Corn is a cereal crop of high productivity and universal value. It is grown for grain, flour and cereals, as feed for domestic animals and poultry, and finally, for the consumption of young cobs.
To grow corn properly and get a rich harvest, follow the tips below. The article describes in detail the methods of growing corn (sowing in open ground and through seedlings), describes the stages of preparing seeds and soil for sowing, and provides a detailed overview of the varieties of corn that are best suited for growing at home.
Planting and caring for corn
Seeds to produce cobs are planted in pre-weed-free, fertilized and warm soil. Direct sowing is preceded by loosening the designated area.
Note: The seed itself is also subject to preliminary preparation: the grains are heated and soaked until roots appear.
The crop can be placed on the site either in rows or using the square-cluster method. When planting cereals in rows, you should place 3-4 grains in each designated hole, keeping a distance of about 30 cm between plants in the row. In this case, the row spacing is 60 cm. Subsequently, the crops are thinned out, leaving two sprouts in each nest. It should be remembered that corn is a monoecious plant, so it needs to create conditions for cross-pollination. For this purpose, it is advisable to plant the crop in several rows.
Preparing corn grains for sowing
Before planting grains, they must be prepared:
- First, a careful selection is made; preference should be given to the largest seeds; they should not be damaged.
- Next is the germination test. Selected specimens are placed in a 5% saline solution for approximately 5 minutes. Some grains will sink to the bottom; they are the most suitable.
- Next comes etching. It is necessary to protect against diseases. To do this, take a special solution - powdered pesticide, hydrogen peroxide or a weak solution of potassium permanganate. Afterwards, you need to disinfect the seeds by alternately immersing them first in hot water (no more than +50 °C), then in cold water. No more than 20 minutes.
Corn varieties and hybrids
Corn varieties differ in color, taste, size and ripening period. Sugar is the most popular for personal consumption. Most often, the choice falls on early species and hybrids.
Early ripening ripens in 55 - 70 days, mid-early - within 70 - 85 days, and late - in 85 days. There are also regular, sweet and sugar hybrids depending on the level of sugar in the grains.
The most popular varieties and hybrids (Figure 1):
- Spirit is a prominent representative of sweet corn. The grains are bright yellow, the taste is delicately sweet. When grown as seedlings, it produces a high yield in two months.
- Dobrynya is an unpretentious early hybrid that is resistant to various diseases. Large ears of pleasant taste can be consumed within 70 days after sowing.
- Gourmand 121 is a high-yielding variety that is resistant to diseases. The grains are juicy, pleasant to taste, and suitable for canning and freezing.
- Andens - forms two ears with yellow grains. The fruits are suitable for consumption both fresh and canned.
- Ice nectar is a representative of late varieties. Brings rich harvests. Has good taste.
- Early Golden 401 is a low-growing variety that is disease resistant. The pleasant taste of the grains allows you to use corn both at the stage of milk ripeness and for winter harvesting.
- Hopi - has an unusual color (from light gray to almost black) and a nutty flavor. One cob can combine different shades. Has antioxidant properties. It is also used in cosmetology.
Figure 1. Popular varieties of sweet corn: 1 - Spirit, 2 - Dobrynya, 3 - Lakomka, 4 - Andens, 5 - Ice Nectar, 6 - Early Golden, 7 - Hopi Recently,
cereal hybrids have become increasingly popular. They are bred to increase productivity by crossing different genotypes. Among the most popular are:
- Early - Dneprovsky 172 MV, Krasnodar 436 MV;
- Medium - Frame 443 SV, Krasnodar 303 TV.
Corn growing technology
06/01/2017 High corn yields can be obtained only if a set of agrotechnical techniques is used, taking into account the requirements of plants during certain periods of their growth and development. This requires deep knowledge of the biological properties and environmental requirements of the crop. The qualified application of a particular cultivation technology involves taking into account soil and climatic characteristics, which makes it possible to make full use of favorable conditions and weaken or completely eliminate the influence of unfavorable environmental factors.
Influence of environmental factors on plant growth and development
One of the main features of corn is the ability to make full use of favorable conditions for growth and development and produce very high yields, generously paying labor. At the same time, corn places increased demands on heat, moisture, nutrients and other environmental factors.
To ensure normal growth and development of corn, it is necessary to follow the correct agrotechnical methods for its cultivation in relation to a specific soil and climatic zone, making full use of the existing favorable conditions.
Soil requirements
Corn develops many fibrous roots, so it requires loose, well-permeable soils. The best soils for cultivating corn are deep chernozems, dark gray loams, and river floodplain soils with well-permeable subsoil, where its roots can easily penetrate. Corn grows well on sandy loam and even sandy soils if sufficient fertilizers are added to them. It grows poorly on saline, heavy clayey, strongly acidic soils with close groundwater, so such areas should not be allocated for its crops.
It is not recommended to sow corn on soils heavily infested with weeds, especially pink bitterling, creeping wheatgrass, sow thistle and other rhizomatous and root-bearing weeds.
For normal growth and development, corn needs: oxygen, carbon, hydrogen, nitrogen, phosphorus, potassium, calcium, sulfur, iron, magnesium, and in small quantities manganese, boron, chlorine, iodine, zinc, copper and other trace elements. Plants require the greatest amount of nutrients during the period of cob formation and grain filling.
Corn consumes nutrients before the onset of waxy ripeness of the grain, but with varying intensity according to growth phases. In the first half of the growing season, plants require more phosphorus, potassium and nitrogen, and after flowering - increased nutrition with phosphorus and potassium. Proper soil fertilization and fertilizing of crops is the most important condition for obtaining high corn yields.
Heat Requirements
Corn is one of the heat-loving plants. Its seeds begin to germinate at +8...10°C. However, seedlings at this temperature appear slowly and unfriendly, a significant part of the seeds are affected by diseases and often rot. Therefore, corn must be sown when the soil temperature at the seeding depth reaches at least +10°C.
