When is the best sowing date for wheat?

The planting time of winter wheat depends on varieties and regions. In the vast plain areas north of the Yangtze River and south of the Huaihe River, 65,438+00 days, ***20 days are suitable before and after the first frost, and other sowing dates are later, so the sowing amount is better, because the late sowing is not good. How is the best sowing date of winter wheat calculated? Usually, the sowing date is determined by the variety, that is, the spikelet differentiation of winter wheat does not exceed the early two ridges before winter. Generally, the accumulated temperature of winter varieties needs > > 0℃590℃, semi-winter varieties need 490℃ and spring varieties need 390℃. ..

Accumulated temperature method before winter. The accumulated temperature of wheat from sowing to emergence plus the accumulated temperature from emergence to stop growing before winter is the accumulated temperature of wheat before winter. The accumulated temperature of wheat from sowing to emergence is about 65438 020℃, and the accumulated temperature of each leaf needs 75℃ before winter. Generally, spring wheat is sown from March to April, and winter wheat is sown in August to165438+1October. However, different regions have their suitable sowing dates. Winter wheat: Sow in September and June, 65438+ 10, and harvest in April and May of the following year (mainly in the south of the Great Wall). Spring wheat: Sow after the Spring Festival.

How is the best sowing date of winter wheat calculated? Usually, the sowing date is determined by the variety, that is, the spikelet differentiation of winter wheat does not exceed the early two ridges before winter. Generally, the accumulated temperature needs to be > > 0℃590℃ for winter varieties, 490℃ for semi-winter varieties and 390℃ for spring varieties ... The most suitable sowing temperature for winter wheat is that the daily average temperature decreases steadily to 15- 17℃. There is a saying in the agricultural proverb: "The autumnal equinox is early, the first frost is late, and the cold dew is planting wheat at that time." As far as the current climatic conditions are concerned, if we sow before and after the cold dew, it is obvious that the temperature is on the high side, and sowing at this time is easy to cause prosperity before winter.

Make full use of light and heat and water and soil resources to achieve the goal of cultivating strong seedlings before winter. The method of determining the suitable sowing date is to preliminarily determine the theoretical suitable sowing date according to the seedling age index of the variety before winter and the requirements for the accumulated temperature before winter, and then adjust measures to local conditions according to the development characteristics of the variety and the solar terms of wheat planting.