Maize

Economic importance

Maize grain contains 65–70% carbohydrates, 9–12% proteins, 4–8% fat, 1.5% mineral salts, 2.5% fiber, vitamins, and 14–15% water. The grain is used to produce flour, groats, flakes, canned products (sweet maize), starch, ethyl alcohol, dextrin, beer, glucose, sugar, molasses, syrups, honey, maize oil (the germ of the grain contains up to 30% fat), vitamin E, ascorbic acid, and glutamic acid. Immature cobs are eaten raw, boiled, or canned. Female flower columns are used in medicine. Stems, leaves, and cobs can be used to produce paper, linoleum, viscose, activated carbon, artificial cork, plastics, and anesthetics.

Maize flour contains little gluten, so it is unsuitable for bread baking; it is added to bakery and confectionery products. Maize oil is semi-drying, with an iodine value of 111–133.

Maize grain serves as feed for agricultural animals. 1 kg of grain equals 1.34 feed units and contains 78 g of digestible protein. It is a valuable component of mixed feeds. Maize grain protein contains few essential amino acids — lysine and tryptophan — and is rich in a protein of low feed value — zein.

In Russia, maize is the main silage crop. For these purposes, cobs in the milk-wax or wax ripeness phase are used separately or together with leaves and stems. For ensiling, dry stems are suitable in a mixture with succulent crops, for example fodder gourds, pumpkin, and sugar beet tops. Silage is distinguished by good digestibility and has dietary properties. 100 kg of silage made from maize in the milk-wax ripeness phase contains 21–28 feed units and up to 1.8 kg of digestible protein. To increase the protein content in silage, leguminous grasses or fodder beans are added in mixed compacted crops.

Maize can be used for green fodder rich in carotene. The dry leaves, stems, and cob cores remaining after harvesting for grain can also be used for feed, sometimes in a mixture with succulent feeds. 100 kg of maize straw equals 37 feed units; 100 kg of ground cobs equals 35 feed units. Green leaves and stems are also used for feed.

As a row crop, maize serves as a good predecessor in crop rotation. Its crops help free fields from weeds, and it has almost no common pests and pathogens with cereals. After maize, a large amount of plant residues remains. When harvested for grain, maize is a good predecessor of cereal crops, and when grown for green fodder it is a fallow-occupying crop. It has become widespread in aftercut, stubble, and repeated crops. It is also used as wings, and in the Central Black Earth zone and North Caucasus as a fallow-occupying crop for green fodder and silage.

When cultivating maize for grain, pumpkin and beans are planted as compacting crops in the interrows.

History of the crop

Maize is an ancient crop, as evidenced by remains of cobs dated to approximately 5000 BC, found during excavations of the Tehuacan Cave in Mexico. It is estimated that domestication began around this time. In the pre-Columbian era, it was one of the main food crops of the indigenous peoples of Central and South America.

The origin of maize of the species Zea mays L. has not yet been deciphered by phylogenetic systematics, but it is considered to originate from Central and South America, the tropical and subtropical zones, as indicated by archaeological finds of pollen, panicles, grain, and cobs of primitive maize forms and by the results of genetic and cytoembryological studies. In Mexico, new species of the tribe Maydeae have been discovered, belonging to teosintes and maize — Zea perennis and Zea diploperennis.

The ancestor of maize is generally considered to be teosinte, Zea mays mexicana. Present-day maize plants can pollinate teosinte, and hybrid seeds are formed, but the resulting progeny is not useful. One theory suggests that the ancestor was some now extinct form of pod corn and that teosinte is a mutant of pod corn. However, wild species of pod corn have not been found.

Columbus reported the discovery of a new plant soon after his discovery of America. The first samples reached Europe at the end of the 15th century. Initially maize was cultivated as an ornamental plant. Later in France, Italy, and Portugal maize was recognized as a food crop, then as a feed crop. In the 16th century maize spread rapidly in areas with favorable cultivation conditions: to North Africa, India, and China. In Russia it became known in the 12th century and spread rapidly in the steppe zone. In the second half of the 19th century attempts were made to cultivate it in Moscow, Smolensk, and some other provinces, but this did not produce results.

At present maize is a highly domesticated plant, incapable of growing without human assistance, since the grain almost does not shatter, cobs break off rarely, and the stem is sufficiently strong.

Cultivation areas and yield

Maize has become widespread in the world due to its high nutritional qualities, good productivity, and ability to adapt to growing conditions. Cultivation areas extend from tropical latitudes to Scandinavia. In world agriculture, sown areas amount to 130–140 million ha, with 22–23% of them in the USA, while yielding up to 60% of the gross world grain harvest. Maize crops account for 20% of the sown area of cereal crops. In Brazil sown areas amount to 12.4 million ha, in India — 5.8 million ha, in Argentina — 3.2 million ha. Large sown areas exist in Mexico, some countries of southeastern Europe (Romania, Bulgaria, Hungary), and China.

The gross grain harvest in the world is 600 million t, or 29% of the gross harvest of cereals. Average yield is 4.2 t/ha. Statistics (worldwide) on production for green fodder and silage are not kept.

In the USSR in 1982, the sown area of maize for grain was 4.2 million ha, and for silage and green fodder — 18.1 million ha. The main cultivation areas are in Stavropol and Krasnodar Krai, in the Central Black Earth zone, the Volga region, southern Siberia, as well as in Transcaucasia, Ukraine, Moldova, and Central Asia. For silage and green fodder — also in the Non-Black Earth zone, Siberia, and the Far East.

Average yield for grain in 1980–1982 was 2.8 t/ha. Maximum yield under favorable climatic conditions in the main cultivation areas (in Ukraine, the North Caucasus, Georgia, Azerbaijan, and Central Asia) and with a high level of agrotechnology reached 5.0–6.0 t/ha of dry grain; under irrigation — up to 8.0–10.0 t/ha, and of silage mass — 80–100 t/ha.

The introduction of industrial cultivation technology in the USSR in 1981 on an area of 2.37 million ha ensured a yield increase compared with traditional mechanized technology of 9.7 c/ha, or 55%.

In the Non-Black Earth zone, as well as in Belarus and the Baltics, the yield of silage mass reaches 50–60 t/ha of green mass.

The sown area in Russia in 1997 was 0.92 million ha (for grain); in 2001–2005 — 0.7 million ha. Sown areas for green fodder and silage in 1997 were 5.0 million ha and 2.5 million ha in 2001–2005. Average yield — 2.9 t/ha. Gross grain harvest in 2001–2005 was 2 million t. Gross harvest of feed mass in 2001–2005 — 32.2 million t, with an average yield of 13.7 t/ha.

Botanical description

Maize is an annual plant belonging to the grass family (Poaceae). It is monoecious, dioecious, and cross-pollinated. It does not occur in the wild.