Corn seedlings are sensitive to spring frosts, but after a single morning frost down to -2...3°C and even -3...4°C, they are able to recover and grow again. At lower temperatures, corn plants die. During autumn frosts, adult corn plants die at a temperature of – 3°C.
The embryos of wet corn grains are also sensitive to low temperatures. If grain is stored at high humidity at subzero temperatures, the seeds lose their viability and become unsuitable for sowing.
A decrease in the average daily air temperature below +10...12°C for a long time, especially in the first period (before stemming), retards the growth and development of plants and lengthens the growing season. The higher the average daily temperature, the shorter the duration of the interphase period, and vice versa, a decrease in soil and air temperatures delays the passage of all phases of plant development and reduces the intensity of growth processes.
Summer drought retards plant growth mainly due to the high consumption of water through evaporation. Already at a temperature of +24...25°C, corn evaporates 2 times more water than at +21°C. The best temperature for the critical period in the life of the plant, which begins 10 days before the start of panicles and continues for 30 days, is +20...23°C.
High air temperature with relatively low humidity during plant flowering, especially when there is insufficient moisture reserves in the soil, has a detrimental effect on the harvest. This is explained by the fact that corn pollen, containing about 60% moisture, quickly dries out and loses its fertilizing ability at temperatures above +32...35°C and at relative air humidity below 30%. The air temperature after fertilization of the cobs and before grain ripening is of less importance for the plant, however, when the air temperature drops to +15...16°C, the formation of cobs and grain ripening are delayed.
Moisture requirements
To form a unit of dry matter, corn requires almost 2 times less water than spring wheat, barley and other grains. Corn is better adapted to dry conditions than other cereal crops. In the first period of its development, it gives a slight increase in above-ground mass and, within a month after emergence, accumulates approximately 1.5–2% of the green mass of the total harvest. At this time, intensive growth of the root system occurs, ensuring the further rapid development of the plant.
The period beginning 8–10 days before panicle ejection and ending at flowering is when corn requires the greatest amount of moisture. At this time, male and female flowers are formed, fertilization occurs, and there is an increased accumulation of dry matter. The corn yield is determined by the moisture content in the soil and the amount of precipitation during this period.
Atmospheric drought, when there is a supply of moisture in the soil, causes significantly less damage to corn than to other cereals. Corn responds very well to soil moisture, and when provided with moisture, it sharply increases the yield.
Light and air requirements
Corn is a light-loving crop; it does not tolerate shade, especially at a young age. For the development of a powerful leaf surface and the formation of ears, it requires a lot of light. In shaded areas, the leaf surface of a young plant is more than two times smaller than in good light.
Corn is a short-day crop, lasting 12–14 hours. In conditions of longer daylight hours, as well as at lower spring temperatures, it increases the total leaf surface area and the weight of green mass, but lengthens the growing season.
Corn needs a good flow of oxygen into the soil both during seed germination and later for the development of a strong root system. Therefore, it grows and develops better on loose, breathable soils. In order to provide corn with enough light and air, it is necessary to keep its crops clean and the soil loose. Then weeds will not shade the corn plants, and air will easily penetrate to its roots.
Place of corn in crop rotation
Corn is placed in field, fodder and specialized crop rotations, as well as in permanent plots as a permanent crop. The degree of its responsiveness to predecessors in different climatic conditions varies. In the southern steppe regions, the main effect of the precursor is determined by its influence on the water regime of the soil. The most severe drying of deep soil horizons in these areas is caused by sunflower, sugar beet, sudanese and perennial grasses. It is not advisable to place corn after such crops.
The yield of corn is highest when it is sown after winter wheat, spring cereal crops, and in years with sufficient reserves of productive moisture in the soil in the spring - after sugar beets.
In the forest-steppe zone of Ukraine, high yields are ensured when sowing corn after winter and spring cereals, legumes, corn, sugar beets, buckwheat, and root tubers.
In Polesie, the best predecessors are peas, potatoes, sugar beets, winter crops, corn, lupine, and perennial grasses.
Basic tillage
In the steppe and in areas of unstable and insufficient moisture in the forest-steppe, the main task of the main treatment is to create conditions for maximum accumulation and conservation of moisture in the soil without weakening the fight against weeds. The timing and technology of fall tillage are determined by the timing of harvesting predecessors. After harvesting cereal grains and legumes, a fairly long warm period remains; it is noticeably shorter after harvesting row crops.
The main tillage for corn after continuous sowing crops usually consists of two techniques: stubble peeling and fall plowing.
Following the harvesting of cereal crops, the soil is treated with disc harrows or harrows to a depth of 6–8 cm. In areas with a long frost-free period, the best results in suppressing weeds are obtained by double husking, with repeated husking to a depth of 10–12 cm, with a gap of 3–4 weeks. . At the same time, over 70% of weeds are destroyed and the number of their seeds in the soil is reduced by 50%.
After large-stemmed crops (corn, sunflower), crop residues are crushed with disc harrows in two directions.
In fields infested with rhizomatous weeds (wheatgrass, horsetail, gumum), cross-hulling is carried out to a depth of 10–14 cm. In case of infestation with perennial root shoot weeds (thistle, field bindweed), repeated peeling is used after 2–3 weeks with ploughshare hullers or flat-cutting cultivators depth 12–14 cm.
Particular attention to the moisture supply of corn should be paid on eroded soils, where, in addition to moisture loss through evaporation, a lot of it is lost due to snow blowing from fields and surface runoff in spring, and often in summer.
In the system of soil conservation tillage without moldboards, after harvesting, loosening is carried out with a BIG-3 harrow, then peeling with a flat-cut cultivator to a depth of 8–10 cm and again to a depth of 12–14 cm.
