Detailed Explanation of Key Points for High-Quality Cultivation Techniques of Huanghuali (Asian Pear)

Huanghuali pears produced with traditional techniques have poor quality and low economic returns. To achieve high quality, high yield, and high returns for Huanghuali pears, the following cultivation techniques must be implemented:

1. Change the traditional pruning and training method, converting the lateral central-leader form to the natural open-center form. Remove the central leader of the pear tree, leaving only three main scaffold branches, similar to the training form of peach trees. Practice has proven that through this simple measure, apical dominance is weakened, the scaffold branches become noticeably thicker, increasing by 3 5 cm compared with ordinary production orchards, and the extended branches of the main limbs reach over 2 m, expanding the canopy and increasing the fruiting area in the second year. Also strengthen summer care: in May, promptly remove the weak slender branches in the lower part, overlapping forked branches, dead branches, and upright water sprouts in the upper part, reducing consumption by useless branches and thereby promoting fruit enlargement.

2. Change the traditional topdressing method. Control nitrogen fertilizer and increase phosphorus and potassium fertilizer. Traditional fertilization methods have long paid little attention to fertilizer ratios and often mainly apply nitrogen fertilizer, resulting in vigorous new shoot growth, blocked nutrient accumulation in the fruit, poor development, and small fruit shape. During the fruit enlargement period, nitrogen fertilizer should be controlled and phosphorus and potassium fertilizer heavily applied. Mainly apply the Chunyuan fertilizer series products produced in Taiwan, China. In addition to the three major elements, they contain high amounts of amino acids and trace elements that can be absorbed and utilized by plants. Apply once about every 10 days at a concentration of 800-1000 times. After application, chlorophyll content increases and photosynthetic efficiency is improved.

3. Change the pesticide application method, and strictly control the use of emulsifiable concentrate pesticides before bagging. In the past, pear orchards paid little attention to pesticide application methods during the young fruit stage, applying any pesticide as long as it had disease and pest control effects, and mistakenly believed that the rust spots on the fruit surface of green-skinned fruit were caused by the inherent characteristics of the variety. However, high-quality and high-yield cultivation techniques require great attention to method and effect in pesticide use. It is believed that the fruit rust occurring on green-skinned fruit is not a varietal characteristic, but rather phytotoxicity caused by long-term use of emulsifiable concentrates. Especially before bagging, emulsifiable concentrate pesticides must not be sprayed; using water-based and powder formulations can noticeably control the occurrence of fruit rust spots. For green-skinned pears, strictly controlling the use of emulsifiable concentrates combined with bagging produces "Cuiguan" and "Xinshiji" pear fruits that are smooth and glossy with a light yellow color, and appearance quality is noticeably improved.

4. Change the pear fruit bagging method. In the past, many orchards in Zhejiang, China once used newspaper bags, which had a certain effect on disease and pest control, but the fruit appearance changed little. In orchards without bagging, pear appearance color was poor, and the rate of diseased and insect-damaged fruit reached 15 20%, especially with heavier damage from ring rot and fruit-sucking noctuid moths. Bagging can not only prevent diseases and pests and improve fruit appearance quality, but also overcome pesticide contamination, making it a pollution-free green fruit. The method adopted is: 20 days after petal fall (when young fruits are the size of broad beans), first bag pesticide-sensitive green-skinned fruits ("Cuiguan", "Xinshiji", etc.) with small white bags (10 cm long, 7.5 cm wide); 30 days after petal fall (when young fruits are the size of table tennis balls), put double-layer fruit bags over the small bags. For yellow-skinned fruits, use double-layer fruit bags or single-layer fruit bags. All paper bags are made of kraft paper, which has strong toughness and can withstand wind, sun, and rain. Tests show that in the Zhejiang, China region, where summers are humid and high temperatures last for a long time, it is preferable to choose three-layer bags with white outer and inner layers and a black middle layer, or double-layer bags with a white (or brownish-yellow) outer layer and a black inner layer. For yellow-skinned pears, brownish-yellow single-layer bags can also achieve relatively good results. Through the above bagging method, the surface of green-skinned fruit appears yellow or light green, clean and attractive, becoming a market favorite and comparable to Japanese crystal pears. The surface of Huanghuali pear fruit appears light yellow, without rust spots and without disease or pest damage, and fruit weight reaches over 300 g.

5. Change the habit of ground weeding. Weeding should be adapted to local conditions and timing, grasping both ends and letting go of the middle. That is, weed in the early growth stage of the pear orchard and after harvest, but one month before harvest, which is the peak period of fruit enlargement and also a time of high temperature and severe heat, weeding is not suitable. This can play a role in preserving water and fertilizer and lowering temperature.

6. Change the traditional habit of early harvesting and harvest at the proper time. Local fruit growers harvest Huanghuali pears when they are 60% ripe. Because maturity is insufficient, the fruit flavor is poor, and because of large-scale market supply, the price is only 1.6-2 yuan per kg, resulting in reduced economic income. Harvesting should be insisted upon when fully ripe, about 20 days later than before. According to estimates, in the half month before harvest, the fruit can gain 5-10 g per day. When Huanghuali pears are harvested at 80% ripe, they are sweet, juicy, and fine and crisp in texture, becoming an excellent product for the market, with sugar content increased by 2-3 degrees.