Cold-proof and frost-proof technology of rape in early spring

First, clear ditches and cultivate soil to prevent waterlogging. Clean up the "three ditches" in time to reduce the humidity in the field and prevent the occurrence of waterlogging. Combined with clearing ditches, the soil and roots of the fields that are too prosperous or too weak are cultivated to reduce the damage of freezing injury to the root system.

Second, remove frozen moss (leaves) to reduce losses. It is suggested that the early flowering and early moss of a small number of rape should be removed and cut off in time. For the frozen early moss and early flowering rape, the frozen moss should be removed in time on a sunny day to promote the growth of some branches of rapeseed and make up for the loss of freezing injury. The frozen moss should be removed from about 2 cm below the dead stem, cut with scissors or with a sickle bevel, and remove the frostbitten leaves with obvious water stains in time to prevent frostbite from involving the whole plant. Leaves that are obviously white or dry should be removed in time. The frozen moss and frozen leaves removed should be cleaned up and should not be left in the rape field. Removal of frozen moss and removal of dead leaves should not be carried out when the dew is not dry, so as not to cause wound decay.

Third, applying topdressing fertilizer to promote recovery. After the rape was frozen, the leaves and roots were damaged to varying degrees, so nutrition must be replenished in time. After the frozen moss is removed, the field should be topdressing 5-7 kg urea per mu or a considerable amount of compound fertilizer to promote branching growth. The rape with frozen leaves is topdressing 3-5 kg urea or equivalent compound fertilizer per mu, and the field with poor growth can appropriately increase the amount of topdressing fertilizer to make it grow again as soon as possible. On the basis of topdressing nitrogen fertilizer, an appropriate amount of potassium fertilizer should be applied, which can be applied with 3kg potassium chloride per mu, or about 500g potassium dihydrogen phosphate is sprayed on the roots in combination with pest control, so as to enhance the cold resistance of the plant and promote strong seed filling. In addition, about 50 kg of 0.1%-0.2% boron fertilizer solution was sprayed per mu of leaves to promote flower bud differentiation.

Fourth, prevent and control diseases and pests to ensure a bumper harvest. The wound of rape increases after freezing, and it is more likely to be infected with Sclerotinia sclerotiorum and other diseases. it is necessary to strengthen the prediction of diseases and insect pests, pay close attention to the occurrence of the disease, and timely spray Sclerotinia, thiophanate methyl and mancozeb to control.