How many leaves does corn have at the large trumpet stage? How to tell
The large trumpet stage of corn is at 11 leaves. At this point the plant has formed about 60%, the tassel has begun floret differentiation, and it is the key period for determining the number of grains per ear, as well as the key period for fertilization. If fertilizer is applied well, the number of grains per ear will increase, and at the same time doing a good job of hilling and soil cultivation, watering, pest and disease control and other management work can promote high yield.
Planting management methods for corn at the large trumpet stage:
1. Topdressing
The large trumpet stage is the period when corn needs the most fertilizer and the greatest fertilizer intensity in its whole life, and topdressing must be strengthened at this stage to prevent fertilizer deficiency. Fertilizer should be applied generally according to soil fertility and seedling condition, using 30-35 kg of urea per mu, dug into pits and applied deeply, with soil covering after application. For corn fields with good growth, it can be applied less or later; otherwise it should be applied more and earlier; for those with very poor growth, 120-150 g of potassium dihydrogen phosphate or high-efficiency concentrated humic acid liquid fertilizer per mu should also be used for 2-3 foliar applications, sprayed once every 5-7 days, with obvious effect.
2. Cultivation and hilling
At the large trumpet stage, corn has strong requirements for nutrients, water, light and oxygen. Cultivation can loosen the soil, improve aeration and the supply of water and fertilizer, thicken the soil layer at the base of the plant, promote root growth, and prevent lodging. At the same time, removing weeds can conserve water and preserve soil moisture, so cultivation is an important measure in the management of corn at the large trumpet stage. Carry out cultivation and hilling at the large trumpet stage; hilling should not be done too early, and the hilling height should be 6-10 cm. After hilling, spray 30-35 kg per mu of corn growth regulator or trinexapac-ethyl mixed with water, which can reduce corn plant height and ear height by 15%-20%, effectively balancing the relationship between vegetative growth and reproductive growth, not only preventing lodging but also increasing corn yield per unit area, generally increasing yield by more than 15%. Spray evenly, with no repeated spraying and no missed spraying. If it rains within 8 hours after spraying, re-spray at a reduced dose as appropriate.
3. Watering
The large trumpet stage of corn coincides with the high-temperature season. The plant's water demand for growth and evaporation increase day by day, and it is the critical period for corn's water demand. Watering can also change the field microclimate, which is beneficial to corn flowering and pollination, improves the seed-setting rate of the ear, and achieves high yield and high efficiency of corn. Generally, water is applied separately at the small trumpet stage and the large trumpet stage. The water amount at the small trumpet stage should be small, and it can be done by opening furrows in alternate rows; at the large trumpet stage the water amount should be sufficient. At the same time, always pay attention to weather conditions, so that water can be drained in waterlogging and irrigated in drought.
4. Pest and disease control
At this stage, corn borer, armyworm, cotton bollworm and large and small leaf blight will occur to varying degrees, and the field should be inspected at any time for pest and disease occurrence. If insect pests occur, use phoxim or decis and the like to make poisoned soil and pour it into the whorl, which gives a good control effect; if diseases occur, use 600-fold Antaison or Junlisha solution + 300-fold potassium dihydrogen phosphate or other foliar fertilizer for foliar spraying, and be sure to spray the solution evenly.
The above is the relevant introduction on how many leaves corn has at the large trumpet stage. I hope it is helpful to everyone.