When is the best time to spray wheat with three defenses? Can I spray herbicides after March 15th?

in the process of wheat growth, wheat is often attacked by various diseases and pests. If it is not prevented in time, it will lead to serious loss of yield and quality. Therefore, one spray of three defenses is an indispensable and important measure in the process of wheat growth. When is the best time to spray three defenses on wheat? Can I spray herbicides after March 15th?

1. when is the best time to spray wheat with one spray and three defenses?

It is best to spray wheat for three prevention from April 17th to May 15th, because April 17th to May 15th is the key period of wheat growth and the important period of wheat pest control. Taking scientific control measures, spraying pesticides, strengthening field management, rational fertilization and regular inspection of wheat can effectively prevent and control diseases.

In addition to spraying drugs from April 17th to May 15th, the time of one spraying and three prevention varies from place to place. For example, in Northeast China, due to the cold climate in this area, the growth period of wheat is relatively long, and the general spraying time is between late April and early May; In the south, the climate is warmer and the growth period of wheat is shorter, so the general spraying time is between late March and early April.

specifically, the time difference of one spraying and three prevention is mainly affected by climate, soil, plant diseases and insect pests and geographical factors. Before spraying, it is necessary to choose the best spraying time according to the local actual situation, use different chemicals in different time periods, and pay attention to spraying according to the correct dosage.

spraying pesticides once is the most important control measure during the wheat growth period. During this period, there are many diseases and insect pests in wheat, and spraying drugs can effectively control the occurrence and spread of diseases and insect pests. Common wheat diseases and insect pests include powdery mildew, scab, aphid, leaf spot and so on. According to different diseases and insect pests, choose corresponding pesticides to spray.

Three prevention, that is, three aspects of pest prevention measures: prevention, monitoring and treatment. Prevention refers to reducing the probability of occurrence of diseases and insect pests by selecting varieties resistant to diseases and insect pests, controlling the field climate and environment, and applying fertilizers scientifically. Monitoring refers to observing and discovering pests and diseases in time to avoid large-scale outbreaks of pests and diseases. Control refers to taking corresponding control measures to control the further development of pests and diseases when pests and diseases have occurred.

second, can wheat be sprayed with herbicides after March 15th?

Wheat can't be sprayed with herbicides after March 15th, for the following reasons:

1. Wheat needs sufficient light and temperature at the initial stage of growth, but after March 15th, the temperature begins to warm up, and the temperature difference between day and night becomes larger. Spraying herbicides will destroy the growing environment of wheat, slow down the growth rate of wheat, and even cause damage to leaves, thus affecting the yield and quality of wheat.

2. When wheat enters the middle and late March, it has entered the jointing stage and started to grow and heading. At this time, the use of herbicides will do great harm to wheat. The jointing stage is an important stage of wheat growth, and the use of herbicides will seriously affect the growth of wheat, leading to the reduction of wheat yield, and even the phenomenon of spikelets, empty ears and small grains, thus causing economic losses of wheat.

3. After wheat entered the jointing stage after March 15th, the soil moisture gradually increased, and the growth rate of wheat gradually accelerated. The use of herbicides would leave weeds and chemical substances in the soil, which would have adverse effects on the growth environment of wheat and even lead to its death.

conclusion: the best time for spraying three prevention measures on wheat is from April 17th to May 15th, and the specific time is mainly affected by climate, soil, plant diseases and insect pests, geographical factors, etc. However, it is not allowed to spray herbicides on wheat after March 15th, because the wheat has entered the jointing stage in the middle and late March, and spraying herbicides will be detrimental to the growth of wheat.