Subspecies

According to the shape, chemical composition, and internal structure of the caryopses, eight subspecies of maize are distinguished (terms in italics are not botanically recognized, but have been used in other publications to identify different types of maize grains):

• dent;
• flint;
• starchy;
• sweet;
• starchy-sweet;
• popping;
• waxy;
• pod.

In Russia, dent and flint maize are most widespread, as they are well suited for growing for grain and silage.

Pod maize

Pod maize (Zea mays L., tunicata) is characterized by a loose structure of cobs and strongly developed bracts of female flowers, tightly covering the caryopsis. It has no production significance.

Biological features

Vegetation

Vegetation phases:

• seedling emergence;
• leaf formation;
• stem elongation;
• tasseling;
• flowering;
• milk stage;
• wax ripeness;
• full ripeness.

The duration of phases depends on the variety, weather conditions, and agrotechnology.

In the middle belt of the European part of the country, for widespread hybrids and varieties, the period from seedling emergence to flowering is 50–55 days; from fertilization to grain ripening — 35–60 days.

In the first 25–30 days after seedling emergence, before the formation of the first aboveground stem node, plants develop slowly, which must be taken into account when building a plant protection system against weeds. The most intensive growth occurs in the period from the beginning of internode growth to tasseling. In this period, under favorable conditions, growth rates reach 10–12 cm/day. Growth in height stops after the flowering phase.

The critical growth phases of maize that determine yield are:

• the 2–3 leaf phase, when differentiation of the rudimentary stem occurs;
• the 6–7 leaf phase, at which the size of the cob is determined.

Important development phases also include:

• tassel formation, which occurs in early-ripening varieties in the 4–7 leaf phase, mid-ripening — 5–8 leaf, late-ripening — 7–11 leaf;
• cob formation, which occurs in early-ripening varieties in the 7–11 leaf phase, mid-ripening — 8–12 leaf, late-ripening — 11–16 leaf.

During 10 days before tasseling and 20 days after the end of flowering (that is, in the critical period of water consumption), maize accumulates up to 75% of organic mass. Drought, excess soil moisture, and lack of mineral nutrition during flowering and fertilization reduce fertilization and grain set of cobs.

The maximum amount of raw mass is accumulated by plants in the milk stage; dry matter — at the end of the wax ripeness phase of grain. To obtain a high grain yield, crops must form a total leaf surface area of at least 40–50 thousand m²/ha; for green mass — at least 60–70 thousand m²/ha.

A relationship has been established between the length of the growing season and the number of leaves on one plant (correlation coefficient 0.82–0.99), and between the length of the growing season and grain yield (0.70) (Volodarsky, 1975).

The growing season of maize lasts from 70 to 180 days. According to the length of the growing season, the following are distinguished:

• early-ripening with a duration from seedling emergence to full grain ripening of 80–90 days, number of leaves on the main stem 10–12;
• mid-early — 90–100 days, number of leaves 12–14;
• mid-ripening — 100–115 days, number of leaves 14–16;
• mid-late — 115–130 days, number of leaves 16–18;
• late-ripening — 130–150 days, number of leaves 18–20;
• very late-ripening — more than 150 days, number of leaves more than 20.

Crop rotation

In field crop rotations, maize is usually placed after winter cereals, grain legumes, and also after potato, sugar beet, gourds, and other row crops; also, when harvested for silage — in fallow. In areas of insufficient moisture, maize is not placed after sunflower and sugar beet, since they strongly dry the soil to a great depth. In addition, sunflower heavily infests crops with volunteers, and when placed after beet, the availability of phosphates decreases.

Millet is considered an unfavorable predecessor of maize, since they share a common pest — the corn borer.

In Siberia, a good predecessor of maize is spring wheat following a layer or turnover of perennial grass layer.

The predecessor is especially significant in dry years.

At the Zherebkovskaya Experimental Station of the VNII of Maize of Odessa Oblast, Ukraine, on average over 7 years the maize grain yield was after peas 62.1 c/ha, after winter wheat 59.9 c/ha, after maize 54 c/ha, after sugar beet 51.3 c/ha.

According to data of the Voronezh Experimental Station of the VNII of Maize over three years, maize grain yield after grain legumes was 36.6 c/ha, after maize for silage — 35.3 c/ha, after winter wheat — 32.8 c/ha, after sugar beet — 26.1 c/ha. In experiments of the Krasnograd Experimental Station of the VNII of Maize of Kharkov Oblast, Ukraine, on chernozem soil on average over ten years, the maximum yield of 34.2–35.1 c/ha was after winter wheat and vetch. After maize for grain and silage, grain harvest was 31.3 c/ha and 32.3 c/ha; after sugar beet — 2.0–2.9 c/ha less than after winter crops and vetch.

According to data of the Don NIIAKh, in Rostov Oblast the best predecessors are grain legumes and winter wheat; after them the soil is treated as a semi-fallow. In southern regions, maize can be cultivated as a stubble crop, obtaining two harvests per year and harvesting in the milk-wax ripeness phase. Aftercut crops after fodder crops for green fodder and silage are also widespread.

Maize, especially grown for silage, is a good predecessor for many crops, including winter wheat and spring cereals.

If crop rotations need to be saturated with maize, it can be cultivated repeatedly. High yields are possible provided the fertilizer system and a full agrotechnical complex are observed. Yield decreases with insufficient fertilizer application and unsatisfactory plant protection from pests, diseases, and weeds.

According to experimental data, under conditions of the central steppe of Ukraine, maize can be grown continuously with periodic interruption in specialized maize crop rotations with short rotation:

• 1, 2, 3 — maize; 4 — peas;
• 1, 2 — maize; 3 — maize for silage; 4 — winter wheat.

These crop rotations are convenient for farms with dairy and meat (beef or pork) specialization.

In many regions of Russia, maize-alfalfa crop rotations are effective, in which maize and alfalfa alternate every 4–5 years, while obtaining 7–10 thousand/ha feed units.

In the Non-Black Earth zone, maize can be grown in outlet fields of crop rotations, on so-called permanent plots, while obtaining stable green mass yields over years. Cultivation in outlet fields is especially advisable on farms where there is little fertile land and fields differ in fertility and are remote from farms. This is important in areas with poor soils, where it is effective to place maize in river floodplains and other fertile plots. Placing it on permanent plots near farms eliminates the need to transport fertilizers and harvest over long distances.

The ability of maize to tolerate continuous crops is explained by the large mass of organic residues that remain annually in the field, small accumulation of blister smut pathogens in the soil, and reduced weediness of repeated crops as a result of interrow cultivation and herbicide application. Good results in the Non-Black Earth zone are also obtained when maize is included in fodder crop rotations with short rotation and alternated with potato, root crops, and vegetable crops.

