the root)

The most common method. Fertilizers are dissolved in water and watered at the root, preferably after the main watering to avoid burning roots. Application rate—2–3 L/m² or 10–15 L per 5–8 plants (Pinto et al., 2016).

Foliar Feeding (on leaves)

A very effective method for quickly eliminating micronutrient and some macronutrient deficiencies. The solution is sprayed on the leaves. Leaves absorb nutrients well, especially from the underside (Pinto et al., 2016).

Advantages:

• Fast action (effect in 1–2 days).
• High absorption (up to 80–90% of the element).
• Can be combined with pest and disease treatments.
• Especially effective for micronutrients (iron, boron, zinc, manganese) (Pinto et al., 2016).

Disadvantages:

• Short action (requires repeated treatments).
• High concentration can burn leaves.
• Conduct only in cloudy weather or in the morning/evening.

Recommendations for foliar feeding:

• Micronutrients: complex preparations or 0.05–0.1% solutions of individual elements (Pinto et al., 2016).
• Boric acid: 0.1% (1 g/L), especially during flowering.
• Magnesium sulfate: 0.2–0.5% (2–5 g/L).
• Urea: 0.5% (5 g/L)—for rapid nitrogen replenishment.
• Solution temperature: 20–25 °C.
• Application rate: 300–400 L/ha (30–40 L per 100 m²) (Pinto et al., 2016).

Fertigation (through drip irrigation)

With drip irrigation, fertilizers can be applied directly in the irrigation water. This is the most effective method for root feeding (Naik, 2003). Advantages: precise dosing, uniform distribution in the root zone, minimal losses, possibility of frequent feeding in small doses.

Recommendations for fertigation:

• Use only well-soluble fertilizers (potassium nitrate, calcium nitrate, monoammonium phosphate, complex fertilizers for fertigation).
• Solution concentration not more than 1–2% (10–20 g/L) (Naik, 2003).
• Apply fertilizers at the beginning of irrigation (or in the middle) to flush the solution from the drippers and avoid clogging (Naik, 2003).

Determinate Varieties (short, standard, bushy)

• Bush height: 30–80 cm.
• Growth is limited: the main stem ends in a flower cluster.
• Fruiting is concentrated, yield is concentrated on 3–5 tiers.
• Do not require suckering. Shaping is minimal—removal of the "crown" flower, sometimes thinning.
• Examples: "Lastochka," "Gift of Moldova," "Winnie-the-Pooh," "Bulgarian 79," "Kupets" (Pinto et al., 2016; Kotov and Adritskaya, 2016).

Indeterminate and Semi-Determinate Varieties (tall)

• Bush height: over 100–150 cm (in open ground usually up to 120–150 cm).
• Growth is unlimited: the main stem continues to grow and forms new flower clusters.
• Fruiting is extended, yield is formed throughout the season.
• Require shaping—suckering, staking, sometimes topping.
• Examples: "California Wonder," "Nezhnost," "Buratino F1," "Zdorovye," "Alyonushka" (Pinto et al., 2016).

In open ground, determinate and semi-determinate varieties are usually grown, as they are more resilient and do not require complex care (Sundstrom, 1992). However, they also have their own shaping nuances.

1. Removal of the "Crown" (First) Flower

This is the most important and mandatory technique for all pepper varieties. The first flower that appears in the first fork (on the main stem) is called the "crown" flower (Pinto et al., 2016; Tarakanov and Mukhin, 2003).

Why remove: If you leave this flower, it will produce a fruit, but it will "take" strength from the plant, inhibiting the growth and development of other shoots. As a result, the bush will be weak, with poorly developed side shoots and few fruits. Removing the crown flower stimulates the growth of side shoots, making the bush more vigorous and productive (Bosland and Votava, 2012; Pinto et al., 2016).

When and how: The crown flower is removed as soon as it appears (usually 10–14 days after transplanting seedlings). It is simply pinched or cut off. Sometimes, together with the flower, the buds of the first tier are also removed. This simple procedure increases yield by 20–30% (Pinto et al., 2016).

2. Suckering (Removing Side Shoots)

Suckers are side shoots that grow from the leaf axils on the main stem (Sundstrom, 1992). Unlike tomatoes, suckering is not mandatory for peppers. It is used only for certain types of varieties and for specific purposes.

When suckering is needed:

• For tall (indeterminate) varieties—to form a bush in 2–3 stems and redirect nutrition to fruits.
• In regions with short summers—to accelerate ripening, leaving only 3–5 large ovaries on the plant.
• In dense planting—to improve ventilation and lighting (Russo, 2012).

How to sucker:

• Remove all side shoots (suckers) below the first fork (up to the first branching). This forms a "standard" (bare stem) 10–15 cm high (Pinto et al., 2016).
• Above the first fork, leave 2–3 of the strongest shoots (usually those coming from the fork). These will be the basis of the bush. Remove the remaining suckers (Kotov and Adritskaya, 2016).
• In the future, remove excess suckers, especially those growing inside the bush or thickening it. Usually, 3–4 fruit branches are left on each skeletal shoot.

When not to sucker:

• For short determinate varieties (they limit growth themselves).
• When growing for an early harvest (suckers give additional yield, albeit smaller).
• With sufficient space and good lighting (Sundstrom, 1992).

Important: Suckers are removed when they are still small (1–2 cm) to avoid injuring the plant. They are removed manually, by pinching, or cutting with a sharp knife, leaving no stumps (Pinto et al., 2016).

3. Removing Lower Leaves

Lower leaves, especially those touching the ground or heavily shading the soil, are removed. They can be a source of diseases and pests and also consume nutrients (Nonnecke, 1989; Pinto et al., 2016).

Why remove:

• Improves ventilation at the base of the bush.
• Reduces the risk of fungal diseases (late blight, alternaria).
• Removes "excess ballast," redirecting nutrition to fruits.
• Facilitates watering and care.

How to remove: Remove leaves located below the first fork (lower 3–5 leaves), as well as those that are yellowing, old, or damaged. Remove them gradually, not all at once, so as not to weaken the plant (Pinto et al., 2016). It is better to remove in the morning in dry weather so that wounds have time to heal.

4. Topping (Pinching) the Tips

Topping is the removal of the apical growing point on the main stem and skeletal shoots (Tarakanov and Mukhin, 2003). This technique is used to limit plant growth and direct nutrition to already formed ovaries.

When to top:

• 3–4 weeks before the end of the season (expected frosts)—to accelerate ripening of already set fruits. Leave 3–4 leaves above the top ovary, remove the rest (Pinto et al., 2016).
• For tall varieties in regions with short summers—when the bush has reached the desired height (usually 100–120 cm) and has laid enough fruit buds (Nonnecke, 1989).
• For autumn cultivation (in warm regions)—to form a compact bush for autumn fruiting (Russo, 2012).

How to top: Using a sharp knife or pruners, remove the shoot tip, leaving 2–3 leaves above the top ovary. If there are no fruits on the shoot yet, topping should not be done—it will lead to a reduction in yield (Pinto et al., 2016).

