Detailed Explanation of Key Points for Autumn Management Techniques of Citrus

1. Heavy application of fruit-swelling fertilizer: its fertilizer amount accounts for about 30% of the annual fertilizer amount, mainly decomposed organic fertilizer. Dig an arc-shaped ditch 20-30 cm deep and 20 cm wide between rows at 50-100 cm from the main trunk. For large trees, apply 2.5 kg of cake fertilizer and 50 kg of decomposed pig or cattle pen manure or human excrement and urine per tree; for small trees, apply 1.5 kg of cake fertilizer and 25 kg of decomposed pig or cattle pen manure or human excrement and urine per tree, then cover with soil and irrigate. In addition, spray the canopy with foliar fertilizer 2-3 times, using a mixture of 0.3% urea solution plus 0.2% potassium dihydrogen phosphate, spraying once every 10-15 days.

2. Irrigation and drought resistance: from July to September, during the high-temperature and drought season, growth and fruit development both require a large amount of water, so irrigate once about every 10 consecutive days of drought. 1-2 days after irrigation, cultivate once to reduce water evaporation, or cover the soil with weeds and leaves to lower temperature, preserve water and resist drought.

3. Bud wiping and shoot release: producing early and robust autumn shoots is an important foundation for achieving sustained high quality and high yield of citrus trees the following year. Starting from mid-to-late July, wipe out sporadic autumn shoots once every 2-3 days until the low-peak period of citrus leafminer damage in early August (when the base leaves of autumn shoots are damaged and the middle and upper leaves have no insect damage, this is the low-peak period of citrus leafminer damage), then uniformly release early autumn shoots, that is, leave autumn shoots 20-30 cm long and pinch off the tips, and promptly wipe out late autumn shoots. In this way, robust early autumn shoots are cultivated, and citrus leafminer damage is avoided or reduced.

4. Disease and pest control: when autumn shoots grow to 2-3 cm, spray 20% isocarbophos emulsifiable concentrate at 800 times dilution or 40% isocarbophos at 1000-1500 times dilution, or 40% Supracide emulsifiable concentrate at 800-1000 times dilution. This mainly controls citrus leafminer and red spider mite, and also controls rust mite and scale insects. In late August, spray 0.3 degree lime sulfur mixture, mainly to control red spider mite and rust mite, and also to control citrus leafminer. In early September, spray Kelthane at 2000-3000 times dilution, mainly to control rust mite and red spider mite. Use thiophanate at 800 times dilution to control anthracnose, for 2-3 consecutive times, with very good results.