Key points for the management of citrus orchards in winter

The key points for the management of citrus orchards in winter are as follows:

The main results are as follows: 1. with the decrease of air temperature, citrus fruit trees have entered a relatively dormant period. in the citrus producing areas of the south subtropical zone with relatively high temperature, young citrus trees will sprout sporadic winter shoots, which are not easy to mature and have no use value. it should be erased in time to avoid the consumption of nutrients and is not conducive to the accumulation of nutrients.

2. Timely harvest and reasonable storage

(1) timely harvest: the late-maturing varieties of citrus fruits in December have matured and entered the harvest period. at this time, they should be harvested in batches according to the maturity and the color, size, weight and soluble solids of the fruit. Huang Liuqing can be harvested first, divided into 2-3 times, graded harvest, each tree is harvested according to the three grades of large, medium and small, and harvested in batches according to the quantity on the market, such as as storage fruit. It can be harvested when the fruit is 7-8 ripe and fresh food is harvested when 8-9 is ripe.

(2) reasonable storage: fruit harvesting must be carried out after dry dew in sunny days. In order to avoid fruit trauma, the method of "one fruit and two shears" should be adopted, that is, the fruit should be cut 1-2 cm away from the pedicel, and then the pedicel should be cut flat, cut lightly and placed lightly. After harvest, the injured, diseased and insect fruits are selected, packed and sold according to their size. The storage fruit should be treated with medicine immediately after harvest, and the solution should be filtered in a cool place. After pre-storage and sweating, the fruit should be packed with a single film, and then stored in storage.

3. Fertilizer and water management is suitable for fruit-picking fertilizer: late-maturing varieties should apply fruit-picking fertilizer before fruit harvest, so as to promote the restoration of tree potential and flower bud differentiation. After fruit harvest, 0.3% urea + 0.3% potassium dihydrogen phosphate should be sprayed for extra-root topdressing and irrigation to restore tree potential and protect leaves for the winter. Enhance the ability to resist cold. The old and weak trees should apply hydrogen fertilizer properly, and the young trees should apply more phosphorus and potassium fertilizer, which should be combined with deep turning and pressing green to improve soil. Water should be properly controlled before fruit picking to facilitate fruit storage and promote flower bud differentiation. However, in winter arid areas, we should pay attention to proper irrigation, which is beneficial to root growth, promote the restoration of tree potential and reduce winter defoliation, and appropriate irrigation in low temperature areas to improve plant cold resistance.

4. Pruning the garden after harvest, pruning disease and insect branches, withered branches, cross branches and overlapping branches. In order to reduce overwintering diseases and insect pests, the pruned disease and insect branches and litter should be burned centrally. Pruning should be carried out reasonably according to the growth characteristics of citrus, and the strong branches under the top should be removed from the base of the big branches in the form of "open skylight", and the shade branches and overlapping branches inside the crown should be thinned. Retract the branches that block the sun between the rows and outside the crown, so as to keep the tree and orchard ventilated and transparent.

5. the tree potential is basically restored after fruit harvest, and timely spraying is required to control winter diseases and insect pests, and attention should be paid to the uniform, comprehensive and thorough spraying of the whole tree; inside and outside the crown, trunk, main branches, backbone branches and branches at all levels should be sprayed in place, only in this way can the overwintering adults, larvae and eggs be eliminated. The medicaments used are 0.8-1 pomethyl sulfide mixture, 10-15 prednisone mixture and 99% enemy machine oil emulsion, 80-1000 times and so on.

6. Deep ploughing, soil cultivation and root protection of citrus orchards should be carried out before frost, with a depth of about 30 cm, shallower within the crown drip line and deeper outside the drip line. Most of the orchards in South China are acid red-yellow loam with a pH value between 5 and 6.5. Combined with the application of lime (100 kg lime per mu), it can neutralize the acidity of the soil slope, and lime can eliminate overwintering diseases and insect pests. After turning, the tree plate should be arranged in the rhizosphere; cultivate 10 cm of soil and cover straw, straw and hay to protect the root system and enhance the ability to withstand cold and winter.