5. Removing Excess Ovaries and Crop Load Regulation

In peppers, especially in open ground, many fruits set, but the plant cannot "feed" them all to large sizes. To obtain large, high-quality fruits, part of the ovaries must be removed (Pinto et al., 2016; Nonnecke, 1989).

How to regulate:

• On determinate varieties, leave 10–15 ovaries per bush (for large-fruited varieties—5–8).
• On indeterminate—up to 20–25 ovaries.
• Remove small, underdeveloped, deformed ovaries, as well as those growing deep in the bush.
• First remove fruits that touch the ground—they are more often affected by diseases (Pinto et al., 2016).

Features for different types:

• For very large fruits (for exhibitions, sale)—leave 3–5 of the strongest ovaries.
• For canning (small fruits)—regulation is not mandatory.
• For hot pepper—leave more ovaries (they are smaller and do not require as much nutrition) (Pinto et al., 2016; Sundstrom, 1992).

6. Staking Plants

Staking is important for tall and even medium-growing varieties, especially in open ground, where wind and fruit weight can easily break fragile stems (Russo, 2012).

When to stake: 5–10 days after transplanting, when plants have established. Staking is carried out as plants grow.

Staking methods (Sundstrom, 1992; Tarakanov and Mukhin, 2003):

1. To stakes—the simplest method. A stake 60–80 cm high (for short) or up to 1.5 m (for tall) is driven next to each plant. The stem is tied to the stake in several places as it grows. The loop should be loose (at least 3–4 cm in diameter) so as not to constrict the stem.

2. On a trellis—a more complex but very effective method for tall varieties. Wire or rope is stretched along the row at a height of 1–1.2 m. Each stem is tied to it, or the plant is formed into 2–3 stems and tied to the trellis.

3. To a common row (row staking)—rope or twine is stretched between rows, to which plants are tied.

4. With stakes and twine (for tall varieties)—stakes are driven at the ends of the row, 2–3 rows of wire or twine are stretched, to which stems are tied.

Materials for staking: Cotton twine, soft coated wire, special plastic clips. Do not use thin fishing line or rope that can cut the stem (Pinto et al., 2016).

For Early Harvest (in Cold Regions)

• Remove the crown flower (mandatory) (Pinto et al., 2016).
• Leave 2–3 of the strongest shoots, remove the rest of the suckers.
• Leave 3–5 ovaries on each shoot, remove the rest.
• Regularly remove new flowers and ovaries so that all the plant's energy goes to already formed fruits (Russo, 2012).
• 3–4 weeks before frost, top the shoots.

For Maximum Yield (in Warm Regions)

• Remove the crown flower (Pinto et al., 2016).
• Leave 3–4 shoots (minimal suckering).
• Remove only old, yellowed leaves and suckers that shade the bush.
• Stake all shoots.
• Do not regulate ovaries (or remove only deformed ones).

For Large Fruits

• Remove the crown flower.
• Leave 2–3 shoots, remove the rest (suckering) (Pinto et al., 2016).
• Leave 3–4 of the strongest ovaries on each shoot, remove the rest.
• Regularly remove new flowers so the plant does not waste energy on them.
• Stake all shoots so they do not break under the weight of large fruits.

For Hot Pepper

• Crown flower removal is not mandatory (can be done, but less effect) (Pinto et al., 2016).
• Suckering minimal or not required.
• Shape the bush naturally, removing only old, diseased, or damaged shoots and leaves.
• Leave more ovaries (they are smaller and do not require intensive nutrition).
• Hot pepper in open ground is generally less demanding of shaping (Sundstrom, 1992).

Temperature

This is the main factor affecting pepper pollination. Pepper is very sensitive to extreme temperatures during flowering (Pinto et al., 2016; Bosland and Votava, 2012):

• Optimal temperature for pollination: 20–25 °C.
• At temperatures below 15 °C: pollen does not germinate, pollination does not occur (Nonnecke, 1989). Flowers may remain on the plant, but fruits do not set.
• At temperatures above 30–32 °C: pollen becomes sterile (non-viable). Even if pollination occurs, fruits may be deformed or seedless (Pinto et al., 2016).
• At temperatures above 35 °C: flowers drop en masse before pollination (Sundstrom, 1992).
• Sharp temperature fluctuations (hot days, cold nights) also negatively affect pollination (Pinto et al., 2016).

In hot weather (above 30 °C), pollen becomes sterile, and even in the presence of insects, pollination does not occur. This is one of the main reasons for flower and ovary drop in summer in southern regions (Bosland and Votava, 2012).

Air Humidity

The optimal relative humidity for pepper pollination is 60–70% (Pinto et al., 2016):

• At humidity below 50%: pollen dries out, loses viability, the stigma dries out, pollination is hindered (Nonnecke, 1989).
• At humidity above 80–90%: pollen sticks together, does not fall out of the anthers, pollination is also disrupted (Pinto et al., 2016).
• High humidity also promotes fungal diseases that can affect flowers.

Wind

Wind helps self-pollination by shaking plants and promoting pollen release (Pinto et al., 2016). However, strong winds can damage flowers and knock them off. In open ground, moderate wind is usually beneficial for pepper pollination.

Insect Pollinators

Although peppers are mostly self-pollinating, insects (especially bees, bumblebees, thrips, ants) can significantly improve pollination, especially in hot and dry weather when pollen does not fall out as easily (Pinto et al., 2016; Nonnecke, 1989). They transfer pollen from flower to flower, increasing the fruit set percentage.

Studies show that with insect participation, fruit set is higher by 10–20%, and fruits grow larger and more uniform (Pinto et al., 2016). This is especially noticeable in open ground, where there are enough insects, unlike greenhouses where pollination often requires artificial intervention (Nonnecke, 1989).

Variety

Different varieties respond differently to pollination conditions. In some varieties, the stigma is located below or at the same level as the anthers—they self-pollinate better. In others, the stigma protrudes higher—they depend more on insects and cross-pollination (Pinto et al., 2016). In open ground, varieties with high self-pollination capacity are usually chosen for stable yields.

Parthenocarpic Varieties (Special Case)

There are parthenocarpic pepper varieties that produce fruits without fertilization (seedless). They do not require pollination at all. Such varieties are especially convenient in greenhouses, but they can also be used in open ground (Pinto et al., 2016; Nonnecke, 1989). Parthenocarpic fruits often have thinner walls and a less pronounced taste, but they are guaranteed to set even in unfavorable weather.

1. Attracting Insect Pollinators

Insects are your best helpers in pepper pollination, especially in hot weather when self-pollination is difficult (Pinto et al., 2016; Nonnecke, 1989).

How to attract insects:

• Planting honey plants next to the pepper bed and between them: phacelia, buckwheat, sunflower, coriander, dill, flowering herbs. They attract bees and bumblebees (Pinto et al., 2016).
• Maintain natural vegetation around the plot—many wild bees and bumblebees live near fields.
• Do not use insecticides during flowering, especially in the morning when insects are most active. If treatment is necessary, conduct it in the evening when insects are no longer flying (Nonnecke, 1989).
• Use biological products instead of chemicals to avoid killing beneficial insects (Pinto et al., 2016).

