How to grow citrus for high yields? Autumn management is key
Autumn is an important period for citrus fruit enlargement and new shoot growth. Strengthening citrus orchard management can achieve high and stable yields year after year. The techniques are as follows:
Irrigate to preserve heat, and combat drought to preserve heat. In the early stage, irrigate the orchard in the morning and evening. For fruiting trees, each tree should receive no less than l00kg~150kg each time. Using weeds, wormwood stalks, vines, etc. for ground cover can also preserve moisture, combat drought and preserve fruit.
Thin buds to nourish shoots, and girdle to promote flowering. In mid-September, for trees that bear few fruits this year and grow excessively vigorously, use a sharp budding knife to girdle 1-3 complete rings on 2nd to 3rd order branches, deep to the xylem, to promote flower bud differentiation. After girdling, spray once every 20 days or so with 0.2% potassium dihydrogen phosphate and 0.3% urea, plus a 30PPM~40PPM 2,4-D solution, for 3-4 consecutive times, which can prevent leaf drop in winter and spring.
Multiple-head top grafting to replace with superior varieties. In early autumn, for inferior, low-yielding trees under 30 years old with normal tree vigor, carry out multiple-head top grafting to change varieties, developing new varieties such as high-quality navel orange, extra-early-maturing Satsuma mandarin and Kiyomi. Using the “single (double) bud side grafting” method, graft the buds evenly onto upright and slanting branches about 2cm in diameter in the middle and upper part of the canopy. After they survive, cut back the stock in April of the following year.
Forecasting and control of pests and diseases. From August to October, high temperature and high humidity make this the peak period for the occurrence and damage of citrus pests and diseases. Focus on controlling anthracnose, citrus leafminer, rust mite, red spider mite and arrowhead scale, etc. During the autumn shoot flush period, when the new buds are the size of rice grains, spray a mixed solution of 0.5% decamethrin 2000-fold solution plus 20% amobam 1000-fold solution to control citrus leafminer and anthracnose, spraying once every 7-10 days for 4-5 consecutive times. During the summer drought period, when scattered young citrus fruits show “black charcoal” symptoms, immediately use 0.2-0.3 degrees Baume lime sulfur mixture to control 1-2 times; in early to mid-September, during the peak occurrence period of arrowhead scale, when the young scales have hatched to about 50%, spray the canopy with 20% kuaike emulsifiable concentrate or 40% supracide emulsifiable oil 1500-fold solution to control 1-2 times.