The greenhouse time of apricot cultivation in protected field

General apricot varieties must undergo a low temperature period of 700 to 1000 hours below 7.2 ℃ in order to break dormancy. Therefore, protected cultivation must be heated up after meeting the low temperature demand of apricot in order to be successful. Early heating apricot trees can not sprout and blossom normally, when serious, it will cause a large number of buds to fall off, irregular florescence, serious flower and fruit drop. The heating time should also be carefully determined according to the low temperature demand of the variety and the weather conditions.

The main results are as follows: 1. The thermal insulation performance of plastic greenhouse is poor, apricot trees must go through dormancy under natural conditions, and the suitable time is from the end of January to early February, which is the heating time. If the weather is abnormal, if there is a warm winter phenomenon, the time of withholding the shed should be postponed appropriately. The plastic greenhouse should be covered with plastic film 15-20 days before the plastic shed to make the ground temperature rise slowly.

2. The holding time of solar greenhouse has better heat preservation performance, which can make apricot trees quickly pass through dormancy, so it is necessary to carry out low temperature treatment to meet its cooling capacity. The solar greenhouse usually begins to buckle from late October to early November (the lowest temperature at night is below 7 ℃), covering plastic film and straw curtains. After the buckle shed, cover the grass curtain before sunrise in the morning and close the vent. In the evening, open the grass curtain and open the vent. When the highest temperature in the shed during the day is kept below 7 ℃, there is no need to open the grass curtain in the evening. As a result, the temperature in the greenhouse can be kept below 7 ℃, which can meet the cooling requirement of apricot in about one month to one and a half months, and pass through the natural dormancy smoothly. The temperature began to rise in the middle and south of Hebei Province in mid-late December, and in the north-central region in the first ten days of December, the solar greenhouse with good thermal insulation performance can be heated up earlier than those with poor thermal insulation performance.