The depth of treatment depends on zonal characteristics and soil differences. On full-profile soils of heavy mechanical composition, on rainfed lands, the plowing depth is up to 32 cm, on light soils with a small thickness of the humus horizon - up to 22 cm, but not deeper than the arable layer. When protecting soil after stubble predecessors, the loosening depth is up to 20–30 cm, on slope lands after large-stemmed crops – 20–25 cm. In zones of combined action of water and wind erosion in the contour farming system on fields clear of perennial weeds, the tillage depth is: 20–22 cm.
In fields where corn is sown after corn, the quality of incorporation of crop residues increases noticeably after two huskings, which are carried out in two perpendicular directions with disc hulls. After harvesting the sunflowers, the remaining stems and root residues are crushed with a disc harrow and then deeply plowed.
The corn root system develops fairly evenly in all directions. However, most of the roots (up to 70%) are distributed in a 30-centimeter layer, and therefore this crop is very responsive to plowing depth.
It is advisable to plow ordinary and southern chernozems with plows with skimmers to a depth of 27–30 cm, washed-off low-humus chernozems, chestnut steppe soils and forest-steppe chernozems – to 25–27 cm.
Pre-sowing treatment
In the spring, as soon as the soil condition allows, the plowed land is harrowed in one or two tracks with heavy harrows in a short time - two to three days. Delay in harrowing in dry, windy weather leads to moisture loss. During the day they reach 50–60 t/ha and more. Harrowing is more effective across plowing. An indicator of its high quality is good leveling of the arable land, a loose, finely cloddy soil layer 4–5 cm deep.
Pre-sowing tillage when cultivating corn is carried out without a break in time, following the treatment with disc harrows, so as not to lose soil moisture.
For corn, two different-depth plow cultivations with harrowing are required, and in dry, windy weather, rolling. The first cultivation is carried out as early as possible, the second - immediately before sowing.
The depth of cultivation, especially the first one, depends on the type of soil and prevailing weather conditions. In most areas of insufficient moisture, it is advisable to carry out the first cultivation at a greater depth, and the second at a shallower depth - at the depth of seed placement.
Corn fertilizer
Corn is demanding on soil fertility and, when producing high yields, which are obtained more often when plants are provided with moisture, it consumes a large amount of nutrients. To form a grain yield of 60–70 c/ha, their consumption is approximately: 150–180 kg/ha of nitrogen, 50–60 phosphorus, 150 kg of potassium; and for a yield of 100 c/ha, respectively: 390, 110 and 360 kg/ha.
Plants consume nutrients from the soil throughout the growing season. The absorption of nitrogen and potassium ends earlier, and phosphorus enters the plants almost before ripening.
In the zone of insufficient and unstable moisture on ordinary, medium and deep chernozems, corn produces high grain yields when nitrogen and phosphorus fertilizers are applied, and on soddy-podzolic soils, podzolized and leached chernozems, and gray forest soils - nitrogen fertilizers. On light soils, as well as after predecessors that consume a lot of potassium (root crops, sunflowers, etc.), potassium fertilizers must be applied first.
Fertilizers are applied in the fall or spring, before plowing or cultivation (the main fertilizer), during sowing - in the rows, and during the growth period - as top dressing.
A noticeable increase in yield is achieved by local application of fertilizers using cultivators-plant feeders KRN-4.2 during the first or second cultivation of plowed land to a depth of 10–12 cm. As a result, more favorable conditions for plant nutrition are created during the initial period of growth and throughout the entire growing season.
Sowing corn
Sowing dates and seed placement depth
Corn should be sown when the soil at the seeding depth warms up to at least +10°C, and sowing should be completed within a short time. If the forecast suggests a rapid increase in temperatures, then sowing corn can begin a little earlier. It must be borne in mind that when sowing corn either too early or too late, the yield is reduced.
When sown in cold soil, the seeds swell, do not germinate for a long time, and some of them are damaged by fungal diseases and die. The seedlings are sparse and develop poorly. The timing of sowing corn is set depending on local soil-climatic characteristics and weather conditions specifically for each area allocated for corn.
In areas that are free of weeds and sparsely populated by pests, corn should be sown at the beginning of the optimal sowing time, and in weedy areas - at the end of this period, after additional measures have been taken to kill weeds.
The depth of planting corn seeds depends on the soil and climatic conditions of a particular growing zone.
The question of the depth of planting corn seeds should be decided differentially for each site separately. It should be borne in mind that deep planting of seeds on soils that are heavy in mechanical composition and not sufficiently heated has a negative effect on the emergence of seedlings and often leads to thinning of crops. On the other hand, seeds should not be planted too shallowly, since in this case they end up in the upper dry layer of soil and do not germinate well. In addition, corn seedlings with shallow planting can be damaged when harrowing the crops. In each individual case, the seed placement depth is set depending on the sowing time, soil moisture, its mechanical composition and spring weather conditions, especially temperature.
Full-fledged, friendly shoots can be obtained by sowing seeds at a depth where they will be provided with a sufficient amount of moisture, air and heat. In southern, arid and semi-arid regions, on chernozem soils, optimal conditions for seed germination are usually created at a depth of 8–10 cm, and if the soil dries out significantly at the time of sowing, at a depth of 10–12 cm. The depth of planting corn seeds in forest-steppe and woodland is necessary set depending on the properties of the soil, its moisture and sowing time. The optimal seeding depth is 6–8 cm, and in conditions of excessive moisture, especially on heavy, cohesive soils - 5–6 cm. In the western regions, seeds should be sown to a depth of 6–8 cm. On heavy, waterlogged soils, it is reduced by 1–2 cm, and on lighter, sandy loams they increase by the same amount.