According to a large body of experimental material and the experience of advanced farms, the best predecessors of maize in different soil-climatic zones are considered to be:

• in the Non-Black Earth zone (for silage) — winter crops, potato, root crops, and crops under which sufficient fertilizer is applied, layer and turnover of perennial grass layer; also permanent plots (outlet fields);
• in the Central Black Earth zone — grain legumes, winter cereals, potato; in areas of sufficient moisture also sugar beet;
• in the Southeast of Russia — grain legumes, vegetable and gourd crops, winter and spring cereals;
• in the North Caucasus, Ukraine, and Moldova — winter cereals, grain legumes and gourd crops; in areas of sufficient moisture also root and tuber crops;
• in Transcaucasia — grain legumes and cereal crops;
• in Central Asian countries and southern Kazakhstan — grain legumes and cereal crops, cotton.

Fertilizer system

During the growing season, maize consumes a large amount of nutrients. To create 1 t of grain and the corresponding amount of leaf-stem mass, it consumes on average 24–30 kg of nitrogen, 10–12 kg of phosphorus, and 25–30 kg of potassium. At a yield of 5–6 t/ha of grain or 50–60 t/ha of green mass, about 150–180 kg N, 60–70 P₂O₅, and 160–190 kg K₂O are absorbed from the soil. More than half of the nutrients are assimilated from the soil in the second half of the growing season, therefore top dressing in summer and the wide-row sowing method, which allows fertilizers to be applied during the growing season, are important.

The maize fertilizer system includes:

• basic fertilizer, applied in autumn or spring before sowing;
• pre-sowing (local);
• top dressing during the growing season.

Micronutrients

Micronutrients also help increase maize yield. Maize plants often experience deficiency of boron, manganese, and zinc.

Boron fertilizers are used on sod-podzolic, sod-gley, red soils, humus-carbonate, leached chernozem, serozem, and bog soils. Manganese fertilizers are applied on slightly leached chernozem, gray forest, solonetzic, and chestnut soils. Zinc fertilizers are used on sod-carbonate, chestnut, brown, serozem, serozem-meadow, neutral sandy, and chernozem soils.

Boron deficiency is especially pronounced on limed soils. Boron fertilizers are applied to the soil in the form of boron-enriched superphosphate, boron-magnesium fertilizers, or boric acid; seeds are treated or foliar top dressing is carried out. Application of boron fertilizers increases maize grain yield by 4–7 c/ha and green mass by 4–8 t/ha. As manganese fertilizers, manganese-enriched superphosphate or manganese sulfate can be used. On acidic and waterlogged soils, excess manganese may be noted. Increased doses of mineral fertilizers, especially phosphorus and calcium, lead to an increase in maize demand for zinc, which is applied in the form of zinc sulfate (8–15 kg/ha) or polymicronutrient fertilizer. Copper fertilizers are used on peat soils. Application of a full dose of organic fertilizer in most cases eliminates micronutrient deficiency.

Maize nutrition diagnostics

Main page: Maize nutrition diagnostics

Soil tillage system

Sowing

Combined crops with legumes and other crops

When cultivating maize for silage and green fodder, combined crops with leguminous crops have become widespread. In the south of Russia the best components are tall soybean; in the Non-Black Earth zone — lupine and fodder beans.

Sowing maize with lupine is carried out by the wide-row method with 70 cm interrows at a plant density of 60–80 thousand/ha (seeding rate 30–40 kg/ha). Mixtures of maize with fodder lupine — 40–80 kg/ha, or 265–530 thousand/ha plants.

Good results have been shown by combined crops of maize with white fodder lupine at a ratio of maize to lupine of 2:4 and by interplanting lupine into maize during interrow cultivation.

To increase the harvest of maize for silage and improve its technological properties in the south of Russia, combined crops of maize with sunflower and sorghum are practiced.

Mixed crops of maize for silage and sorghum allow increasing the green mass yield by 3–5 t/ha and lengthening the ensiling period by 10–15 days. According to data of the Erastovskaya Experimental Station (Dnipropetrovsk Oblast, Ukraine), sowing maize alone gave 13.5 t/ha of green mass; combined sowing of two rows of maize and one row of sorghum — 16.0 t/ha.

Based on accumulated experience, the following mixtures of maize with other crops are recommended depending on the zones:

• European part of Russia, Belarus, Polesie of Ukraine: maize with fodder lupine, maize with field pea or vetch, maize with serradella;
• Krasnodar and Stavropol Krais and Rostov Oblast: maize with soybean for silage, maize with pumpkin, maize with squash, maize with sorghum, maize with Sudan grass;
• Ukraine and Moldova: maize with beans and soybean, maize with pumpkin and squash, maize with sorghum and Sudan grass, maize with peas and vetch (in western Ukraine), maize with chickpea in the steppe part;
• Transcaucasia: maize with beans for grain, maize with soybean for grain and silage, maize with pumpkin.

Sowing of compacting crops is carried out either simultaneously with maize or after the first interrow cultivation.

Crop care

If necessary, rolling is carried out after sowing.

In experiments of the Chernigov Agricultural Experimental Station, rolling after sowing with water-filled rollers increased grain yield by 9.5 c/ha with a control yield of 50.4 c/ha. Field germination increased from 71 to 80%. In studies of the Kharkov Agricultural Institute, it was shown that uneven crops lead to a decrease in grain yield by 10–12% (Kuleshov).

To destroy the forming soil crust and destroy germinating weeds, on the 4th–5th day after sowing or 4–5 days before seedling emergence, harrowing is performed, for example, with BZSS-1 harrows. The harrow teeth should penetrate the soil 1–2 cm less than the sowing depth. Harrowing is carried out across the sowing direction. After seedling emergence, the formed crust is destroyed with rotary hoes.

In the initial period, maize development is slow, so there is a threat of its crops being smothered by fast-growing weeds; to control them, crops are harrowed by seedlings in the 3–6 leaf phase, when the growth point sensitive to mechanical damage is in the soil and protected by tightly folded leaflets. Harrowing destroys 70–85% of weed seedlings. To reduce damage to maize seedlings during harrowing, thorough pre-sowing soil treatment is carried out. In the initial phases of growth, plants often die due to being pulled out by harrow teeth. When 2–3 leaves form, plant death occurs due to being covered with soil. When treated in the 5–6 leaf phase, the harrow cannot pull out plants or cover them with soil.

Harrowing is carried out in the middle of the day with light, medium, or rotary hoes when plant turgor is weakened to reduce damage to crops.

In the case of good pre-sowing treatment and the use of soil herbicides, 1–2 interrow cultivations are carried out. If thinning is necessary, it is performed in the 3–4 leaf phase.

In precision crops, 2–3 interrow cultivations are carried out in a timely manner: the first — in the 3–5 leaf phase, the second — two weeks after the first, the third — when plants are 60–70 cm tall. The depth of cultivation is gradually reduced.