In open ground, there are usually enough insects to ensure good pollination. But in hot, dry, or windy weather, their activity decreases, and additional help may be needed.

2. Artificial (Manual) Pollination

If insects are insufficient or weather is unfavorable, you can help plants yourself (Pinto et al., 2016; Nonnecke, 1989).

Manual pollination methods:

Shaking plants. The simplest method. Gently shake the flowering branches or the whole bush. Pollen falls out of the anthers and lands on the stigma. Shake in dry, warm weather when flowers are open (usually from 9 to 11 a.m.) (Pinto et al., 2016). Shaking is especially effective in calm weather.

Tapping on flowers. Light tapping with a finger or stick on flowers and branches helps pollen shed.

Brush or cotton swab. Gently run a soft brush or cotton swab over the inside of the flower to transfer pollen from the stamens to the stigma. This method is more labor-intensive but very effective for individual bushes (Nonnecke, 1989).

Fan (in hot weather). You can use a small fan to create air movement around plants. This promotes pollen release and transfer (Pinto et al., 2016).

When to conduct: The best time for artificial pollination is morning (from 9 to 11 a.m.), when flowers are fully open and pollen is most viable (Pinto et al., 2016). In hot weather (above 28–30 °C), pollen may be sterile—in this case, artificial pollination may not help.

3. Spraying with Growth Regulators

To stimulate fruit set, growth regulators can be used, especially in unfavorable weather conditions (Pinto et al., 2016; Nonnecke, 1989).

Most common:

• Boric acid (0.1–0.2% solution)—spraying flowering plants during flowering. Boron stimulates pollen germination and fruit set (Pinto et al., 2016; Kotov and Adritskaya, 2016).
• "Ovary" (and other gibberellin-based preparations)—stimulate fruit formation without fertilization (partial parthenocarpy). Especially effective in hot weather (Pinto et al., 2016).
• "Bud"—a stimulator of flowering and fruit set (Nonnecke, 1989).

Important: Growth regulators are an auxiliary means, not a replacement for normal pollination. They do not always give results in extreme heat (above 32 °C) or cold (below 15 °C) (Nonnecke, 1989).

4. Optimizing Growing Conditions

Create the most comfortable conditions for pollination (Bosland and Votava, 2012; Pinto et al., 2016):

• Maintain soil moisture at 70–80% field capacity during flowering. Lack of moisture leads to pollen sterilization and flower drop.
• Water plants in the morning so that by the time flowers open (around 9–10 a.m.), air humidity is optimal.
• Use drip irrigation—it does not increase air humidity around plants, reducing the risk of pollen sticking (Naik, 2003).
• In hot weather, carry out refreshing sprinkler irrigation during the day—it reduces air temperature and increases humidity, improving pollination (Naik, 2003; Tarakanov and Mukhin, 2003).
• Shading during the hottest hours (from 11 a.m. to 3 p.m.) helps lower temperature by 3–5 °C, preserving pollen viability (Russo, 2012).
• Ensure good nutrition, especially phosphorus and potassium. Phosphorus deficiency inhibits flowering, and potassium deficiency impairs pollen quality (Pinto et al., 2016).

5. Selecting Varieties for Your Region

For stable pollination in your region, choose varieties adapted to local climatic conditions (Pinto et al., 2016; Sundstrom, 1992):

• For hot regions (south, subtropics): varieties and hybrids resistant to heat, with good fruit set at high temperatures. For example, "California Wonder," "Gift of Moldova," "Volzhanin" (Pinto et al., 2016).
• For cold regions (north, temperate zone): early-maturing varieties that have time to bloom before heat or cold sets in. For example, "Lastochka," "Winnie-the-Pooh," "Kupets" (Pinto et al., 2016).
• Universal varieties: with high self-pollination capacity and resistance to temperature fluctuations.

Also keep in mind that sweet and hot peppers cannot be planted nearby. They easily cross-pollinate, and sweet peppers become bitter, while hot peppers lose some pungency (Pinto et al., 2016; Sundstrom, 1992). The minimum distance between them is 10–20 meters, preferably more (Nonnecke, 1989).

Cool Regions (North, Siberia, Non-Black Earth Zone)

• Main problem—cold during flowering (below 15 °C).
• Choose early-maturing, cold-tolerant varieties.
• Use covers (non-woven material, film) to raise temperature during flowering (Nonnecke, 1989).
• Plant seedlings at optimal dates so that flowering coincides with the warmest period.

Temperate Regions (Middle Zone)

• Problems mainly occur in hot summers (above 30 °C) or during prolonged rains and cold nights.
• Monitor weather forecasts and use shading in heat.
• Use covers during cold spells.

Hot Regions (South, Steppe, Subtropics)

• Main problem—heat (above 30–32 °C), which sterilizes pollen.
• Use shading, watering for cooling.
• Choose heat-tolerant varieties with good fruit set at high temperatures.
• During the hottest flowering periods (July-August), help plants with artificial pollination (Pinto et al., 2016).

Windy Regions

• Wind itself helps pollination, but strong winds can damage flowers and knock them off (Sundstrom, 1992).
• Use windbreaks and staking.
• In calm weather, use shaking.

Fungal Diseases

One of the most dangerous and widespread diseases of pepper, especially in rainy, cool weather (Akhatov et al., 2013; Pinto et al., 2016). The causative agent is a fungus-like organism (oomycete) that affects all parts of the plant.

Symptoms: Dark brown, blurry spots appear on leaves, especially along the leaf edge. In wet weather, a white cobweb-like coating—fungal sporulation—can be seen on the underside of the leaf. On stems and petioles—brown, elongated spots. On fruits—hard, browning areas, fruits may become deformed. With early infection, fruits become misshapen and unfit for consumption (Akhatov et al., 2013).

Development conditions: Favorable temperature—20–22 °C during the day and 10–12 °C at night, abundant dew, fog, rain. Above 25 °C, disease development slows. Spores can survive on plant debris and in soil (Akhatov et al., 2013; Pinto et al., 2016).

Control measures:

• Prevention: crop rotation (do not plant peppers after tomatoes, potatoes, eggplants), selection of resistant varieties and hybrids, avoid dense planting.
• Watering: only at the root, preferably in the morning so plants have time to dry. Avoid sprinkling in the evening.
• Spraying: at the first signs of disease, copper-containing preparations (Bordeaux mixture, copper oxychloride) are used. During widespread disease—systemic fungicides (Akhatov et al., 2013; Nonnecke, 1989).

A fungal disease affecting leaves, stems, and fruits (Akhatov et al., 2013; Pinto et al., 2016). Especially harmful in hot weather (23–30 °C) with short rains.

