How to manage wheat in the later stage when spike number has been determined, grain number and grain weight are changeable?

In the late growth stage, the number of spikes has been determined, but the number of grains per spike and grain weight will change if properly managed. Therefore, doing a good job in the late management of wheat is helpful to strive for multi-grain weight and improve the yield of wheat. The key management measures in the later stage of wheat are as follows:

Wheat

1. Timely watering. Wheat at heading and filling stage needs more water, and water consumption accounts for 70% of the total water consumption in the whole growth period. Therefore, it is necessary to timely water according to soil moisture and wheat seedlings, so that the soil moisture of the wheat field can be kept at 65% to 80% of the maximum water holding capacity in the field. Some places also irrigate wheat yellow water that has a certain effect on resisting dry and hot wind, and the amount of water should be appropriate, especially wheat before maturity, so as not to cause wheat root system to suffocate and rot, lead to withering and forcing ripening, and reduce grain weight. In a normal year, watering is usually stopped 10-15 days before the wheat harvest.

2. Reasonable topdressing. For the fields with poor soil fertility and wheat leaves tend to yellowing before and after heading, no more than 5 kg of nitrogen fertilizer per mu can be applied combined with watering. In addition, foliar fertilizer sprayed outside the root, such as potassium dihydrogen phosphate, Fengchanling and so on, the effect is also good.

3. Prevention and control of diseases and pests. There are many diseases and insect pests in wheat in the late growth stage, so it is necessary to control them in time. If there is sheath blight, use 5% Jingangangmycin water agent per mu; if there is powdery mildew or rust, use 20% trimethoprim EC 75 ml per mu; eliminate aphids, use 10% imidacloprid wettable powder 15 grams per mu; control scab, when the flowering plant rate of wheat reaches 10%, use 40% carbendazim glue suspension 3 taels per mu. Adults of trematodes were sprayed with 50% phoxim EC 50 ml or 25 ml pyrethrin EC per mu and sprayed with water. All the above agents are sprayed with 50 kg of water after dry dew on a sunny day. If there is rain within 8 hours after spraying, supplementary spraying should be carried out in time.

4. harvest at the right time. The grain weight of wheat increased by about 1 to 2 grams per day from grain filling to the end of wax ripening at the highest point. At the end of wax ripening, harvest in time. If the harvest is too late, the grain becomes dehydrated and hardened, the glume is loose, and it is easy to drop grains; the ear stem becomes brittle and easy to drop off the ear; the varieties with short post-ripening period will sprout in the event of rain.