After the appearance of 6–7 leaves, nodal roots begin to form, lying at a depth of 6–8 cm. Damage to the root system of young plants leads to delayed development. In the zone of sufficient moisture, damaged roots recover relatively quickly, whereas in arid conditions regeneration occurs slowly, and yield decreases. The depth of cultivation and the width of the protection zone are established depending on weediness and soil compaction of interrows and the development of the root system.

During interrow cultivation, protection zones are simultaneously treated with weeding harrows or rotary hoes with needle disks. During loosening they crumble and level the soil surface and destroy weeds. During the last cultivation, remaining weeds in the protection zones are covered with a layer of soil using hiller shares. As a rule, the depth of the first cultivation is up to 10–12 cm, subsequently reduced to 4–7 cm. During the first cultivation, the width of protection zones is 10–15 cm; during subsequent ones — 15–25 cm. Weeding harrows allow destruction of 80–85% of annual weed seedlings; rotary needle disks — 70–75%.

Effective arrangement of cultivator working parts depending on the location of roots in the soil. At the same time, the loosening depth is increased gradually, as the distance from the row to the center of the interrow increases. Thus, the loosening depth in the 3–4 leaf phase at the edges of the interrow is 6–7 cm, and in the center — 10–12 cm; in the 7–8 leaf phase, respectively 5–6 cm and 12–14 cm; in the 10–12 leaf phase — 4–5 cm and 7–8 cm, respectively.

To control blister smut, root rots, fusarium, and cob mold, the preparation Bayleton (250 g/kg) is used.

To control leaf aphid and leafhoppers, the preparation Fufanon (570 g/l) is used; against corn borer — the preparation Decis (25 g/l); against cotton bollworm — the preparation Arrivo (250 g/l).

In maize crops the following herbicides are used:

• Bazagran (480 g/l) — against annual dicotyledons, including those resistant to 2,4-D; spraying in the 3–5 leaf phase of the crop;
• Banvel (480 g/l) — against annual dicotyledons, including those resistant to 2,4-D, some perennial dicotyledons (thistle); used separately or in mixtures with 2,4-D; spraying in the tillering phase, 2–4 leaves in annual and 15 cm height in perennial weeds;
• Bromotril (225 g/l) — annual dicotyledons, including those resistant to 2,4-D; spraying in the 3–5 leaf phase of the crop;
• Dialen (342 + 34.2 g/l) and Dialen Super (344 + 120 g/l) — annual dicotyledons, including those resistant to 2,4-D, as well as sow thistle species; spraying in the 3–5 leaf phase of the crop;
• Lontrel-300 (300 g/l) — against sow thistle, chamomile, and knotweed species; spraying in the 3–5 leaf phase of the crop;
• Luvaram (610 g/l) — annual dicotyledons; spraying in the 3–5 leaf phase of the crop.

Herbicides

Common weeds in maize crops include: annual — field mustard (Sinapis arvensis), amaranth (Amaranthus sp.), white goosefoot (Chenopodium album), common barnyardgrass (Echinochloa crus-galli), foxtail (Setaria sp.) and perennial — field thistle (Cirsium arvense), field sow thistle (Sonchus arvensis), field bindweed (Convolvulus arvensis).

Agrotechnical methods do not always allow destroying weeds in rows. To control them, soil and post-emergence herbicides are used. Highly effective herbicides are an integral element of zonal industrial maize production technologies. Herbicides are selected taking into account the type of field weediness, zonal cultivation characteristics, and chemical and phytotoxic properties of preparations. The use of chemical control agents allows reducing the number of cultivations.

Soil-acting herbicides used in maize crops include: Eradican 6E (4–8 l/ha), ageлон (4–6 kg/ha), atrazine (3–8 kg/ha), simazine (1.9–7.5 kg/ha), Prim-extra* (4–6 kg/ha). Treatment with Eradican 6E is carried out as spraying with immediate incorporation into the soil. Herbicides are applied taking into account the moisture of the sowing soil layer: in areas of insufficient moisture — during the first or pre-sowing cultivation; in areas with sufficient moisture — in bands before or after (before pre-emergence harrowing) sowing. Atrazine, simazine, ageлон, and nitazin have a negative aftereffect on sensitive crops such as wheat, barley, oats, and sunflower for 1–2 years. For this reason, the preparations are used on fields where maize is cultivated in repeated crops for 2–3 years in a row or where crops resistant to these herbicides are sown after it, for example, millet, sorghum, peas, fodder beans, and potato.

If weeds cannot be completely suppressed by soil (basic) herbicides, and their seedlings or shoots appear in crops, post-emergence (rescue) preparations are used. Optimal consumption rates of post-emergence herbicides: 2,4-D amine salt — 1.5–2.5 kg/ha, Dialen — 1.9–3 kg/ha, Mayazin (Zeapos-10) — 5.3–13.3 kg/ha, Oleogezaprim — 40% mineral-oil suspension — 2–5 kg/ha. Treatment with them is carried out in the 3–6 leaf phase of maize. The use of herbicide mixtures is effective, due to which the spectrum of action expands, phytotoxicity in the soil decreases, and the total consumption of preparations is reduced.

When using basic herbicides based on atrazine (ageлон, Primextra, mixtures of Eradican with atrazine) in maize crops cultivated in crop rotation, post-emergence treatments with rescue herbicides based on an oil solution of atrazine (Mayazin, Oleogezaprim) are not carried out. This is because it strengthens their negative effect on sensitive crops. Such fields are treated with 2,4-D amine salt or Dialen.

Diseases

Characteristic maize diseases include blister and loose smut, helminthosporiosis, root and stem rots, fusarium, mold of seeds and seedlings, and bacteriosis of cobs.

To control diseases, seed material is dressed, alternation in crop rotation is used, optimal dates for sowing and harvesting are observed, and fertilizers are applied. To prevent the spread of blister and loose smut in seed plots, affected plants are removed before harvesting and subsequently destroyed.

Main bacterial and fungal pathogens of maize diseases:

• Colletotrichum graminicola (anthracnose);
• Pseudomonas syringae, other Pseudomonas spp., Sclerospora graminicola;
• Erwinia sp., Pectobacterium sp. and Pseudomonas sp. (bacterial soft rot);
• Puccinia sorghi (common rust);
• Mycosarcoma maydis, syn. Ustilago maydis (common smut);
• Peronospora spp. and Sclerophthora spp. (downy mildews);
• Sporisorium reilianum (head smut);
• Setosphaeria turcica (northern corn leaf blight);
• Pythium sp. and Fusarium sp. (seed damping off);
• Cochliobolus heterostrophus (southern corn leaf blight);
• Puccinia polysora (southern rust);
• Stenocarpella maydis, Fusarium sp. (stalk rot);
• Pantoea stewartii (Stewart’s bacterial wilt);
• Physopella zeae (tropical rust);
• Mycosphaerella zea-maydis (yellow leaf blight).

