What are the field management measures for summer corn in the middle and late stages

1) Timely intertillage and topdressing to meet nutrient needs. During the jointing to small trumpet stage (from 6 leaves unfolded to 10 leaves unfolded), apply fertilizer in combination with intertillage. Through intertillage, destroy wheat stubble, loosen the soil, and control weeds. Topdressing should be mainly nitrogen fertilizer; do not broadcast it on the soil surface. It should be concentrated near the roots by hole application or band application, followed by deep soil covering, to improve fertilizer use efficiency and prevent seedling burn.

2) Drain water and irrigate in time to prevent waterlogging and drought. Throughout the entire growth period of corn, the seedling stage is drought-tolerant but afraid of waterlogging. When rainstorm water accumulates, drain it promptly to prevent bud waterlogging and seedling waterlogging. From the booting to grain-filling stage, the demand for water is high, and corn is relatively tolerant of waterlogging but cannot lack water. If drought occurs, irrigate in time. One to two irrigations during this period can greatly increase corn yield.

3) Strengthen field management to prevent lodging and yield loss. Lodging, especially in the middle and late stages, is a major factor limiting corn yield increases. On the basis of measures such as planting density-tolerant and lodging-resistant varieties, rational close planting, rational fertilization, intertillage and earthing up, and timely removal of small, weak, and empty plants, if a field is found to have excessive density and a serious risk of lodging, plant growth regulators can be sprayed in advance, such as spraying a 200-fold solution of 50% chlormequat aqueous solution before the booting stage to prevent it.

4) Do a good job in pest and disease control to prevent pest and disease damage. The main diseases in summer corn areas are leaf spot disease, stalk rot (bacterial wilt) disease, and dwarf mosaic disease. The main insect pests are corn borer, armyworm, cotton bollworm, aphids, underground pests, thrips, and so on. All localities should strengthen prevention and control through forecasting and prediction.

5) Harvest at the proper time to ensure quality and quantity. When corn plants mature normally, the husks gradually turn pale, dry, and loose, the “milk line” of the kernels disappears, a black layer forms at the base, and the kernels show their characteristic luster. The moisture content is generally about 30%. At present, the widespread problem is harvesting too early, with relatively high moisture content, low test weight, many moldy and broken kernels, and poor commercial quality, which affects both yield and quality. Wait until the corn is fully mature, at least until the ears have completely turned pale, before harvesting. Properly delayed harvest helps increase corn yield and improve quality. At the same time, it is necessary to properly manage the relationship with promptly clearing the field and planting wheat.