Symptoms: Brown, round or angular spots with characteristic concentric zoning (rings) appear on leaves, often with a black sporulation coating. Usually, lower, older leaves are affected. On fruits—dark, sunken spots that over time become covered with a black or dark olive coating. Fruits near the stalk are often affected (Akhatov et al., 2013).

Source of infection: Plant residues on which the fungus overwinters as conidia and mycelium, rarely—seeds (Akhatov et al., 2013).

Control measures:

• Prevention: crop rotation, destruction of plant residues.
• Spraying: with copper-containing preparations or modern fungicides (strobilurins) at the first symptoms (Akhatov et al., 2013).

A fungal disease especially common in hot, dry weather with relative humidity of 50–70% (Akhatov et al., 2013; Pinto et al., 2016). In open ground, it is less common than in greenhouses.

Symptoms: Chlorotic (yellowish) spots appear on the upper side of leaves, which then become necrotic. On the underside of leaves—a white powdery coating (fungal sporulation). Affected leaves turn yellow and drop. Fruits are not affected, but yield is reduced due to decreased photosynthetic surface (Akhatov et al., 2013).

Control measures:

• Prevention: crop rotation, weed control.
• Spraying: at the first symptoms—sulfur-based fungicides, potassium and sodium preparations (bicarbonates), or modern fungicides (Akhatov et al., 2013).

These are dangerous soil-borne fungal diseases that affect the vascular system of plants (Akhatov et al., 2013; Pinto et al., 2016). They are most common in southern regions, on warm soils, with long-term cultivation of solanaceous crops in one place.

Symptoms: Plants wilt, starting from the lower leaves. Leaves turn yellow, dry, and drop. On the cut stem, darkening of the vascular bundles is noticeable. In wet weather, a pinkish or white sporulation coating appears on affected tissues (Akhatov et al., 2013).

Source of infection: Soil and plant residues, where fungi can survive for many years (Akhatov et al., 2013).

Control measures:

• Crop rotation (return peppers to the original place no earlier than after 3–4 years) (Pinto et al., 2016).
• Growing resistant varieties and hybrids—this is the most effective method (Akhatov et al., 2013; Pinto et al., 2016).
• Soil improvement: application of well-rotted compost, biological products based on Trichoderma, green manures. Removal of diseased plants with roots (Akhatov et al., 2013).

A fungal disease that most often appears in the second half of summer at high air humidity and temperature fluctuations (Akhatov et al., 2013).

Symptoms: Gray, fluffy spots (fungal sporulation) appear on stems, leaves, and fruits. Fruits near the stalk are often affected, especially in varieties with "high shoulders" where moisture stagnates (Akhatov et al., 2013).

Control measures: Prevention—maintaining optimal humidity, timely removal of diseased leaves and fruits. In greenhouses—fungicides, in open ground—mainly prevention (Akhatov et al., 2013).

Bacterial Diseases

One of the most common bacterial diseases of peppers (Akhatov et al., 2013; Pinto et al., 2016). Transmitted through seeds and plant residues, actively spread by raindrops and watering.

Symptoms: On leaves—small, oily, dark, almost black irregular spots, often along leaf edges. On stems—elongated black spots. On fruits—black, raised spots with a light border, which then become sunken and form ulcers. Mature fruits are not affected (Akhatov et al., 2013).

Development conditions: High humidity and temperature (Akhatov et al., 2013).

Control measures:

• Prevention: use of healthy seeds (disinfection), crop rotation, resistant varieties.
• Spraying: copper-containing preparations, biological products based on Bacillus subtilis (Akhatov et al., 2013).

A quarantine disease that is less common but very dangerous (Akhatov et al., 2013). Transmitted through seeds.

Symptoms: Wilting of individual shoots, brown spots on leaves, "bird's eye" spots on fruits (light spots with a dark center) (Akhatov et al., 2013).

Control measures: Prevention—seed disinfection, crop rotation, removal of diseased plants. Chemical agents—copper-containing (Akhatov et al., 2013).

Viral Diseases

Viruses are one of the most serious problems for peppers, especially in regions with a high number of vectors (aphids, thrips, whiteflies) (Akhatov et al., 2013; Pinto et al., 2016).

A highly contagious virus that can be spread mechanically (through hands, tools) and with seeds (Akhatov et al., 2013; Pinto et al., 2016).

Symptoms: Chlorosis, mosaic patterning, and wrinkling of leaves. Plants are stunted. Later, dark stripes and necrosis appear on stems and petioles. Fruits become smaller (Akhatov et al., 2013).

Control measures:

• Resistant varieties and hybrids—the main method (Akhatov et al., 2013; Pinto et al., 2016).
• Seed disinfection (heating at 70 °C for 3 days or treatment with 10% sodium phosphate) (Akhatov et al., 2013).
• Control of vectors (aphids).
• Hygiene—washing hands and tools, especially when working with diseased plants (Akhatov et al., 2013).

A dangerous virus transmitted by aphids (especially Myzus persicae) (Akhatov et al., 2013; Pinto et al., 2016).

Symptoms: Diverse—stunting, leaf curling, deformation, chlorosis, mosaic. Fruits are small, misshapen. May manifest in green, yellow, brown, and dwarf forms (Akhatov et al., 2013).

Control measures: Growing resistant varieties, removal of diseased plants, control of aphid vectors, placing crops away from cucurbits (Akhatov et al., 2013; Pinto et al., 2016).

A dangerous virus transmitted by thrips (Frankliniella occidentalis—western flower thrips) (Akhatov et al., 2013; Pinto et al., 2016). Occurs in warm regions.

Symptoms: Young leaves acquire a bronze tint, necrotic ring spots and zigzags appear. Fruits become covered with ring spots and become deformed (Akhatov et al., 2013).

Control measures: Thrips control is the main measure. Use of resistant varieties, removal of weed reservoirs. Thorough cleaning of plant residues (Akhatov et al., 2013).

Aphids (Myzus persicae—green peach aphid, Aphis gossypii—cotton aphid)

One of the most common and dangerous pests. Aphids suck sap from young shoots and leaves, causing deformation, curling, and wilting. The honeydew excreted by aphids promotes the development of sooty mold. But the main danger—they are vectors of many viruses (Akhatov et al., 2013; Pinto et al., 2016).

Signs: Clusters of aphids on the underside of leaves, on young shoots, buds, and flowers. Leaves curl, become covered with sticky honeydew (Akhatov et al., 2013).

Control measures:

• Biological: attracting and preserving natural enemies—ladybugs (Coccinellidae), lacewings, hoverflies, parasitic wasps (Aphidius colemani) (Akhatov et al., 2013; Pinto et al., 2016).
• Agrotechnical: control of weed reservoirs, growing trap plants, washing aphids off with a jet of water (Pinto et al., 2016).
• Chemical: insecticides (but with caution to avoid killing beneficial insects). Recommended preparations: Actellik, Fufanon, Aktara, Fitoverm, Akarin (Akhatov et al., 2013).
• Traditional remedies: infusions of garlic, onion, tobacco, nettle, soap solution (Pinto et al., 2016; Sundstrom, 1992). But they are effective only at early stages.