The southern leaf blight of maize during the epidemic of 1970–1971 did not become a serious problem in the production of hybrid sweet maize, since the cytoplasmic male sterility (CMS) used differed from the susceptible form used for other maize hybrids.

Viral diseases:

• Cucumber mosaic virus (Cucumber mosaic virus, CMV);
• Maize chlorotic dwarf virus (Maize chlorotic dwarf virus, MCDV);
• Maize dwarf mosaic virus (Maize dwarf mosaic virus, MDMV);
• Maize mosaic virus (Maize mosaic virus, MMV);
• Maize rough dwarf virus (Maize rough dwarf virus, MRDV);
• Maize streak virus (Maize streak virus, MSV);
• Sugarcane mosaic virus (Sugarcane mosaic virus, SCMV).

Virus-like diseases:

• Corn bush stunt (mycoplasma, Corn bush stunt, CBSM);
• Corn stunt (spiroplasma, Corn stunt, CSS);
• Maize wallaby ear (reaction to grasshopper toxin, Maize wallaby ear).

Pests

Characteristic maize pests include cotton bollworm, winter cutworm, stalk (corn) borer, meadow moth, wireworm, false wireworm, Swedish fly, mole cricket, and root and leaf aphids.

To control the stalk borer, low cutting height of stems during harvest, chopping of crop residues, and deep autumn plowing are recommended.

Against winter cutworm, loosening of interrows during the egg-laying period is effective.

Against wireworm, when their number is more than 3–10 individuals/m², chemical control methods are used.

Against Swedish fly, agrotechnical methods are most effective, for example, sowing at optimal dates and fertilizer application. Edge treatments with chemical preparations are also carried out.

Pest nematodes include stem and bulb nematodes (Ditylenchus spp.) and root nematodes (Paratrichodorus spp). In addition, sweet maize is attacked by lesion, dagger, lance, and needle nematodes.

Insect pests include the following:

• Spodoptera frugiperda (fall armyworm);
• Mythimna unipuncta (armyworms);
• Blissus leucopterus (chinch bug);
• Helicoverpa zea (corn earworm);
• Rhopalosiphum maidis (corn leaf aphid);
• Agrotis spp. and Feltia spp. (cutworms);
• Ostrinia nubilalis (European corn borer);
• Systena spp. (flea beetles);
• Melanoplus spp. (grasshoppers);
• Diabrotica spp. (rootworms);
• Delia platura (seed corn maggot);
• Tetranychus urticae (spider mite);
• Papaipema nebris (stalk borer);
• Lygus lineolaris (tarnish plant bug);
• Anaphothrips obscurus (thrips);
• Peridroma saucia (variegated cutworm);
• Melanotus spp. (wireworms).

Maysin, a flavonoid glycoside contained in maize silk, has antibiotic activity against corn earworm larvae; genotypes differ in maysin content in silks.

Harvesting

Maize ripens late and unevenly; cobs are located at different heights; if harvesting is delayed, plants may lean and lodge. The grain in cobs holds firmly; filling stops at grain moisture of 35–40%.

Harvesting maize for grain begins at the beginning of full ripeness and is completed after 10–12 days. To reduce yield losses due to extended harvesting periods, it is advisable to sow several hybrids with different growing season lengths and ripening dates. This allows each hybrid to be harvested at optimal agrotechnical dates — within 10–12 days with a total harvesting duration of 25–30 days.

The following technological schemes for maize harvesting are used:

• special maize combines with simultaneous cleaning of cobs (for all zones of the country);
• the same maize combines with subsequent cleaning of cobs on stationary machines OP-15S, for example, in Polesie and southern oblasts of the Central Black Earth zone;
• self-propelled grain combines with special attachments PPK-4 with feeding only cobs into the thresher for threshing and simultaneous collection of chopped mass (for all zones of the country). For this method, grain harvesters are used, for example, SK-5 “Niva”, “Don-1500” with special attachments.

For harvesting cobs, combines of the KKP-3 and KSKU-6 type are used, separating cobs from stems and collecting chopped leaf-stem mass.

Threshed grain in the last harvesting method is preserved at moisture above 30%, or after processing and drying is stored. This harvesting technology is the most rational in technical and economic indicators. Seed maize for seed purposes is stored in cobs or in grain: cob moisture should be no higher than 16%, grain — no higher than 13%.

The greatest yield of dry mass, protein, and fat collection is achieved when harvesting in the wax ripeness phase of grain. Therefore, it is better to harvest maize for silage in the milk-wax and wax ripeness phase of grain. Vegetative mass and cobs contain much water and sugars, so they ensile well. In regions where these phases do not have time to occur, harvesting is carried out before frosts with silage and forage harvesters of the KSS-2.6, KSK-100, KSKU-75, KS-1.8 “Vikhr” type, which chop the plant mass and load it into transport vehicles. Maize for green fodder begins to be harvested upon reaching a useful yield of green mass. Its consumption by livestock decreases after the tasseling phase.

After additional drying to 14–15%, maize grain can be stored in cobs or threshed. However, under-dried grain quickly becomes bitter.

In regions where maize does not fully ripen, grain can be used in preserved form for feed. For this, at moisture of 32–35%, without drying, it is ground into particles 2–3 mm in size. The trench walls are lined with film, the ground grain is compacted with heavy tractors, then isolated from air access. The trench is filled and covered within 3–5 days. For grinding grain, grinders or crushers are used.

Preservation of pre-ground unhusked maize cobs with grain is also used. The technology for preparing such maize feed was introduced in the 1980s on the “Rossiya” farm of Shebekinsky District, Belgorod Oblast. The technology made it possible to increase the collection of feed units by 30–40% per 1 ha and reduce cost by 35%.

Cultivation features under irrigation

High and stable yields of maize grain and green mass are obtained under irrigated farming. Maize is one of the main fodder crops grown on irrigated plots. Yield can reach 7–10 t/ha of grain and 70–80 t/ha of green mass. According to averaged data over 24 years of the Kabardino-Balkarian Agricultural Experimental Station, irrigation of maize crops against the background of mineral fertilizer application increased yield from 38 to 71 c/ha; against the background of organic and mineral fertilizers — from 40 to 74.1 c/ha.

Wide-row and precision sowing methods facilitate furrow irrigation in interrows.

According to data of the VNII of Maize, in steppe regions of Ukraine, plant water consumption at the same yield reaches 6000 m³/ha. High and at the same time economically profitable yields are noted when, through irrigation, the moisture content of the root-inhabited layer (up to 60–80 cm) is maintained at not less than 70% of the least moisture capacity on light soils and not less than 80% on heavy soils. This is achieved by combining autumn, winter, spring moisture-recharging and vegetative irrigations.

