2016 Corn Production Technical Guidance

I. Promote superior varieties

In view of the different disastrous weather that spring corn and summer corn may encounter during their growth periods, it is recommended that for feed and food types, Suyu 20, Suyu 22, Nongle 988, Denghai 11, etc. be selected, and for fresh-eating corn, "Zhongnuo No. 2" should be the main choice. Buy coated seeds that have been carefully selected as much as possible to prevent underground pest damage during the seedling stage.

II. Sow at the appropriate time according to the crop rotation

Sowing at the appropriate time should achieve "earlier in spring, later in summer." It is recommended to advance the sowing period of spring corn to late March to Qingming Festival, and postpone the sowing period of summer corn to mid-to-late June, so as to avoid damage to corn seedlings by planthoppers after wheat harvest. The germination rate of sweet and waxy corn is relatively low (especially when sown in early spring), so it is recommended to use plastic greenhouses, simple arched sheds, and plastic tray hole seedling methods in mid-to-late March to raise young seedlings and increase the germination rate. In early April, after the average daily temperature stabilizes at 10°C, transplanting, film breaking, and open-field direct sowing can be carried out. The latest sowing period for autumn corn is around July 20, and the latest sowing period for fresh-eating corn is until the Beginning of Autumn.

III. Reasonably increase planting density

Sun the seeds for 2-3 days before sowing to improve the emergence rate and uniformity. Control the sowing rate at 2.5-3.0 kg/mu, and adjust it as appropriate according to variety characteristics to ensure that the number of emerged seedlings reaches 2 times the suitable number of ears. The sowing depth is 3-5 cm. For equidistant row planting, the row spacing is about 60 cm; for wide-narrow row planting, the wide row spacing is 80-90 cm and the narrow row spacing is 30-40 cm. After emergence, check and fill gaps in the seedlings in time, and thin and finalize the seedlings early. Generally, thin seedlings at the 3-leaf stage and finalize them at the 5-leaf stage. Remove weak, diseased, and insect-damaged seedlings in time, and keep strong, uniform, and even seedlings to improve population uniformity. Under high fertility levels, the density of density-tolerant varieties can be about 5,200 plants/mu. During the jointing stage, remove small and weak seedlings in time, and during the tasseling and silking stage, pull out empty stalks, striving for an effective ear number of 5,000 plants/mu.

IV. Scientific fertilizer management

In view of the current situation in which farmers commonly apply compound fertilizer as base fertilizer for corn, nitrogen, phosphorus, and potassium fertilizers can be applied in combination. In production, microelement fertilizers should be added; in zinc-deficient plots, apply 1-2 kg of zinc sulfate per mu. In fertilizer management, organic fertilizer, phosphate fertilizer, potassium fertilizer, and microelement fertilizer should be used up before corn jointing (they can be applied as base fertilizer, seed fertilizer, and seedling fertilizer, and should be applied as early as possible). Nitrogen fertilizer should be applied in stages: lightly apply seedling fertilizer, heavily apply ear fertilizer, and supplement with flower-grain fertilizer; nitrogen fertilizer should be applied into the soil and avoid broadcasting. Base fertilizer: generally apply 2,000 kg of decomposed organic fertilizer, 7.5 kg of phosphorus pentoxide, and 5.5 kg of potassium fertilizer per mu as base fertilizer. Seedling fertilizer: before corn jointing, apply about 30% of the total nitrogen fertilizer together with other fertilizers in a deep furrow along one side of the seedlings, 15-20 cm from the seedlings and about 15 cm deep, to promote root growth and strong seedlings. Ear fertilizer: at the large trumpet stage of corn (when the 11th-12th leaves have unfolded), apply 40%-50% of the total nitrogen to promote large ears and many grains. Flower-grain fertilizer: in areas where conditions permit, apply 10% of the total nitrogen at the flowering stage to prevent premature aging and increase grain weight. To prevent and resist lodging, 1 stick of Weitaling No. 2 can be mixed with 30 kg of water per mu and sprayed at the large trumpet stage to appropriately reduce height, strengthen stalks, and prevent lodging.

V. Integrated control of diseases, insects, and weeds

For weed control after sowing and before emergence, use atrazine mixed with another herbicide, such as 150 g atrazine plus 200 g of 50% prometryn; 150 g atrazine plus 100-150 mL of 72% Dual; 150 g atrazine plus 300-350 g of 48% Lasso, etc. When the soil is moist, spray with 30-50 kg of water per mu, and prevent repeated spraying or missed spraying. As corn is a tall-stalk crop, disease and insect control in the later stage is difficult. Therefore, at the large trumpet stage of corn, pesticides should generally be applied once to control multiple diseases and insects in the middle and late stages of corn, reduce the base number of later disease and insect occurrence, and lessen the degree of disease and insect occurrence. Per mu, 5-10 mL of 20% chlorantraniliprole suspension concentrate or 15-20 mL of 22% thiamethoxam • lambda-cyhalothrin microcapsule suspension plus 30 mL of 25% pyraclostrobin emulsifiable concentrate can be mixed and sprayed.

VI. Harvest at the appropriate late time

The corn harvest time should be determined when, after the ear husks wither, loosen, and turn white, the milk line of the corn kernels disappears and the black layer appears, ensuring full maturity. Varieties suitable for silage can be harvested at the appropriate time, and the stalks can be ensiled as feed to increase income.

VII. Implement disaster-resistant contingency measures

First, dig a complete field ditch system so that the internal and external three ditches are connected, ensuring irrigation in drought and drainage in waterlogging. Second, after a disaster, promptly lift and straighten lodged corn; corn that lodges before the small trumpet stage should be lifted and straightened in time, and the soil should be shallowly earthed up to promote downward root growth. Third, after waterlogging, if fertilizer loss is severe, promptly apply restoration fertilizer (mainly nitrogen fertilizer).