Thrips (Thrips tabaci, Frankliniella occidentalis and others)

Small insects feeding on plant sap. They cause great damage, especially in hot weather. They are also vectors of viruses (especially the western flower thrips, F. occidentalis—vector of TSWV) (Akhatov et al., 2013; Pinto et al., 2016).

Signs: On leaves—small white, silvery spots (necroses), leaves deform. On fruits—silvery or brown spots, deformation, loss of marketable quality (Akhatov et al., 2013).

Control measures:

• Biological: predatory bugs Orius (Orius spp.)—effective predators of thrips (Akhatov et al., 2013; Pinto et al., 2016).
• Agrotechnical: weed control, maintaining optimal humidity.
• Chemical: insecticides (Actellik, Fufanon, Aktara, etc.) (Akhatov et al., 2013). In open ground, treatments are carried out only with significant pest numbers.

Spider Mite (Tetranychus urticae and others)

One of the most dangerous pests of peppers in hot, dry weather (Akhatov et al., 2013; Pinto et al., 2016). Small arachnids feeding on plant sap.

Signs: On the underside of leaves, fine webbing is visible. Leaves become pale, covered with small yellowish dots (punctures), then dry up and drop. With severe infestation—plant death (Akhatov et al., 2013).

Control measures:

• Prevention: regular watering and spraying of plants (mites do not like high humidity) (Akhatov et al., 2013; Pinto et al., 2016).
• Biological: predatory mites (Phytoseiulus persimilis and others) (Akhatov et al., 2013).
• Chemical: acaricides (Fitoverm, Actellik, etc.). Use only with mass infestation.

Colorado Potato Beetle (Leptinotarsa decemlineata)

On peppers, the Colorado potato beetle moves from potatoes or tomatoes. Especially dangerous when potato plantings are nearby (Akhatov et al., 2013; Pinto et al., 2016). Both the adult beetle and its larvae cause damage by eating leaves (sometimes completely skeletonizing the bush).

Control measures:

• Agrotechnical: spatial isolation from potato fields, destruction of egg masses, manual collection of beetles and larvae (Akhatov et al., 2013).
• Chemical: insecticides (Bankol, Decis, Zolon, etc.) (Akhatov et al., 2013). It is important to alternate preparations to avoid resistance.

Cutworms (Caterpillars) (Helicoverpa armigera, Spodoptera litura and others)

Caterpillars of night-flying moths. Especially dangerous for pepper fruits (Akhatov et al., 2013; Pinto et al., 2016). Young caterpillars feed on leaves, then bore into fruits, eating the contents, causing rot.

Signs: Entry holes near the stalk are visible on fruits, fruits rot, and caterpillar frass is found inside (Akhatov et al., 2013).

Control measures:

• Agrotechnical: early harvest, collection and destruction of damaged fruits, weed control, plowing to destroy pupae (Akhatov et al., 2013).
• Biological: use of predatory bugs (Podisus maculiventris, Picromerus bidens), release of Trichogramma (egg parasitoid) (Akhatov et al., 2013).
• Chemical: insecticides, but their use in open ground is limited (Akhatov et al., 2013).

Whitefly (Trialeurodes vaporariorum, Bemisia tabaci)

A small insect often found in open ground in southern regions (Akhatov et al., 2013). Whiteflies suck plant sap, excreting honeydew on which sooty molds develop. It is a vector of viruses (Tomato yellow leaf curl virus). On peppers, whiteflies are less aggressive than on tomatoes but can cause significant damage (Akhatov et al., 2013; Pinto et al., 2016).

Control measures: Same as for tomatoes. Use insecticides as a last resort. Use of entomophages (Encarsia formosa) is limited in open ground due to the difficulty of their release (Akhatov et al., 2013).

Technical Maturity

This is the stage when the fruit has reached the typical size and shape for the variety but has not yet acquired its final color (green, cream, light yellow, purple depending on the variety) (Pinto et al., 2016). The seeds inside the fruit are not yet fully mature, they are in the milky or waxy stage of ripeness.

Signs of technical maturity:

• Fruit has reached the typical size and shape for the variety (Bosland and Votava, 2012).
• Skin is dense, shiny, glossy (Nonnecke, 1989).
• Color corresponds to the variety at technical maturity (green, light yellow, cream, purple) (Pinto et al., 2016).
• Seeds inside the fruit are not yet mature (light, soft).
• Fruit is easily removed from the stalk with a characteristic slight crack (Bosland and Votava, 2012).

Why harvest at technical maturity:

• Fresh consumption (green sweet pepper is the most common option) (Sundstrom, 1992).
• For canning, pickling, freezing.
• To stimulate the formation of new ovaries—early and regular harvesting at technical maturity increases total yield by 20–30% (Pinto et al., 2016; Nonnecke, 1989).

When to harvest: Usually 35–45 days after fruit set (Pinto et al., 2016). For most varieties—90–120 days from emergence (Bosland and Votava, 2012).

Biological (Physiological) Maturity

This is the stage of full fruit ripening, when it acquires its final color (red, orange, yellow, brown, purple) and full flavor (Bosland and Votava, 2012; Pinto et al., 2016). Seeds are fully mature and become hard.

Signs of biological maturity:

• Full coloring in the varietal color (red, yellow, orange) (Pinto et al., 2016).
• Skin becomes denser, glossier (Sundstrom, 1992).
• Flesh becomes sweeter, more aromatic, containing more vitamins (especially C and carotene) (Nonnecke, 1989).
• Fruit easily separates from the stalk.

Why harvest at biological maturity:

• For fresh consumption—red, yellow, orange peppers are significantly sweeter and more aromatic than green ones (Pinto et al., 2016).
• For paprika production (red pepper, dried and ground) (Sundstrom, 1992).
• For seed production (Nonnecke, 1989).
• For long-term storage (some varieties) (Bosland and Votava, 2012).

When to harvest: 7–14 days later than technical maturity (on average 50–60 days after fruit set) (Pinto et al., 2016). Depending on the variety—from 120 to 160 days from emergence (Bosland and Votava, 2012).

Table: Differences Between Technical and Biological Maturity

(Compiled from: Bosland and Votava, 2012; Pinto et al., 2016; Nonnecke, 1989; Sundstrom, 1992)

Important: Many pepper varieties pass through intermediate stages during ripening (e.g., from green to yellow, then to red). In some varieties, fruits at technical maturity are purple, and at biological—red. Know the characteristics of your variety (Pinto et al., 2016).

How to Properly Remove Fruits

1. Use a pruner or sharp knife. Peppers are better cut rather than pulled off. Pulling can damage the plant, especially fragile branches (Bosland and Votava, 2012; Pinto et al., 2016). Leave a stalk 2–3 cm long—this improves fruit keeping quality (Nonnecke, 1989).

2. Do not pull the fruit downward. This can break the branch or damage the stem. Cut the fruit carefully, without damaging neighboring fruits and leaves (Sundstrom, 1992).