According to data of the Kabardino-Balkarian Agricultural Experimental Station, the effectiveness of maize irrigation on average over 7 years was shown in the following experiments:

• without irrigation — grain yield 44.7 c/ha;
• with moisture-recharging irrigation — yield 52.4 c/ha of grain;
• with moisture-recharging irrigation and 2 vegetative irrigations in the 6–7 leaf and tasseling phases — yield 72.2 c/ha of grain;
• with moisture-recharging irrigation and 3 vegetative irrigations in the 6–7 leaf, tasseling, and grain filling phases — yield 77.4 c/ha of grain;
• irrigation at soil moisture of 80% of least moisture capacity — yield 88.3 c/ha of grain.

Moisture-recharging irrigation and precipitation during the autumn-winter-spring period should ensure moistening of the soil layer to 1.2–2 m at 90–100% of least moisture capacity. The irrigation norm is 1000–2000 m³/ha. Moisture-recharging irrigations are carried out before or after autumn plowing depending on soil dryness. If the soil is insufficiently moistened by atmospheric precipitation and no autumn moisture-recharging irrigation was performed, pre-sowing irrigation is carried out. The rate of pre-sowing irrigation is 300–400 m³/ha of water; if no moisture-recharging irrigation was carried out in autumn, the rate is increased to 800–1500 m³/ha.

Moisture-recharging irrigations contribute to an increase in grain yield by 6–15 c/ha and silage mass by 3–12 t/ha.

In some cases, provocative irrigations of 250–300 m³/ha are used to provoke weed growth with subsequent destruction.

The number of vegetative irrigations depends on the amount of precipitation, irrigation norms, and irrigation technique, for example, furrow or sprinkler. As a rule, their number is from 2 to 5 with a total irrigation norm of 2000–3000 m³/ha of water. To obtain a high yield of grain and green mass, irrigations must be organized so that plants constantly vegetate under optimal moisture conditions and do not experience even short-term water shortages. Temporary waterlogging of the soil is also undesirable for maize.

It is recommended to determine irrigation dates by morphological characteristics, development phases, soil moisture, physiological indicators, and calculation. For example, dates and rates of irrigation are established in the 6–7 leaf, 13–14 leaf, tasseling, grain formation and filling phases, or when soil moisture reserves decrease below 70–80% of least moisture capacity. Usually, both methods give approximately the same results.

When determining dates and rates by development phases, irrigations are set during periods of greatest sensitivity of maize plants to lack of soil moisture. In the south of Kuban, the Central Black Earth zone, the forest-steppe zone of the Volga region, and Ukraine, where 500–600 mm of precipitation falls during the year, one irrigation is required. Additionally, it is advisable to carry out irrigation in the critical period, that is, 10–15 days before tasseling, 600–800 m³/ha of water. In dry years in these regions, as well as in the steppe part of Moldova, Ukraine, the Volga region, the North Caucasus, Transcaucasia, and Central Asian regions, with annual precipitation of 300–500 mm, 2–4 irrigations are carried out at a rate of 600–800 m³/ha of water; the first in the 6–8 leaf phase (during the formation of nodal roots), the second — before tassel emergence, the third — during grain filling. If three irrigations are planned, one is given in the 6–8 leaf phase. In dry years, the fourth irrigation is performed during the milk stage of grain. Schemes can be adjusted depending on weather conditions.

In semi-desert regions with annual precipitation of less than 300 mm, the number of irrigations can increase to 5–7. They are carried out at the beginning and end of the growing season every 15–25 days, and during the critical period — every 10–15 days.

To determine irrigation dates, physiological indicators of plants are also used, for example, cell sap concentration, suction force, osmotic pressure, and degree of stomatal opening.

When establishing irrigation norms, the water-physical properties of the soil, groundwater depth, and irrigation methods are taken into account. On plots with deep groundwater, increased irrigation norms are used — from 800 to 1000 m³/ha of water; with shallow groundwater and sprinkler irrigation — 400–700 m³/ha.

During the USSR period, sprinkler irrigation was used on 83% of all irrigated lands in Moldova, on 74% of irrigated lands in Ukraine, and on 40% of irrigated lands in the RSFSR. In southern Ukraine combined irrigations are used: 1–2 irrigations at a rate of 400–500 m³/ha by sprinkling, subsequent ones — at a rate of 700–800 m³/ha by furrows.

Features of maize cultivation technology under irrigation:

• application of increased fertilizer doses, primarily nitrogen;
• greater plant density than in rainfed crops;
• effective plant protection system against weeds;
• use of varieties and hybrids responsive to irrigation;
• loosening of interrows after irrigation.

Requirements for soil treatment quality on irrigated lands are higher than on non-irrigated lands. For high-quality and effective irrigation, the field after plowing should be leveled, without large center ridges and deep split furrows.

Under irrigation conditions, the limiting factors for yield are only fertilizers and water, so conditions are created for obtaining programmed yields of maize grain and green mass.

Under irrigation conditions, zoned hybrids and varieties of intensive type are used, responsive to irrigation and fertilizer application, capable of accumulating not less than 3.5–5% PAR. For example:

• mid-early hybrids — Pioner 3978M, Kubansky 275M;
• mid-ripening hybrids — Krasnodarsky 440MV, Odessky 59MV, Osetinsky 5TV, Stavropolsky 1MV, Kartuli 9MV;
• mid-late hybrids — Dneprovsky 758TV, Dneprovsky 201, Dneprovsky 85T, Krasnodarsky 303TV;
• late-ripening hybrids — Krasnodarsky 229TV, VIR 156TV, VIR 338TV, Chuysky 47, Iveria 503.

Water often limits the yield of maize green mass in some regions of the Non-Black Earth zone. According to the experience of many farms in the Moscow region, during dry growing periods 1–2 sprinkler irrigations increase green mass yield by 30–40%, reaching 90 t/ha.

Modern maize cultivation technologies

Industrial maize cultivation technology provides for the integrated use of intensive varieties and hybrids, placement of crops after the best predecessors, high-quality soil treatment, timely and effective weed control using highly effective rapidly decomposing herbicides, application of optimal fertilizer doses, performance of work with modern high-productivity agricultural machinery, introduction of progressive forms of labor organization and payment, and sowing of calibrated first-class seeds. Under industrial cultivation technology, individual field operations are combined, manual weeding is eliminated, the number of interrow cultivations and the total number of operations are reduced, and labor costs for production are reduced by 1.5–2 times.

Volgograd Agricultural Institute, MSKhA named after K. A. Timiryazev, the Southern Research Institute of Hydraulic Engineering and Land Reclamation, the VNII of Maize, the Ukrainian Research Institute of Irrigated Agriculture, and other experimental institutions have developed technologies for programmed maize cultivation that allow obtaining grain yields of up to 15 t/ha and green mass up to 150 t/ha without manual labor. These technologies, especially under irrigated farming, allow obtaining stable high maize yields with good economic indicators.

