Early defoliation of apricot trees can be effectively controlled with EM original solution

Editor's note: Zhou Jinlong from Dongniuzhuang Village, Guangzong County called to report that 4 years ago he introduced the “Zaohe” apricot variety from Julu County, and since last year he has seen defoliation during the growing season, and this year it is even more serious, with basically no fruit setting. He asked whether there is a good method to control early defoliation of apricot trees. The following article by Zheng Yi may be helpful to Zhou Jinlong and to fruit growers facing similar problems.

Hengshui City currently has 23,000 mu of apricot trees, with main varieties including Luotuo Huang, Zhonghua Bai Xing, Jintaiyang, and Chuanzhihong, and the income from fruit sales occupies an important position in the rural economy of our city. However, every year after the fruit is harvested, the leaves begin to fall, and on heavily bearing, weak trees the leaves have basically all fallen by late July, with Zhonghua Bai Xing being the most severely affected by early defoliation among the varieties. From 2002 to 2004, the author used EM original solution (a compound microbial preparation produced by Jiangxi Nanchang Tianyi Biotechnology Development Co., Ltd.) to control early defoliation of apricot trees and achieved obvious results. The rate of defoliated trees in the orchard dropped from 74.4% in 2002 to 11.5% in 2004; the leaf retention rate rose from 34.2% in 2002 to 86.6% in 2004. The trial site was set up in a 20-mu apricot orchard in Zhouyan Village, Dengzhuang Township, Taocheng District. The orchard is on flat land with heavy loam soil, relatively clayey texture, deep soil layer, and irrigation available. The varieties include Zhonghua Bai Xing, Jintaiyang, Luotuo Huang, and Chuanzhihong. Except for Jintaiyang apricot, which are 4-year-old trees, the other varieties are all 10-year-old trees. The specific methods are as follows:

1. Use EM original solution to make fermented compost and apply it into the soil as base fertilizer. Before winter arrives, make the compost half a month in advance. Organic fertilizer (well-rotted chicken manure, pig manure, and other poultry and livestock manure), EM original solution, and brown sugar are prepared in a ratio of 500-1000:1:1, and the amount of water used is 30%-35% of the total amount of organic fertilizer (increase or decrease the water amount depending on whether the organic fertilizer is dry or wet). When preparing, first melt the brown sugar, pour it into the water, then add the EM original solution, and then mix and stir evenly with the organic fertilizer, pile it up and compact it, seal it with plastic film, and ferment anaerobically. After about half a month, if a wine starter aroma is given off or white or red mycelia appear, it indicates successful fermentation and it can be used. Alternatively, dig a large pit in the ground, first spray the bottom of the pit and the four walls with a 500-1000 times diluted EM original solution, then spray a 500-times diluted EM original solution once for each layer of organic fertilizer placed (20 cm thick), until the large pit is filled, then cover with soil and tread it firm. After two weeks of fermentation, once there is a wine starter aroma or white and red mycelia appear, it can be used. During fermentation, if the temperature reaches above 50°C, it should be turned, and after cooling down it should be sealed again for fermentation, so as to avoid destroying the effective substances.

2. Foliar fertilization. Starting after fruit harvest, spray a 1000-times EM original solution once every 10-15 days, using it 3-4 times throughout the year, and it can also be used alternately with 0.3%-0.4% urea + 0.3%-0.4% potassium dihydrogen phosphate solution.

Precautions: Whether EM original solution is used as base fertilizer or foliar fertilizer in the same year, the effect is not very obvious, and it is necessary to wait until the next year or the third year to clearly see the results; for summer foliar fertilization, the best effect is before 10 a.m. or after 5 p.m., and it must not be used during the high-temperature period at noon.