Optimal plant density
When mechanized corn cultivation, it is important to ensure optimal plant density by appropriately adjusting the seeders for a given seed placement. It should be assumed that, depending on the soil and climatic conditions and the morpho-biological characteristics of the cultivated hybrids or varieties, the optimal plant density varies over a wide range.
The standing density before harvesting, depending on the moisture zone and the characteristics of the hybrid, ranges from 55 to 95 thousand/ha (see table). In quantitative terms, this is 15–22 pieces. seeds per three linear meters, in weight terms, depending on the mass of 1000 seeds, 20–30 kg. Taking into account field germination, the seeding rate is increased by 10–15%.
Optimal standing density at the time of harvesting corn hybrids from the Pioneer company (thousands of plants per 1 ha)
| Ripeness group | Steppe (rainfed conditions) | Forest-steppe | Polesie |
| FAO 100–200 | 65–70 | 80–85 | 90–95 |
| FAO 200–300 | 60–65 | 75–80 | 85–90 |
| FAO 300–400 | 55–60 | 70–75 | 80–85 |
| FAO 400–500 | 50–55 | – | – |
With such an increase in the specified sowing of seeds, the decrease in field germination, partial damage to seeds and young seedlings by gnawing pests and diseases, as well as when harrowing seedlings, is fully compensated and optimal or close to it plant density is ensured.
Crop care technology
Harrowing and cultivation of crops
Timely and proper care of corn crops is a decisive condition for obtaining high yields. Care of corn crops can be completely mechanized.
The first time they harrow it is 5-6 days after sowing corn, when the weeds are still in the state of white thread-like seedlings and have not yet had time to reach the soil surface. You cannot be late with harrowing, as the weeds will have time to get stronger and will be difficult to destroy with harrows. If the weather is cold and damp, delaying the emergence of corn seedlings, and weeds begin to sprout again, harrowing is repeated.
When corn shoots appear on the field, the crops are harrowed again to loosen the soil, increase air access to young plants and destroy emerging weeds.
To avoid covering young corn plants with soil and not tearing them out when harrowing, special attention should be paid to selecting the appropriate type of harrow (light, medium or heavy) depending on the compaction of the soil.
With timely harrowing of corn crops, not only the seedlings of annual weeds are destroyed, but the soil crust is also well loosened, and labor costs for further care of the crops are also greatly reduced.
When 3-4 leaves appear on the corn plants, the first inter-row treatment of the crops is carried out. During the first loosening, the cultivator's tines are positioned so that a protective zone of 10–12 cm remains between the outer paw and the row of corn plants. All cultivator tines and razors must be located in the same horizontal plane and have an overlap (3–4 cm), ensuring complete cutting of the weeds. To protect young corn plants from being covered with soil during the first loosening, you should use one-sided razor paws. The second time, the row spacing is loosened not immediately, but after 4–5 days, in order to allow weeds to germinate.
To combat weeds in protective zones, additional working bodies are used, installed between the sections of the working bodies of cultivators - row weeding harrows with high spring teeth, discs of rotary hoes, as well as hillers for sprinkling the weeds with soil in the rows.
Additional working tools for row-crop cultivators should be used taking into account the weediness of the crops, soil moisture and the height of the corn plants. The best results are provided by additional working bodies against the background of previous pre- and post-emergence harrowing, while weeds that germinate in a later period are destroyed.
To destroy weeds in protective zones, additional working bodies are used, installed between the sections of the working bodies of cultivators - row weeding harrows with high spring teeth, if necessary - and dump paws in dry areas or hillers in areas of sufficient and excessive moisture to cover the weeds with soil in the rows and nests.
Chemical weed control
The chemical method is very effective for controlling weeds in corn crops. It not only allows you to thoroughly clean the corn field from weeds, but also significantly reduces labor and cost costs.
The choice of herbicide depends on the species composition of weeds in each specific field, the degree of weed infestation, the availability of one or another special equipment for their application; in more rare cases, it is necessary to take into account the individual tolerance of a particular hybrid to a particular active substance on the basis of which the drug is made. First of all, they must work on a wide range of weeds, not harm the corn, and not pollute the environment and the resulting products. Such herbicides include: Dual Gold 960 EC
(against annual cereals and dicotyledons, application rate - 1.6 l/ha),
Primextra Gold 720 SC
(against annual cereals and some dicotyledons, application rate - 2.5–3.5 l/ha),
Frontier Optima
(against annual dicotyledons, application rate - 0.8–1.4 l/ha),
Milagro
,
Callisto
,
Banvel
,
Titus
,
Roundup
(if the fields are heavily infested with perennial root shoot weeds - 2–3 l/ha). With their help, the issue of removing weeds from almost all types of corn crops is resolved.
The best time to spray corn crops with herbicides is the period when the plants are in the phase of up to 5–6 leaves. With later treatment, in the phase of eight or more leaves, most of the drug settles on the plants, which can cause serious damage to them.
Crops should be sprayed only in clear and warm weather at a temperature not lower than +14...15°C. They process crops with various ground machines and equipment.
When perennials spread locally, crops are sprayed selectively, using increased doses of herbicides. With this treatment, the sprayer is put into operation only in clogged areas. This allows you to save herbicides and effectively combat harmful weeds.
When chemically weeding corn crops, it is necessary to take into account that the effect of herbicides, especially on perennial root weeds, affects gradually, therefore subsequent cultivation is carried out after the weeds begin to die off.
Sometimes after chemical weeding of corn crops, the stalks become more brittle. In this case, the next inter-row treatment begins 2-3 weeks after spraying, when the plant stems regain strength.
The effectiveness of the preparations depends on the mechanical composition of the soil and its moisture. Light, low-humus soils require smaller doses than heavy or humus-rich soils. The abundance of moisture in the soil, promoting the dissolution of herbicides, favors their action.
