Leaf relationship Flower Bud and Spring shoot how to protect the leaves of Citrus in Winter

Citrus leaves are important organs for the production and storage of organic matter. Winter is the key season for citrus leaves to accumulate nutrients, which is related to flower bud differentiation and the growth and development of spring shoots in the following year. If there are more overwintering leaves, there will be more flowers in the following year, and the fruit setting rate will be high. Therefore, protecting leaves in winter is an important issue in citrus production.

Measures for protecting leaves of citrus in winter

First, protect the root system: the citrus root system is sensitive to external conditions, and the adverse environmental conditions are easy to damage the root system. Deep ploughing and loosening soil can play an effective protective role, so that the tree grows well and the tree is vigorous, but it is not suitable to cut off the root too much, and it is advisable not to damage the large root system above 1cm, so as not to cause fallen leaves.

Second, the scientific use of fertilizer: the application of fertilizer in winter should not be too thick, do not apply unripe fertilizer, should be combined with soil fertilization. After fruit harvest, fruit picking fertilizer should be applied in time. Because the citrus trees blossom and bear fruit in one year, the tree body consumes more nutrients, fertilizing and replenishing nutrients in order to restore the tree potential, reduce the defoliation in winter and increase the flower bud differentiation. Fertilization should be mainly organic fertilizer, combined with a small amount of nitrogen fertilizer, generally, each adult citrus tree soil miscellaneous fertilizer 60kg 100kg, according to the situation can be applied at the same time 0.25kg 0.3kg urea, there are conditions, but also appropriate amount of phosphorus and potassium fertilizer and some trace element fertilizer. Postharvest application of winter fertilizer should be about 10 days before fruit harvest and no later than the end of December. This fertilization can make the leaves green, glossy, enhance cold resistance and prevent winter defoliation.

Third, control moisture: irrigation is carried out from fruit picking to spring shoot germination to make the soil in a proper dry state, which is not only conducive to flower bud differentiation, but also does not cause leaf shedding. However, if it is too dry, the leaves will curl or even fall off. Therefore, in case of drought, should be timely irrigation, it is appropriate to use rapid irrigation method, must avoid waterlogging time is too long, otherwise it will cause rotten roots, resulting in fallen leaves.

Fourth, prevention and control of diseases and pests: citrus leaves can be harmed by diseases and insect pests all the year round. From December to March of the following year, the tree dormancy is the best period for pest control. 80-fold oil emulsion is used to control mites and scale pests, remove moss and lichens, and has a special effect on bituminous coal disease. Or in winter, spraying 3000 times of the solution to control overwintering generation mites, the effect is also very significant. Such as improper selection of pesticides, excessive dosage, high concentration, etc., will also cause defoliation.

5. Reasonable pruning: pruning can improve the ventilation and light transmission conditions of citrus orchards. After fruit picking or in early spring, the thin branches, disease and insect branches and cross branches in the crown can be cut off, and the long branches can be cut short to protect the leaves in winter.

Extra-root topdressing: use 0.5% urea solution plus 0.3% potassium dihydrogen phosphate solution, or 1% compound fruit fertilizer in winter, plus 10~15ppm2.4-D, spray once every 7 to 10 days, use alternately; spray 0.1-0.2% ferrous sulfate on abnormal autumn shoots turning green and add the same amount of lime. Spraying foliar fertilizer and plant hormone can effectively enhance the photosynthetic function of citrus leaves and reduce defoliation.