What are the remedial measures after lychee trees suffer frost damage?
1. Pruning
When leaves die and the top twigs turn brown and necrotic while the lower branches and leaves are not frozen to death, the affected dry, brown branches and leaves should be removed in time to prevent the spread of frost damage and to avoid increasing the burden on the plant. Proper pruning can also stimulate vegetative growth, but if the leaves are dry while the branches are not frost-damaged, only the dry leaves should be cut off and the branches retained. If the bark of frost-damaged branches has not split, they should be wrapped immediately with straw or plastic film. If an young tree has been completely frozen to death above the main trunk, the dead portion should be sawed off and the remaining trunk and branches wrapped immediately with straw or plastic film to prevent the bark from losing water, splitting and becoming necrotic.
2. Fertilization
Apply supplementary fertilizer in time; applying about 1 tonne of diluted urine water per mu is beneficial for root growth and accelerates the plant's recovery. During the flower bud differentiation stage, an appropriate additional application of flower-strengthening fertilizer is also needed. For foliar feeding, promptly spray foliar fertilizers such as Shengduosu, Plant Power 2003, potassium dihydrogen phosphate, Lufenwei, Aiduoshou, and compound nucleotides, spraying once every 10-15 days to increase nutrition, promote root growth and promote flower formation.
3. Drainage and irrigation
After frost damage occurs, pay attention to drainage and irrigation to promote root growth. If the soil is dry, irrigate in time to accelerate the plant's recovery. If an young tree has been completely frozen to death above the main trunk, the tree disc should also be covered to keep it warm and moist, so as to encourage it to send out new shoots again from the base of the tree and cultivate a new canopy. After rain, loosen the soil in time to improve soil aeration, keep the soil layer loose, and facilitate root extension and growth.