Resource-saving intensive technology for cultivating maize for grain

Experiments conducted by the Department of Agriculture and Plant Growing of the State University of Land Use Planning (Niklyaev V. S., 1995–1998) in Belgorod Oblast on an area of 130–213 ha, using resource-saving cultivation technologies, obtained a maize yield of 33–40 c/ha of grain. On an area of 78 ha the yield was 44 c/ha. Maize crops were placed after winter wheat following clean fallow. After wheat harvest, disk disking was carried out to a depth of 8–10 cm, plowing to a depth of 25–27 cm with observance of quality requirements. In spring — harrowing of autumn plowland when the soil was in a state of physical ripeness, pre-sowing cultivation to 6–8 cm. Such treatment promoted accumulation and preservation of moisture and nutrients in the soil, improved the air regime, increased soil biological activity, and reduced field weediness, numbers of pests, and disease pathogens. The field prepared for sowing was leveled with a dense seedbed; in the treated layer the content of clods 1–5 cm in size was not less than 80%, and clods larger than 10 cm were absent.

In the experiments, fertilizers were applied under pre-sowing cultivation at 150 kg/ha and at sowing 80–100 kg/ha of nitrophoska. Organic fertilizers were applied under the predecessor.

The plant protection system included application of the herbicide Harnes at a dose of 3 kg/ha during pre-sowing cultivation. In the 3–5 leaf phase, treatment was carried out with the amine salt of 2,4-D at 2 kg/ha.

For sowing, dressed, calibrated seeds of high reproductions, first class, of hybrids Dnepropetrovsky 203MV, BEMO-182, Kulon MV were used.

Sowing began when the soil at the seed placement depth warmed to 10–12 °C, usually in late April — first decade of May. Sowing was carried out in compressed periods by the flow method, precision method with 70 cm interrows. Placement depth 4–6 cm into the moist layer. Seeding rate 60–80 thousand/ha of germinating seeds. Calculated plant density 50–60 thousand/ha plants.

Crop care consisted of post-emergence harrowing in the 3–5 leaf phase and 2–3 interrow cultivations depending on crop weediness and soil compaction. The first interrow cultivation was carried out to a depth of 6–8 cm, the second — 5–6 cm with deepening toward the middle of the interrow to 8–10 cm, the third — hilling. For hilling, hiller shares KRN-52-53 were used.

Grain harvesting was carried out in the full ripeness phase with a Don-1500 combine equipped with KMD-6.

Energy costs of the given technology per 1 c of grain are 6–8% less compared with traditional (they differ somewhat by years and hybrids).

Resource-saving intensive technology for cultivating maize for silage

Resource-saving intensive technology for cultivating maize for silage was tested in experiments of the Department of Agriculture and Plant Growing of the State University of Land Use Planning (Niklyaev V. S., 1997–1998) in Moscow Oblast on an area of 145 ha and 100 ha; green mass yield was 36 t/ha and 40 t/ha. Nutritive value was 0.24 and 0.26 feed units; crude protein collection — 7.2 c/ha and 8 c/ha.

This technology is based on rational methods of soil treatment, sowing of early-ripening and mid-early hybrids, optimal rates of fertilizers and herbicides, improvement of the territorial structure of feed production, and advanced training of specialists.

Technological scheme:

• application of manure once every 4–5 years at 40–50 t/ha;
• autumn plowing to a depth of 20–22 cm;
• closing of moisture in early spring and leveling of the soil surface;
• cultivation to a depth of 14–16 cm;
• application under pre-sowing cultivation of 200 kg/ha of ammonium nitrate and potassium chloride;
• pre-sowing cultivation to a depth of 8–10 cm;
• sowing by wide-row precision method at optimal dates (until May 15), seed placement depth 5–6 cm, seeding rate for early-ripening hybrids 110–120 thousand/ha of germinating seeds, for mid-early — 90–100 thousand/ha of germinating seeds;
• row application at sowing of 100 kg/ha of nitrophoska;
• application at sowing of the herbicide Harnes 3 kg/ha or Eradican 8 l/ha;
• treatment in the 3–5 leaf phase with the herbicide Dialen 2 kg/ha;
• pre-emergence harrowing;
• in the 8–10 leaf phase — interrow cultivation to a depth of 6–8 cm with simultaneous application of 80 kg/ha of ammonium nitrate;
• harvesting by the group corral method in late August–early September in the milk-wax and wax ripeness phase. Early-ripening hybrids are harvested first; cutting height not more than 10–12 cm;
• placing green mass in trenches within no more than 3–4 days with compaction;
• covering the compacted mass with polyethylene film and soil.

Early-ripening hybrids: Nart 170 SV, Bemo 182 SV. Mid-early — Kollektivny 244 MV.

Reduction of energy costs with the resource-saving technology of maize cultivation for silage compared with traditional was 10–12.5%.

Astrakhan technology

The Astrakhan irrigation technology, developed for vegetable crops, has proven itself well. It consists of cutting guide slits before sowing, along which special knives move during sowing and interrow cultivation, preventing displacement of units. This allows work at increased speeds and reduces cutting of maize plants. Simultaneously with cutting slits, herbicides can be applied in bands under the rows.

Varieties

In maize, the heterosis effect is widely used, manifested in first-generation hybrids from crossing different genotypes. The effect is expressed in stronger growth and higher viability of hybrids compared with parental forms. Hybrid seeds are obtained by pollinating one variety or line with pollen of another variety, simple hybrid, or line. A line is the progeny of one plant forcibly self-pollinated for 7–12 generations. Three types of hybrids are distinguished: intervarietal, varietal-linear, and interlinear. Interlinear hybrids can be:

• simple, that is, obtained from crossing two self-pollinated lines;
• three-line, obtained from crossing an interlinear hybrid with a self-pollinated line;
• double, obtained from crossing two simple hybrids;
• five-line, obtained from crossing a three-line and a simple hybrid.

Widespread hybrids.

VIR 42MV — double interlinear hybrid. Obtained by the Kuban Experimental Station of VIR. Stem height 2–2.5 m. Cob mass 200–230 g. Grain yellow, dent, 1000-grain mass about 250 g. Mid-ripening, demanding of heat, resistant to lodging and fungal diseases. Widely zoned.

VIR 156TV — double interlinear hybrid. Obtained by the Kuban Experimental Station of VIR. Plant height up to 3 m. Resistant to lodging. Cob very large. Grain yellow, dent. 1000-grain mass 300–350 g. Late-ripening. Zoned in the North Caucasus and Transcaucasia, Central Asia, southern Ukraine, and Moldova.

Krasnodarsky 5TV — double interlinear hybrid. Obtained by the Krasnodar NIIAKh. Resistant to lodging. Grain yellow, dent. 1000-grain mass 220–300 g. Late-ripening. Zoned in Georgia, Azerbaijan, Kyrgyzstan, Tajikistan, and Turkmenistan.