Diseases and pests of corn
Diseases
Corn, more than other grain crops, is affected by numerous diseases, among which the following are important: molding of seeds and sprouts, bubbly and loose smut, root and stem rots, cob diseases - fusarium, nigrosporosis, bacteriosis and white. Helminthosporiosis and rust occur in wetter years in the second half of summer.
Mold of seeds and sprouts
occurs in the form of browning of seedlings and a blue-green or white-pink coating of the fungus on the grains. Seeds infected with mold fungi lose their viability.
P blister smut
– a fungal disease that affects all parts of the plant: stem, leaves, panicles, cobs. Manifests itself in the form of swellings of various sizes and shapes. The largest swellings occur on the cobs and stems. When the swelling matures, the shell bursts, the spores are released and are easily carried by the wind. The most harmful form is damage to the cobs, in which the reduction in plant productivity reaches 30%.
Dusty smut
affects only panicles and ears. It usually appears at the end of plant flowering. The panicles turn partially or, rarely, entirely into a dusty mass, and the ears are always reduced into a black, dry, cone-shaped lump consisting of a large number of spores. Sick plants are stunted, bushy excessively, and their leaves grow excessively.
Root
and
stem rots
are very harmful. Signs of this disease are discoloration or browning of tissues in milky, milky-waxy ripeness of the grain, lodging of plants, wilting of leaves and death of plants (two to three weeks before ripening).
Fusarium
- a disease that affects corn cobs. A cobweb-like pale pink coating of mycelium appears on diseased cobs. The kernel of the affected ear becomes a dirty pinkish-brown color, often extending to the peduncle, involucre, and stem node to which it is attached. Grain affected by fusarium becomes dull pink, decreases in weight and reduces germination.
Nigrosporosis
affects the ears during their formation and especially in the period between ripening and harvesting. Diseased ears are often underdeveloped and lightweight; their stem is loose, grayish, with a blue tint. The cobs are easily split lengthwise and broken crosswise, with the core breaking up into separate bundles of fibers. The grains on the cobs are often underdeveloped, dull, slightly grayish in color, and loosely packed.
Cob bacteriosis
manifests itself in the form of depressed pale gray spots with a diameter of 2–3 mm on the crown of the caryopses. Under unfavorable storage conditions, seeds affected by bacteriosis become more moldy. The sowing quality of seeds deteriorates, they give reduced germination, and are more susceptible to mold during germination. The development of the disease is facilitated by damage to the grains by the bread bug.
Helminthosporiosis disease
on corn it occurs sporadically and manifests itself in the formation of oblong concentric brown spots on the leaves, the length of which sometimes reaches 10 cm. The spots form first on the lower leaves, gradually spreading to the younger ones - the upper ones. With severe development of the disease, the spots merge, causing the leaves to dry out. The infectious origin (mycelium, spores) remains on the affected plant residues of corn. The disease is favored by warm weather with frequent precipitation in the second half of the growing season.
For rust
On the leaves of corn on both sides, inconspicuous, yellowish-pale spots are initially formed, surrounded by a halo. They then turn into randomly scattered small, round or slightly oblong yellowish-brown or brown uredospore pads. The disease appears in the second half of summer and develops until the end of the growing season.
Pests
From the period of germination of sown seeds and throughout the growing season, corn is damaged by many types of harmful insects. The most dangerous of them are larvae), darkling beetle
and
pollen eaters
(
false wireworms
), cutworm
(winter, exclamation
) caterpillars,
Swedish fly
, southern
gray weevil
,
corn borer caterpillars.
gophers
and
mice
cause great harm .
Other types of insects also cause significant harm: meadow moth, corn beetle, cotton and cabbage bollworm, ground beetle, ground beetle, aphid, bread bug and fleas.
During the period of germination of corn seeds, the most dangerous are the larvae of the common and striped click beetles (wireworms), the larvae and beetles of the darkling beetle, the southern gray weevil, and the mole cricket. Seedlings and young plants are damaged by caterpillars of the meadow fly, ground fly, click beetle larvae, and Swedish fly. Stems, ears, panicles, and leaves are damaged by caterpillars of corn and meadow borers, cotton and winter cutworms, Swedish fly larvae, flea beetles, and aphids.
Measures to combat pests and diseases of corn
The system of measures to protect corn from pests and diseases includes organizational, economic, agrotechnical, chemical and biological control methods. Using them in combination allows you to reliably preserve the crop from loss.
To protect corn from diseases and pests, proper preparation for sowing is of great importance. One of the most important measures in the fight against diseases and pests of corn is seed treatment. It protects against mold during the germination period, destroys infection of fusarium, nigrospora and other diseases, prevents the introduction of dusty and blister smut into areas where there is no infection of these diseases. Dressing is carried out at corn processing plants by moistening or using an aqueous suspension of preparations at the rate of 5–8 liters of water per ton of seeds. In this case, a corn protectant is used based on such active ingredients as carboxin + thiram, fludoxonil + metaloxyl. Treating seeds with combined disinfectants better protects them from diseases and from soil-dwelling gnawing pests (wireworms, pseudowireworms, larvae of lamellar beetles, caterpillars of gnawing cutworms).
Correct placement of corn in crop rotation is important in the fight against pests and diseases. Rotation of crops limits the contact of the host plant with pathogens and pests. The longer corn is cultivated in one place or often returns to the same field, the faster the incidence of smut, stem and root rots increases, and the number of southern gray weevil and corn borer increases. To reduce the number of southern gray weevils, rotation of corn and sunflowers with cereals is especially important.
When sowing at the optimal time, corn is less affected by diseases and pests. Excessively early dates lead to severe molding of the seeds and increase the incidence of root and stem rots, wireworms, and mole crickets. Plants sown too late are more susceptible to blistering and loose smut, Swedish fly, and fall armyworm, and unripe ears are more susceptible to nigrospora and cotton bollworm, as well as to mold in the field and during storage.
