Six measures to protect leaves of growing Citrus in Winter

40~60% of the nutrients in citrus trees are stored in the leaves after they enter dormancy in winter. Therefore, leaf protection in winter is not only beneficial to enhance the cold resistance of trees, promote flower bud differentiation, but also conducive to germination and flowering in the following spring. Leaf protection measures mainly include the following:

1. spray leaf protection

The focus is on red spider control. Red spider is one of the main pests of citrus. There is no obvious diapause period. Red spider is still harmful to citrus in low temperature in winter. It is one of the main reasons for abnormal defoliation of citrus. When the number of red spiders on the leaves exceeds 1 head/leaf, drugs such as acaricide or saomijing can be sprayed.

2. Fertilization and leaf protection

Citrus is short of nutrients after harvest. If fertilizer is not applied in time, some citrus orchards will have leaf curl and wilting. Therefore, spraying fertilizer after citrus fruit picking can keep the leaf color dark green and the tree vigor recovers quickly. The amount of fertilizer sprayed should be adjusted according to the trees.

3. Plant growth regulator leaf protector

Spraying paclobutrazol 500~1000mg on leaves can enhance chlorophyll synthesis in leaves, improve photosynthetic capacity of leaves and prevent leaf senescence. Spraying 2,4-D 10 ~20mg could prevent the formation of defoliation layer and abnormal defoliation.

4. pruning and leaf protection

Mainly through pruning, improve light conditions, promote leaf photosynthesis. Sparse and dense branches, cross branches and overlapping branches shall be pruned according to the requirements of leaving empty and densifying, leaving strong and weak branches, and cutting off excessive long branches, drooping branches and branches with serious diseases and insect pests.

5. Drought and waterlogging prevention

Drought and water shortage can easily lead to drying of roots, decrease of absorption capacity, enhancement of leaf transpiration and leaf falling. Therefore, if drought occurs after winter, ditch irrigation or hole irrigation shall be adopted in time, combined with foliar fertilizer spraying. In case of continuous rain, ditch drainage should be timely.

6. frost protection leaf

After fruit picking, combine with deep soil ploughing, apply heavy fertilizer once, and then cultivate soil to increase soil temperature. Brush or cover tree trunks in early frost.