3. Harvest in dry weather. Wet fruits spoil faster, and diseases develop more easily on them. The best time is morning after dew has dried (Pinto et al., 2016; Nonnecke, 1989).

4. Do not damage the fruit skin. Any scratches, punctures, dents are entry points for diseases and rots (Bosland and Votava, 2012).

5. Do not allow overripening. Overripe fruits lose firmness, become soft, and may crack. In addition, they delay the formation of new ovaries (Pinto et al., 2016).

Harvest Frequency

Pepper fruits in waves: after picking ripe fruits, active growth of new ovaries begins (Sundstrom, 1992). Therefore, regular harvesting stimulates further fruiting.

Recommended frequency:

• At technical maturity (green fruits): every 5–7 days (Pinto et al., 2016).
• At biological maturity: every 3–5 days (some varieties require daily harvesting) (Bosland and Votava, 2012).
• Hot pepper: less often—as they ripen (Pinto et al., 2016).

Important: The more often you pick fruits at technical maturity, the more new fruits will set. This is especially relevant for sweet peppers and for commercial production. Regular harvesting can increase the total yield by 20–30% (Nonnecke, 1989; Pinto et al., 2016).

What to Do with the First Harvest

The first "crown" fruit (which forms in the first fork) is usually recommended to be removed at the flower stage (see Chapter 7) to stimulate bush growth. If you left it, such a fruit is often large, but its formation delays the growth of the rest. Harvest it as early as possible, at technical maturity, to stimulate the growth of side shoots (Pinto et al., 2016; Nonnecke, 1989).

Sorting and Grading

Immediately after harvesting, fruits are sorted (Pinto et al., 2016; Nonnecke, 1989):

• Standard—healthy, correct shape and color, no damage, typical size for the variety.
• Non-standard—deformed, damaged by pests or diseases, small, with mechanical damage. They are used for food first.
• For seeds—the largest, healthy fruits of correct shape (left until fully ripe).

Preparation for Storage

Washing: Peppers are usually not washed before storage, as moisture promotes rot development. If fruits are dirty, they can be wiped with a dry cloth or washed and thoroughly dried (Nonnecke, 1989). In some cases, washing in chlorinated water (0.005% chlorine) is used for disinfection, but this is more typical for industrial production (Pinto et al., 2016).

Drying: Fruits must be dry before storage. Moisture promotes the development of gray mold and other diseases (Bosland and Votava, 2012).

Sorting: Remove all fruits with signs of damage, cracks, traces of diseases—they will spoil neighboring ones.

Storage Conditions

Storage conditions depend on the stage of maturity (Bosland and Votava, 2012; Nonnecke, 1989; Sundstrom, 1992):

Important nuances:

• Pepper is sensitive to cold. At temperatures below 7 °C, green fruits may develop "chilling injury" (spots, dents), especially during long-term storage (Nonnecke, 1989). Red fruits are more resilient but also do not tolerate frost.
• Do not store peppers next to apples and bananas—they emit ethylene, which accelerates ripening and can cause yellowing of green fruits (Pinto et al., 2016).
• Humidity should be high (90–95%) to prevent fruits from losing turgor and wilting. At home, this is difficult to achieve, so use the vegetable drawer of the refrigerator or plastic bags with holes (Nonnecke, 1989).
• Do not store peppers in plastic bags without air access—this leads to rotting.

Storing Hot Peppers

Hot peppers are stored differently—they are often dried (Bosland and Votava, 2012; Sundstrom, 1992):

• Air drying: fruits are threaded on a string (by the stalk) and hung in a dry, well-ventilated place. Drying takes 1–2 weeks until fruits are completely dry and brittle (Nonnecke, 1989).
• Oven drying: at 40–50 °C with the door slightly open (to let moisture out), until completely dry.
• Storage of dried peppers: in airtight jars, in a dry, dark place. Shelf life—up to 1–2 years (Bosland and Votava, 2012).
• Ground pepper: store in tightly closed jars in a dry, dark place.

Ripening of Green Fruits

If there is little time left before the end of the season and there are many green fruits on the bushes, they can be harvested at technical maturity and ripened indoors (Nonnecke, 1989; Tarakanov and Mukhin, 2003). But remember: ripening does not improve taste, only changes color. In taste, such fruits are inferior to those ripened on the bush (Bosland and Votava, 2012).

How to ripen:

• Fruits are placed in a warm (20–25 °C), dry, well-ventilated room with humidity of 80–85% (Nonnecke, 1989).
• Spread in one or two layers, in the dark or in diffused light (in light, color becomes more intense).
• Periodically sorted, removing rotten fruits.
• Ripening period: 7–14 days (Pinto et al., 2016; Nonnecke, 1989).
• Accelerated ripening: using ethylene (1:2000)—used on an industrial scale, not required at home.

Important: In red varieties, when ripening in the dark, the color may be paler than in the sun. But for home use, this is not critical (Nonnecke, 1989).

1. Autumn Covers

Using covering materials in autumn can extend fruiting by 2–3 weeks and even more (Nonnecke, 1989).

How it works:

• Non-woven covering materials (spunbond, lutrasil) protect from the first light frosts (down to −2…−3 °C) (Bosland and Votava, 2012).
• Film (perforated) protects from frosts down to −5 °C but requires ventilation during the day.
• Double covering (film + non-woven material)—for the most severe conditions.

Timing: Covers are installed at the first frost forecast, usually in late August—September (depending on the region). During the day, the cover can be removed or opened for ventilation if the temperature is not low. Finally, it is removed after frosts are no longer forecast (Nonnecke, 1989).

2. Topping Tips and Removing Excess Ovaries

3–4 weeks before the expected frosts (usually in late August—early September), topping of the main stems and skeletal shoots is carried out. This allows redirecting nutrients to already formed ovaries and accelerating their ripening (Pinto et al., 2016; Nonnecke, 1989).

How to do:

• Remove all growth points on the main and side shoots, leaving 2–3 leaves above the top ovary (Pinto et al., 2016).
• Remove all flowers and small ovaries that will not have time to ripen before cold weather.
• Remove lower, old, or diseased leaves to improve ventilation and lighting of remaining fruits.
• Leave on the plant only the most developed fruits and ovaries.

Effect: Accelerates ripening by 7–14 days, fruits become larger and of higher quality (Nonnecke, 1989; Tarakanov and Mukhin, 2003).

3. Using Varieties of Different Ripening Periods

Combine early, medium, and late varieties to stretch the harvest period (Pinto et al., 2016; Nonnecke, 1989).

• Early varieties (technical maturity in 90–100 days from emergence)—for early harvest.
• Medium (100–120 days)—main fruiting.
• Late (>120 days)—for late harvest and autumn consumption.

Planting several varieties with different ripening periods allows you to harvest from July to October (depending on the region) (Pinto et al., 2016).