Planting seeds at a normal depth (8 cm) reduces molding of corn seeds and seedlings. With deeper embedding, molding and damage by wireworms increase. In conditions of insufficient moisture, rolling the soil after sowing improves germination conditions and reduces seed molding and root rot.
Timely and thorough inter-row tillage with the application of fertilizers during the growing season of corn helps to conserve moisture, which increases the plant's resistance to smut, root and stem rot, Swedish fly, wireworms, and fall armyworm. When loosening and weeding, weeds are destroyed - reservoirs for infection of a number of diseases and habitats for pests, as well as insects - carriers of diseases.
In the fight against winter cutworms and other gnawing armyworms, careful cultivation of the fallow field and loosening of the corn rows during the period of oviposition and the beginning of caterpillar hatching is of great importance, during which a large number of eggs and weeds that serve as food for the caterpillars are destroyed.
To protect crops from the meadow moth, deep autumn plowing of areas infested with cocoons, early sowing dates, regular weed control, and inter-row tillage during the cocooning period of the moth are important.
One of the leading links in agrotechnical and organizational and economic measures to combat diseases is corn harvesting and post-harvest activities. A mandatory requirement in this case is timeliness and reduction of cleaning time. When there is a delay in harvesting corn for grain, the incidence of cobs with nigrospora, fusarium, mold fungi, and losses from the corn borer and cotton bollworm increase.
Reducing crop losses from diseases is achieved by cultivating more resistant varieties and hybrids.
Corn harvesting
Harvesting food and feed corn for ripe grain begins at the end of wax - beginning of full ripeness and is completed in a short time. The accumulation of organic matter in corn grain stops when it reaches a moisture content of 40%. Subsequently, harvest ripeness occurs at 30–35% humidity. The harvesting period for grain should not exceed 15–20 days; if delayed, losses increase. They are especially significant when corn is damaged by frost and in wet weather. This is due to increased respiration of wet standing grain and damage to it by fungal diseases, as well as a significant deterioration in the quality of harvesting by combines due to drooping ears and their moisture.
Corn for grain is harvested in the form of cobs or with simultaneous threshing of the cobs. The first harvesting method includes cutting the plants, separating the cobs, chopping the stems, cleaning the cobs from the wrappers, drying and threshing the cobs in a hospital. For this purpose, corn harvesters KOP-1.4 V, “Khersonets-7”, “Khersonets-200”, KSKU-6, cob cleaner OP-15, threshers MKP-3.0 and MKP-12, a stationary post-harvest processing station and corn storage.
When harvesting according to the second method, the plants are cut, the cobs are threshed and the stems are crushed using a KSKU-6 combine or grain harvesters, and the grain is cleaned and dried in a hospital.
The operation of combines is organized in accordance with the selected harvesting scheme.
The most progressive form of organizing continuous harvesting of corn for grain, as well as an example of highly efficient use of technology, is the use of integrated harvesting teams, which ensure an increase in the average daily output of the combine by 1.2–1.5 times, a reduction in harvesting time and a reduction in losses compared to single operation of units . Share on social networks:
How to grow corn in the country
The technology for growing corn is quite simple; it can be grown not only in the southern regions, but also in the middle zone. To do this, it is enough to create the appropriate conditions.
Note: Corn is heat-loving, so its seeds can be planted when the threat of frost has passed, in well-warmed and sufficiently moist soil.
For the southern regions, this time occurs in mid-May, for the northern regions - at the end of May and beginning of June.
In order to increase the crop's resistance to low temperatures, the seeds are pre-planted in early May in peat-humus pots. By the end of the month, the finished seedlings can be moved to the garden bed.
grow corn in your garden :
- Seeds are planted when the soil warms up to 17 degrees at a depth of 5 cm.
- In case of poor germination, 2-3 grains are placed in each nest.
- Planted in rows, placing the holes at a distance of 30 cm from each other.
- The interval in the row between holes should be 15 cm.
- The seeds are not immersed in the soil too deeply - to a depth of 7 cm.
- The seedlings are thinned out when the sprouts have 4 leaves.
- Loosening and weeding of row spacing is carried out regularly.
- Watering is carried out as the beds dry out.
- Fertilizing and hilling are carried out regularly.
- To obtain large cobs, remove side shoots
By following these recommendations, you can achieve significant results by harvesting early varieties in mid-August, and late-ripening varieties by the end of summer.
What conditions are necessary for growing crops?
When planting seeds, it is necessary to withstand certain agroclimatic requirements:
- The soil should warm up to at least 8 °C.
- The place has good lighting.
- The site is protected from strong winds.
- Moisture does not stagnate and does not leave the soil very quickly.
- The variety corresponds to the climatic zone.
Precursors to corn can be tomatoes, cabbage, potatoes or legumes.
If the crop is constantly grown, it is necessary to replace the plot after 3 years.
Soil composition
A good corn harvest is guaranteed when grown on loose soils, such as:
- black soil;
- floodplain loams;
- light loams.
There is a low chance of growing corn if the soil on the plot is:
- heavy clay;
- strongly saline;
- swampy;
- sour.
Illumination
Growing corn requires good lighting. This crop cannot be planted in shaded conditions. Normal plant growth, flowering and crop formation are possible with 12-14 hours of daylight.
Temperature
Corn begins to grow only in well-warmed soil. When planting seeds in open ground, the ground temperature should be 8-10 °C. In cold climates, it is permissible to sow seeds in a greenhouse or under film. Plant vegetation begins at a temperature of +10 °C and stops if the soil is heated to +30 °C. Optimal seedling growth is observed at 10-12 °C. To start flowering, a temperature of 22-25 °C is required.
