Key Field Management Techniques for Corn at the Big Trumpet Stage

The big trumpet stage is a critical period for corn growth and development, when both reproductive growth and vegetative growth are vigorous. At the same time, this stage is also a period of high incidence of corn pests and diseases. Field management at this stage should emphasize the “five preventions”:

1. Preventing fertilizer deficiency. The big trumpet stage is the peak period of fertilizer demand, so to prevent nutrients from falling short, fertilizer should generally be applied according to soil fertility and seedling condition, with 30-35 kg of urea per mu applied deep in dug holes, and soil covering after fertilization. For those with good growth, apply appropriately less or delay application; otherwise, apply more and earlier; for those with very poor growth, apply 120-150 g per mu of potassium dihydrogen phosphate or high-efficiency concentrated humic acid liquid fertilizer for 2-3 foliar applications, spraying once every 5-7 days.

2. Preventing lodging. At this stage, 2-3 cultivations and hillings should be carried out, with a total hilling height of 8-10 cm. Spraying 30 ml per mu of corn stem-strengthening agent or Weitaling mixed with 30-40 kg of water can reduce corn plant height and ear height by 15%-20%, which not only prevents lodging but can also increase corn yield per unit area by more than 15%. Uniform spraying on the leaf surface is required, with no repeated spraying and no missed spraying; if rain occurs within 8 hours after spraying, re-spray with a reduced amount as appropriate.

3. Preventing excessive tillering. During the big trumpet stage, corn grows vigorously and often produces tillers, causing nutrient loss; these should be removed in time to promote high corn yield.

4. Preventing pests and diseases. The main diseases in the middle and late stages of corn include large and small leaf spot disease, top rot, and bacterial wilt, which should be prevented early. Generally, control should be advanced to the big trumpet stage, applying a mixed treatment once per mu of 150 g of 70% mancozeb, 200 g of 50% carbendazim, and 100 g of 75% chlorothalonil. The main pests include corn borer, armyworm, and cotton bollworm; use 150 g of phoxim or omethoate mixed with water and pour it into the whorl, or broadcast 1.5-2 kg of phorate granules.

5. Preventing drought. Water promptly in case of drought. Watering can also lower field temperature, which is beneficial for corn flowering and pollination and helps prevent bald tips. In this way, high yield and high efficiency of corn can be achieved.