4. Remontant and Repeat Flowering

In some pepper varieties (especially sweet hybrids), after harvesting the main wave of yield, new flowering and fruit set begin. This property is called remontancy (Pinto et al., 2016; Nonnecke, 1989). To stimulate repeat flowering:

• Regularly harvest fruits at technical maturity, not allowing them to overripen on the bush.
• Conduct fertilization with phosphorus-potassium fertilizers (superphosphate + potassium sulfate)—it stimulates flowering and setting of new fruits (Pinto et al., 2016).
• Remove old, fruited branches.
• In autumn (if climate allows), prune the bush—remove old shoots, leaving 2–3 young ones that will give an autumn harvest. However, this is more labor-intensive and not suitable for all varieties (Nonnecke, 1989).

5. Digging Up Plants for Ripening

If frost has arrived and there are still many green fruits on the bushes, you can dig up the plants with roots and place them indoors for ripening (Balashev and Zeman, 1981; Nonnecke, 1989).

How to do:

• A few days before frost, dig up bushes with a large root ball, trying not to damage roots.
• Place them in a cool (15–20 °C), dry, dark or diffused-light room (Nonnecke, 1989).
• Water moderately so that roots do not dry out.
• Fruits will ripen within 2–4 weeks.

Important: Ripening on dug-up plants gives better-quality fruits (closer in taste to those ripened on the bush) than ripening of picked fruits (Bosland and Votava, 2012). But this method is only suitable for small volumes (Nonnecke, 1989).

6. Mulching and Warm Beds

• Mulch helps protect roots from freezing, especially if you use organic mulch (humus, peat, straw) with a layer of 10–15 cm in autumn (Pinto et al., 2016; Nonnecke, 1989).
• Warm beds (with organic "fuel"—manure, plant residues) extend the growing season due to heat release during decomposition (Nonnecke, 1989). This is especially relevant in cold regions.

7. Harvesting in Several Terms

Harvesting fruits at technical maturity throughout the season stimulates the formation of new ovaries, prolonging the fruiting period. If you harvest fruits at biological maturity (red, yellow), the plant quickly goes into a dormant state, and the formation of new ovaries slows down (Nonnecke, 1989; Pinto et al., 2016). Therefore, to extend the season:

• Harvest the main volume at technical maturity (green, cream).
• Leave some fruits (for eating, selling) until biological maturity, but not too many.
• Regular harvesting is mandatory (Sundstrom, 1992).

What is done wrong

• Planting peppers in the shade, on the north side of buildings, in lowlands where cold air stagnates.
• Ignoring crop rotation—planting peppers after tomatoes, potatoes, eggplants, or in the same place for several years in a row.
• Choosing a site with heavy, clayey, acidic, or waterlogged soils.

Why this is a mistake

Pepper is a light- and heat-loving crop. In the shade, it stretches, blooms poorly, ovaries drop, fruits become smaller (Pinto et al., 2016). In lowlands, it suffers from frost and overwatering. Solanaceous predecessors are a source of common diseases (fusarium, verticillium, late blight) that accumulate in the soil (Akhatov et al., 2013). Heavy soils warm up poorly, roots suffocate, plants suffer from oxygen deficiency (Nonnecke, 1989).

How to avoid

• Choose a sunny, wind-protected site, preferably on the south or southwest side.
• Observe crop rotation—do not plant peppers after solanaceous crops, return to the original place no earlier than after 3–4 years (Pinto et al., 2016).
• Improve the structure of heavy soils—add sand, humus, peat, make high ridges (Nonnecke, 1989).

What is done wrong

• Do not apply organic matter or apply it incorrectly (fresh manure).
• Overfeed with nitrogen fertilizers.
• Ignore the application of phosphorus, potassium, and micronutrients.
• Do not check and adjust soil acidity (pH).

Why this is a mistake

Fresh manure causes "luxuriant growth"—rapid green mass growth at the expense of fruiting, delays flowering, and can provoke diseases (Sundstrom, 1992). Excess nitrogen makes plants loose, more vulnerable to diseases and pests, reduces fruit storage ability (Pinto et al., 2016). Phosphorus and potassium deficiency leads to weak flowering, ovary drop, small and tasteless fruits (Nonnecke, 1989). Acidic soils (pH below 5.5–6.0) cause calcium and magnesium deficiency, leading to blossom-end rot of fruits (Pinto et al., 2016).

How to avoid

• Apply organic matter only in rotted form (humus, compost) in autumn or spring during digging (Nonnecke, 1989).
• Maintain NPK balance: do not overfeed with nitrogen, ensure sufficient phosphorus and potassium (Pinto et al., 2016).
• Carry out liming on acidic soils (2–3 months before planting) (Nonnecke, 1989).
• Use micronutrients (boron, zinc, magnesium, iron) as foliar feeds (Pinto et al., 2016).

What is done wrong

• Planting overgrown, unhardened seedlings.
• Burying seedlings when planting.
• Planting too early, in cold soil.
• Damaging roots during transplanting.

Why this is a mistake

Overgrown and unhardened seedlings take a long time to recover, pause in growth, and lose the first flowers (Sundstrom, 1992). Burying pepper (unlike tomato) does not give additional roots, but on the contrary, leads to stem rotting (Pinto et al., 2016). Planting in cold soil (below 13–15 °C) causes stress, roots do not function, plants do not establish (Nonnecke, 1989). Root damage during transplanting slows establishment (Pinto et al., 2016).

How to avoid

• Grow healthy, stocky seedlings (age 50–70 days, height 15–25 cm, 6–10 leaves) (Pinto et al., 2016).
• Harden seedlings 10–14 days before transplanting (Nonnecke, 1989).
• Plant in warmed soil (not below 15 °C) on a cloudy day or in the evening (Bosland and Votava, 2012).
• Plant at the same depth as in the pot, without burying (Pinto et al., 2016).
• Carefully remove seedlings from containers without damaging the root ball (Nonnecke, 1989).

What is done wrong

• Watering with cold water.
• Watering in the evening on leaves, creating conditions for fungal diseases.
• Allowing soil to dry out or become waterlogged.
• Watering often but in small amounts (surface watering).

Why this is a mistake

Cold water causes "physiological drought"—roots stop absorbing water, the plant wilts (Naik, 2003). Evening watering on leaves creates favorable conditions for late blight, powdery mildew, and bacterial diseases (Akhatov et al., 2013; Pinto et al., 2016). Soil drying leads to flower and ovary drop, overwatering—to root rotting (Bosland and Votava, 2012). Surface watering does not reach the bulk of the roots (Naik, 2003).

How to avoid

• Water with warm water (20–25 °C) in the morning, at the root (Naik, 2003; Pinto et al., 2016).
• Use drip irrigation—the most effective method for peppers (Naik, 2003).
• Maintain soil moisture at 70–80% field capacity (Pinto et al., 2016).
• Water less often but abundantly (3–4 L per plant) so that water penetrates deep into the root zone (Nonnecke, 1989).

What is done wrong

• Overfeeding with nitrogen during fruiting.
• Not applying phosphorus and potassium in the right phases.
• Ignoring micronutrients (boron, calcium, magnesium).
• Applying fertilizers to dry soil.