Humidity
Corn, despite its drought tolerance, loves well-moistened soil. The optimal soil moisture is 75%. The required level is maintained by regular watering. In the case of arid climates, automatic systems cope well with this task. When growing plants in a greenhouse, constant drip irrigation is used.
Favorable and undesirable neighborhood
Successful companions for corn include:
- zucchini;
- pumpkins;
- cucumbers;
- salad;
- beans;
- peas;
- beans.
Planting after or near switchgrass can spread the corn borer, which attacks both crops equally.
Sowing
When choosing a site, preference is given to a warm, sunny place. Light soil with good water drainage is best. Soil fertility is important. Therefore, organic and potassium fertilizers are added to the soil in advance. Immediately before sowing, the soil is leveled, breaking up lumps of earth.
Growing from seeds
To obtain tasty and juicy grains, the seeds are processed before sowing (Figure 2). To do this, it is enough to warm the grain in the sun for 3-4 days, and then soak it in a solution of potassium permanganate for 20 minutes, rinse it and put it in a warm place for germination. With the appearance of small roots, the seeds can be planted in the ground (Fig. 3).
Small holes 6-7 cm deep are made in the prepared soil, into which 3-4 seeds are dropped and sprinkled with soil. With the appearance of the first shoots, a thinning procedure is carried out, leaving two shoots in each nest. This ensures resistance to lodging.
Note: It is best to grow corn in 4 rows to ensure cross-pollination.
Figure 3. Scheme for sowing corn in open ground
Those who want to get an early harvest should start growing from seedlings. It can be obtained by sowing a small amount of grains in separate containers to a depth of 2 cm in mid-April. Already in mid-May, the finished sprouts can be transferred to open ground.
Growing from seedlings
In regions with a short thermal period, growing all kinds of crops from seedlings is the most justified and effective.
Thus, the seeds are sown in special pots filled with a nutrient substrate, which includes compost, sand and peat in a ratio of 2:1:1 (Figure 4). In addition, it would not hurt to add wood ash to this nutrient medium at the rate of 200 g per half bucket.
Figure 4. Growing corn seedlings
In each cup prepared in this way, plant one grain to a depth of 2-3 cm, sprinkle with sand, leaving space for adding soil and watering.
10 days before planting seedlings in open ground, they are fed and watered abundantly.
From the video you will learn how to properly grow corn seedlings.
Corn pest control
Corn is one of the most attractive crops for wireworms (larvae of the click beetle). They just appear in the world at the end of May - beginning of June, they are very voracious and are capable of destroying young plants. Therefore, when digging in spring (enough for a spade bayonet), you need to carefully select and destroy pests, add lime or ash to the acidic soil, and treat heavily contaminated soil with a special preparation (Barguzin, Pochin, Provotox).
If you don’t want to deal with “chemistry” once again, you can go the other way. Cut potatoes, carrots, beets into large slices and bury them to a depth of 10–15 cm. Every 3–4 days, check the baits and destroy the wireworms that have collected in them. To make it easier to remove traps from the ground, stick wooden twigs into them before burying them.
Corn - planting and care in open ground
With the square-nest method, 3 grains are placed in each designated hole, sprinkled with a damp substrate and mulched with dry soil. After the seedlings appear, they are thinned out, leaving one of the most viable sprouts in each corner of the square.
Note: To achieve a continuous harvest throughout the warm period of the year, a conveyor planting method is used. The essence of this method is to sow varieties with different ripening periods in two weeks.
It is also worth paying due attention to feeding. Humus and compost, as well as manure obtained from cows and chickens, can be used as organic fertilizers. They are added after the formation of 6 true leaves. Among the chemical compounds you can choose potassium fertilizers, superphosphate, and ammonium nitrate in liquid form.
Choosing a landing site
When choosing a site for growing corn, preference should be given to sunny places protected from the winds. The soil should be light and moderately moist. They are pre-enriched with mineral and organic fertilizers. Before planting corn in heavy, clogged soils, they are dug up, fluffing them up and ensuring drainage. The place for the culture must be changed every 3 years. The predecessors of corn can be potatoes, cabbage, legumes, and tomatoes. It gets along well with zucchini and pumpkin.
You cannot sow corn immediately after millet. This contributes to the spread of a common plant pest, the corn borer.
Plant care
Care measures include weeding, loosening, removing shoots, watering, fertilizing and hand pollination.
Weeding is extremely important immediately after planting. Since corn seedlings grow slowly, they need to be kept free from weeds that can choke out the crops.
The procedure for loosening row spacing is carried out about 3 times during the entire growth period. It is important to know that the depth of loosening is inversely proportional to the height of the seedling. In other words, the higher the stem, the shallower the soil should be loosened.
Figure 5. Corn fertilizer application steps
Often, in order to obtain a good harvest, additional pollination is carried out manually. To do this, lightly shake the panicles that appear at the top of the stem. As a result, pollen from one plant flies to another. This is how cross-pollination occurs, which ensures the formation of large ears with large seeds.
Often, during a period of intensive growth, for various reasons, side shoots (stepchildren) begin to form on the stem. They slow down the growth of the crop and contribute to the formation of small ears. Therefore, to obtain the desired result, the stepsons are cut off or trimmed.
Pests and diseases
Corn can be affected by:
- rust;
- rot;
- fusarium;
- mosaic.
In rainy summers, young plantings are sprayed with Fitosporin for prevention, and the seeds are pickled in a solution of potassium permanganate before planting. Sick plants are destroyed.
They parasitize on crops:
- wireworm;
- scoops;
- meadow moths.
For prevention, crop rotation is observed, and traps are laid out for wireworms. It is permissible to use insecticides before flowering.