Bukovinsky 2TV — varietal-linear hybrid. Obtained by the Chernivtsi Agricultural Experimental Station. Average plant height 1.5 m. Grain yellow, semi-flint. 1000-grain mass 200–250 g. Early-ripening. Zoned in the Central Black Earth zone, Volga region, Altai Krai, Siberia, Far East, and Kazakhstan.

Bukovinsky 3TV — varietal-linear hybrid. Obtained by the Chernivtsi Agricultural Experimental Station. Plant height 1.7–2.2 m. Resistant to lodging. Cob mass about 250 g. Grain yellow, semi-flint. 1000-grain mass 300–360 g. Mid-early. Zoned in the Central Black Earth and Non-Black Earth zones, Siberia, Far East, North Caucasus, as well as Belarus, the Baltics, Ukraine, and Kazakhstan.

Krasnodarsky 436MV — double interlinear hybrid. Obtained by the Krasnodar NIIAKh. Plant height up to 2.4 m. Grain yellow, dent. Cob relatively large. The hybrid is resistant to lodging, responsive to moisture, relatively drought-resistant, of grain direction. Zoned in Krasnodar Krai of Russia, Dnipropetrovsk and Zaporizhzhia Oblasts of Ukraine.

Dneprovsky 247MV — varietal-linear hybrid. Obtained by the VNII of Maize. Plant height 2.1–2.4 m. Prone to tillering, moderately resistant to lodging. Cobs large 18–24 cm. Grain yellow, flint. 1000-grain mass 260–350 g. Mid-ripening. Cold-resistant, fast initial growth. Tolerates short spring frosts. Responsive to irrigation. Gives high yields of grain and green mass in different natural-climatic zones of the country. Widely zoned in Russia, Belarus, Forest-Steppe and Polesie of Ukraine, and the Baltics.

Dneprovsky 270MV — three-line hybrid. Bred by the VNII of Maize. Plant height 2.0–2.1 m. Up to 16–18 leaves on the main stem. Mid-early. Cob mass 270–290 g. 1000-grain mass 255–320 g. Grain yellow, flint-dent. Weakly affected by blister smut. Zoned in Kirovohrad Oblast of Ukraine.

At the end of the last century there was increased interest in the USSR and abroad in simple interlinear hybrids as more heterotic. These hybrids exceed widespread varietal-linear and double interlinear hybrids in grain and green mass yield by 10–20%. In addition to greater productivity and less complex seed production, simple hybrids are distinguished by uniformity of a number of traits important for mechanization of cultivation and harvesting, for example, cob attachment height, lodging, stem brittleness, and resistance of cobs to drooping during overstanding. The advantage of simple hybrids over double ones is especially pronounced under irrigation.

Krasnodarsky 303TV — productive mid-late simple hybrid. Created by the Krasnodar NIIAKh. Plant with a strong stem, height up to 2.3–2.4 m. Number of leaves 17–18. Cob large, cylindrical, thick. Grain yellow, dent, thin, relatively small. 1000-grain mass 240–250 g. Ripens 4–6 days later than the double hybrid VIR 42, but the increase in grain collection is 5–15 c/ha, green mass — by 84–115 c/ha. Especially productive under irrigation. Under these conditions, when harvested for grain, stems and leaves remain green and succulent, suitable for ensiling. Less drought-resistant than VIR 42. Relatively resistant to blister smut; resistance to bacteriosis and fusarium is medium. Zoned in Krasnodar Krai and Kabardino-Balkaria, as well as Moldova, Dnipropetrovsk, Odesa, Donetsk, Zaporizhzhia, and Kirovohrad Oblasts of Ukraine.

Kollektivny 150TV — simple hybrid. Obtained jointly by the NII of the Southeast, the Kuban Experimental Station of VIR, the Kuibyshev NIIAKh, the Kinel Experimental Station of the Kuibyshev Agricultural Institute, the Siberian NIIAKh, and the Ukrainian Institute of Molecular Biology and Genetics. Plant height 2.2–2.4 m. Grain yellow or white, dent. Early-ripening. Resistant to lodging. Zoned for grain and silage in Luhansk Oblast.

Significant successes have been achieved in breeding aimed at increasing the content of essential amino acids in grain, primarily lysine. Hybrids Krasnodarsky 436MV, Krasnodarsky 303L, Moldavsky 423L, Krasnodarsky 333L, and Hercules L have been converted to a high-lysine basis.

Hybrids with high lysine content were obtained on the basis of mutant maize forms discovered in 1963 with high lysine content — Opaque 2 and Floury 2, which have a dull matte endosperm of mealy consistency. The grain protein of these hybrids contains 3.8–5.2% lysine, 1.0–1.2% tryptophan, whereas in the grain of ordinary maize with horny endosperm it contains respectively 2.6–3.2% lysine and 0.7–0.8%. The average protein content in the grain of hybrid Krasnodarsky 303L is 9.6–10.6%. In the protein — 4.5% lysine, or 50% more than in the standard.

High-lysine maize allows saving more than 15–20% of high-protein feeds by reducing feed and protein costs per unit of livestock product.

Besides breeding for improved grain quality and green mass of maize (low-lignin forms), yield, resistance to lodging, diseases, and pests, breeding is conducted toward increasing drought resistance, cold resistance, and development of short-stemmed, multi-cob plants. Hybrids with vertical (erectophile) leaf arrangement, less responsive to shading when crops are thickened, are promising.

Under production conditions the following varieties are grown.

Odesskaya 10. Variety bred by VSGI. Very late-ripening, tall, resistant to lodging. Grain yellow, dent. 1000-grain mass 250–300 g. Zoned in Stavropol Krai, a number of oblasts of the Central Black Earth and Non-Black Earth (for silage) zones, the Chechen Republic and Ingushetia, as well as in Ukraine.

Sterling. Variety introduced from the USA. Tall, lodges heavily. Grain white, dent. 1000-grain mass about 300 g. Mid-late. Zoned in almost all maize growing zones.

It is advisable to cultivate several hybrids and varieties of maize with different ripening dates. This allows more effective distribution of sowing and harvesting dates, use of the group method of combine operation, manage with fewer machines, and obtain more stable yields.

List of sources

1. Vavilov P. P., Gritsenko V. V., Kuznetsov V. S. et al. (1986). Plant Growing. Edited by Vavilov P. P. 5th ed., revised and enlarged. Moscow: Agropromizdat.
2. Kolomeichenko V. V. (2007). Plant Growing/Textbook. Moscow: Agrobiznestsentr.
3. Niklyaev V. S. (2000). Fundamentals of Agricultural Production Technology. Agriculture and Plant Growing. Moscow: “Bylina”.
4. Rubatzky, Vincent E., Yamaguchi, Mas. (1997). World vegetables: principles, production, and nutritive values. 2nd ed.