Why this is a mistake

Excess nitrogen during fruiting leads to "luxuriant growth," delays fruit ripening, impairs taste and storage ability (Pinto et al., 2016; Sundstrom, 1992). Phosphorus deficiency slows flowering and fruit set, potassium deficiency impairs fruit quality (Nonnecke, 1989). Calcium deficiency causes blossom-end rot of fruits (Bosland and Votava, 2012). Applying fertilizers to dry soil causes root burn (Pinto et al., 2016).

How to avoid

• Apply nitrogen only at the beginning of the growing season and in the first feeding, then mainly phosphorus and potassium (Pinto et al., 2016).
• Use foliar feeding with micronutrients (boron, calcium, magnesium) (Pinto et al., 2016).
• Always water first, then apply fertilizers (Nonnecke, 1989).
• Apply fertilizations fractionally, not in one large dose (Pinto et al., 2016).

What is done wrong

• Not removing the "crown" flower.
• Suckering short determinate varieties.
• Not staking tall varieties.
• Removing too many leaves.

Why this is a mistake

Left crown flower "takes" strength from the plant, weakens the bush, reduces overall yield (Pinto et al., 2016). In short varieties, suckering reduces yield, as each shoot produces fruits (Sundstrom, 1992). Without staking, tall varieties break under the weight of fruits and from wind (Russo, 2012). Removing too many leaves weakens photosynthesis (Nonnecke, 1989).

How to avoid

• Remove the crown flower in all varieties (Pinto et al., 2016).
• Do not sucker short determinate varieties (Sundstrom, 1992).
• For tall varieties, sucker moderately, leaving 2–3 strong shoots (Pinto et al., 2016).
• Remove only lower, old, or diseased leaves, no more than 2–3 at a time (Pinto et al., 2016).
• Be sure to stake tall varieties (Russo, 2012).

What is done wrong

• Not accounting for weather conditions during flowering.
• Planting sweet and hot peppers nearby.
• Killing insect pollinators with insecticides during flowering.
• Not helping plants in heat or cold (shading, covering).

Why this is a mistake

Pepper does not set fruit at temperatures above 30 °C (pollen is sterile) and below 15 °C (pollen does not germinate) (Pinto et al., 2016). Proximity of sweet and hot peppers leads to cross-pollination—sweet becomes bitter (Nonnecke, 1989). Killing insects reduces the fruit set percentage (Pinto et al., 2016). Lack of help in extreme weather leads to flower drop and yield loss (Bosland and Votava, 2012).

How to avoid

• In heat, use shading and refreshing watering (Pinto et al., 2016; Naik, 2003).
• In cold—use covers (Nonnecke, 1989).
• Do not plant sweet and hot peppers nearby (minimum distance 10–20 meters) (Sundstrom, 1992).
• Do not apply insecticides during flowering (Pinto et al., 2016).
• Use artificial pollination (shaking, brush) in unfavorable weather (Nonnecke, 1989).

What is done wrong

• Ignoring prevention and starting control when the disease has already spread.
• Using chemical preparations unnecessarily.
• Not alternating preparations, causing resistance.
• Ignoring biological protection methods.

Why this is a mistake

Late treatment is often ineffective, especially for viral and bacterial diseases (Akhatov et al., 2013). Excessive chemical use kills beneficial insects, leads to accumulation of harmful substances (Nonnecke, 1989). Resistance makes preparations useless (Akhatov et al., 2013). Ignoring biological methods deprives you of natural helpers (Pinto et al., 2016).

How to avoid

• Prevention is the basis: crop rotation, healthy seeds, optimal agrotechnics (Pinto et al., 2016).
• Regularly inspect plants, remove diseased ones at the first signs (Akhatov et al., 2013).
• Use biological preparations (Fitosporin, Trichoderma, biopreparations against pests) (Pinto et al., 2016; Akhatov et al., 2013).
• Use chemicals only as a last resort, strictly according to instructions and with waiting periods (Nonnecke, 1989; Akhatov et al., 2013).
• Alternate preparations from different groups to avoid resistance (Akhatov et al., 2013).

What is done wrong

• Harvesting too late (overripe).
• Pulling fruits, damaging the plant.
• Harvesting wet, moist fruits.
• Not sorting the harvest before storage.

Why this is a mistake

Overripe fruits delay the formation of new ovaries, reducing total yield (Pinto et al., 2016). Pulling fruits can break branches, damage the plant (Bosland and Votava, 2012). Wet fruits are more quickly affected by rots (Nonnecke, 1989). Lack of sorting leads to rapid spoilage of the entire harvest (Sundstrom, 1992).

How to avoid

• Harvest fruits at technical maturity (green, cream, purple) regularly, every 5–7 days (Pinto et al., 2016).
• Cut fruits with a pruner, leaving a 2–3 cm stalk (Bosland and Votava, 2012).
• Harvest only in dry weather, in the morning after dew has dried (Nonnecke, 1989).
• Sort fruits by quality and size before storage (Pinto et al., 2016).
• For ripening, use only healthy, undamaged fruits (Nonnecke, 1989).

What is done wrong

• Storing at incorrect temperature (too cold for green—below 7 °C, or too hot).
• Storing with ethylene-emitting fruits (apples, bananas).
• Not ensuring proper humidity (too dry or too wet).
• Storing without sorting and checking.

Why this is a mistake

Too low temperature causes chilling injury (spots, loss of firmness) (Nonnecke, 1989). Ethylene accelerates overripening and spoilage (Pinto et al., 2016). Low humidity leads to wilting, high humidity—to rotting (Sundstrom, 1992). Without checking, one diseased fruit can ruin the entire harvest (Bosland and Votava, 2012).

How to avoid

• Store green fruits at 7–10 °C, red—at 4–7 °C, humidity 90–95% (Nonnecke, 1989).
• Do not store peppers next to apples, bananas, pears (Pinto et al., 2016).
• Use plastic bags with holes to maintain humidity (Nonnecke, 1989).
• Periodically check the harvest, remove spoiled fruits (Bosland and Votava, 2012).
• Dry hot peppers in a dry, dark, ventilated place (Sundstrom, 1992).

What is done wrong

• Not extending the season in autumn (lack of covers, topping).
• Not removing plant residues after the season.
• Not carrying out preventive soil sanitation.

Why this is a mistake

Without covers, a significant part of the harvest can be lost during the first frosts (Russo, 2012). Plant residues are a source of diseases for the next year (Akhatov et al., 2013). Ignoring soil sanitation leads to the accumulation of pathogens (Pinto et al., 2016).

How to avoid

• Use covers in autumn to protect from frosts (Nonnecke, 1989).
• Carry out topping of tips and removal of excess ovaries 3–4 weeks before frost (Pinto et al., 2016).
• Collect and burn all plant residues after harvesting (Akhatov et al., 2013).
• Carry out deep digging of soil with organic fertilizers (Nonnecke, 1989).
• If necessary, apply biological preparations for soil sanitation (Akhatov et al., 2013).
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