Harvesting
Cobs at the stage of milky ripeness are removed as follows: hold the stem with one hand, and unscrew the cob from it with the other. You should know that the top ones ripen about a week earlier than the bottom ones. Therefore, harvesting is carried out in several stages. Harvesting cannot be delayed, as a significant delay can affect the taste and quality of the grains.
Note: Harvested milk cobs are not stored for long. They should be eaten immediately, processed for canning (freezing), or stored in the refrigerator, without removing the leaves, for a period of one week.
A month after the milk cobs have been collected, it is time to harvest the seeds. The signal to start harvesting will be the darkening of the stem and the drying of the leaves. The cobs are separated from the stem by twisting them slightly. Then the covering leaves are removed and left to dry. Dried grains lend themselves well to husking.
The collected planting material is stored in a dark, dry and cool place in a hermetically sealed container. In this case, it will retain its ability to germinate for up to 10 years.
Joint planting of different crops
The plant coexists well with other crops, and the best neighbors for maize are legumes: peas, beans, as well as zucchini, sunflowers, pumpkins, melons or potatoes. For these plants, maize serves as both natural shelter and support. Buckwheat, melons and legumes will be good predecessors for cereals.
Seeds of corn and beans can even be planted in one hole, and then the seedlings do not need to be thinned out. This mutually beneficial relationship is based on the fact that maize receives nitrogen from the soil, which is produced by beans. She, in turn, uses the corn stalks as a support for growth.
Combined planting of cucumbers and corn
The same successful symbiosis of maize with cucumbers and pumpkin, which corn protects from strong winds and prevents their fruits from lying on the ground. At the same time, partner plants should not be allowed to overtake the grass in growth, creating unnecessary shading. It is not recommended to plant corn and tomatoes together.
The optimal plantings after corn are legumes, beets, carrots, perennial greens or winter grains, and leafy vegetables.
Kinds
Fruits of the sugar type maize
There are only 8 types of cereal crops, and only 5 of them are of industrial importance:
1. Sugar. It has received the widest distribution and is most often used in breeding due to the milky and sweet taste of the cobs. Mostly young grains are eaten
2. Starchy. It is characterized by a high starch content and is also called flour or soft. Used for the production of molasses and corn flour, it lends itself well to processing. The grains are large, white or red
3. Dentoform. The cobs have large, rich yellow grains. It is resistant to diseases and has high yield. Used as feed and industrial raw materials, but also eaten
4. Indian. Another name is siliceous. An early-ripening, starchy species, the grains of which are used to produce corn flakes and grits. A characteristic feature is grains of different sizes, which can be white, light yellow and even almost black.
5. Bursting. Mainly used in the food industry for the production of popcorn
6. Wax. Least valuable species. It has poor resistance to adverse influences and produces small yields. The grains are white and yellow, covered with a waxy film
Another 2 species (membranous and sharp-grained) do not have food or industrial value.
Pre-sowing seed treatment
March, April
At temperatures between 10 and 15 C, corn can be grown in seed trays on a windowsill in the home. The pots used for this purpose are filled with sterile seed compost, approximately 10 cm high, with a reduced nutrient content.
To ensure that the seeds germinate well, the seeds are soaked in warm water for 6-10 hours before sowing. Then the grain is pressed with the tip down to the surface at a distance of 5 cm and covered with 2 cm of sand, vegetable or compost soil. Watering is carried out regularly.
Mid to late May
after the last frost, plants are planted in blocks measuring 45x45 cm: larger ones to the north, smaller ones to the south. Carefully remove well-watered plants from their pots. The root ball should go deep into the ground (so that the plant can again form support roots from the stem), and it should be pressed well and watered thoroughly.
Depending on the temperature, the seeds should be covered with plant tissue for the first few days outdoors.
Because sweet corn is wind pollinated, planting in groups is more convenient than in rows. This arrangement is intended for cross-pollination. To avoid pollination by low-sugar corn varieties, it is also recommended to stay about 500 meters away from the next vegetable plot.
Seed selection and preparation
Corn planting technology begins with choosing a hybrid. This must be done taking into account the climate of the region. At the same time, leading positions are occupied by such companies as Pioneer, Syngenta, Monsanto. The properties of the planting material of these organizations comply with European standards.
When following corn sowing technology, it is important to pay attention to seed preparation. They need to be dried so that the humidity parameters are 13-14%. After which the planting material needs to be calibrated and fungicidal and insecticidal agents applied.
Important! It is necessary to plant quality seeds. Their germination rate must be at least 85%, and their purity must be at least 98%.
Before planting, it is important to select and prepare the seeds correctly.
Fertilizers
Fertilizer application must be carried out according to the scheme. The main use of fertilizers is in the fall or spring before planting. There is also pre-sowing application and feeding during the period of growth and ear formation.
Corn needs phosphorus and potassium. These substances make it more resistant to temperature fluctuations and lack of water. They also improve the amino acid composition of protein components in grains. Phosphorus and magnesium promote the formation of whole and full grains and also accelerate ripening. It is very useful to feed the bushes with zinc.
Important! The quality of the crop depends most on nitrogen. It not only stimulates fruiting, but also increases the content of nutrients in cereals.
The maximum need for nutrients is observed during the active growth of the vegetative mass and the formation of panicles. At the same time, the application of fertilizers helps to increase yield parameters by 10-12%.
The best predecessors for corn
To increase the yield of any agricultural crop, crop rotation , i.e. annual rotation of crops on the same sown area.
The most favorable precursors for corn are potatoes, legumes and winter wheat. Our cereal produces good yields after alfalfa in fallow areas.
Corn produces good yields in fallow fields where alfalfa grew
If the acidity of the soil does not exceed the norm - from 5.5 to 7 pH, with the systematic application of properly selected fertilizers, corn can be sown as a monoculture, i.e. several years in a row on the same sown areas .
