(1) Apples and other fruit thinning apples
Pears and other fruit trees, the number of flowers and fruits in the big year is too large, but the fruit is very small in the next year, and it even takes two or three years to restore the fruit, resulting in the phenomenon of big and small years. In the big year, under the premise of ensuring fruit setting, chemical thinning of excessive flowers and fruits is carried out to make the load suitable and the layout reasonable, thereby reducing the excessive consumption of tree nutrients. This has a significant effect on overcoming large and small annual results, improving fruit quality and preventing tree vigor from weakening.
① Apple
Guoguang, Jinguan, Qinguan and other varieties start to drop petals 5 ~ 10d, spray 40mg/kg naphthalene acetic acid, and spray the crown until it does not drip. About 14 days after the flowering of Jinguan, Cockscomb and other varieties, spray 10mg/kg of tea acetic acid + 200mg/kg ethephon and 3000 times of 6501 spreading agent, or spray 300mg/kg of ethephon in the blooming stage of flower buds, and spray 20mg/kg of ethephon around 10 days after the petals start to fall. kg naphthalene acetic acid. Golden crown varieties can also be sprayed with 10-40mg/kg naphthalene acetic acid 14 days after flowering, or 10mg/kg naphthalene acetic acid + 750mg/kg carbaryl (carbaryl) about 10 days after the petals start to fall. 10 days after the flowering of Guoguang varieties, spray 20-40 mg/kg naphthalene acetic acid, or spray 300 mg/kg ethephon in the bud expansion stage, and spray 20 mg/kg naphthalene acetic acid (or add 300 mg/kg ethephon) 10 days after flowering. The use of naphthalene acetic acid for flower thinning and fruit thinning in apples is mainly used for late-maturing varieties, and early-maturing varieties are not suitable for use because they are prone to phytotoxicity.
②Pear
Ya pear is sprayed with 40mg/kg sodium naphthalene acetate during the full bloom period, which can reduce the fruit set rate by 13% to 25%. Qiubai pears were sprayed with 20 mg/kg naphthalene acetic acid 7-14 days after full bloom, and the number of inflorescences was reduced by 33.59%. When 90% of Jingaisu and Tianshengfuli were in bloom, sprayed with 30mg/kg naphthalene acetic acid, the inflorescence fruit setting rate was reduced by 40.7% and 21.7% compared with the control. decreased by 28.9% and 34.3%.
③Peach
Okubo, spray 20～40mg/kg naphthalene acetic acid in full bloom. Peach, in full bloom and two weeks after flowering, spray 40-60mg/kg naphthalene acetic acid each.
④Wenzhou mandarin orange
30d after the full bloom period, when the fruit diameter is less than 2cm, spray 200-300mg/kg.
⑤Persimmon
10～15d after full bloom, spray 10～20mg/kg.
(2) Prevent flowers and fruits from falling before harvest
①Apples, pears
5～21d before harvest, spray the whole plant with 5～20mg/kg naphthalene acetic acid once to prevent fruit drop before harvest. After 2-3 days of using naphthalene acetic acid for apples, the fruit drop is reduced, and the effect is obvious in 5-6 days. According to local production practices, a few days before the apples fall, usually 30-40d and 20d before harvesting, the wine can be sprayed twice with naphthalene acetic acid with a concentration of 20-40mg/kg, focusing on the fruiting parts of the tree, and spraying wet No dripping is the degree, the first time the concentration is lower, the second time is slightly higher. According to the test, within the effective concentration range, increasing the use concentration does not increase the effect accordingly. If the concentration of naphthalene acetic acid is too high, it will cause phytotoxicity. If it exceeds 60mg/kg, the leaves will wilt and even fall off. However, according to reports, the concentration of naphthalene acetic acid used in ruby apples should be increased to 60-80 mg/kg. When spraying, focus on the fruit and stalk, and more on the inner fruit and the lower fruit.
② Citrus
15 days before harvesting, spraying the stalk of the fruit with 40~60mg/kg solution can prevent the fruit from falling before harvest and increase the yield.
③Shaguo
The maturity is very inconsistent, and the fruit drop before harvest is particularly serious, generally as high as 50% to 70%, which seriously affects the yield and quality of sand fruit. According to experiments, spraying 30-50mg/kg of naphthalene acetic acid on the whole plant about 20 years before the normal harvest of sand fruit can reduce pre-harvest fruit drop by 26% to 46%. Fruit coloring, red fruit rate
up to 71%, an increase of 31% compared with the control.
④ Chili
Peppers have higher requirements on temperature when they bloom and bear fruit. In the early stage of pepper growth, the temperature is lower than 15 °C, the later temperature is higher than 20 °C, and under adverse environmental conditions such as insufficient light and drought, or under excessive fertilizer and water, planting too densely, branches and leaves are leggy, etc. , will cause a lot of flower drop, usually up to 20% to 40%, seriously affecting the early yield and total yield of pepper. The use of phenolic plant growth regulators in production, such as 2,4-D or p-chlorophenoxyacetic acid, can reduce flower drop, but it is very labor-intensive. If the fruit spraying method is used, phytotoxicity will occur. In this regard, Zhejiang Agricultural University conducted a study on the application of plant growth regulators to prevent pepper from falling, and the results showed that the use of naphthalene Z acid had the best effect and was safer.
Zhejiang Agricultural University conducted a test on the hybrid pepper of Hangzhou chicken feet × Qimen sweet pepper, and sprayed flowers with 50mg/kg naphthalene acetic acid solution during the flowering period, sprayed once every 7 to 10 days, and sprayed 4 to 5 times before and after. Significantly reduce flower drop, improve fruit set rate, promote fruit growth, increase fruit number and fruit weight. The previous output increased by 29.2%, and the total output increased by 20.4%, reaching extremely significant and significant levels, respectively. It has been observed that spraying naphthalene acetic acid on peppers can make the leaves darker, prolong the lifespan of leaves, reduce the incidence of pepper mosaic disease, and enhance disease resistance and stress resistance. At the same time, the test also pointed out that under the appropriate concentration, spraying pepper with naphthalene acetic acid will not cause phytotoxicity, which is safer than spraying with 2,4-drop or p-chlorophenoxyacetic acid, and improves the work efficiency by 10 times compared with soaking. Promote the application in production. However, it is not advisable to handle the preserved peppers, because it will have a certain impact on the formation, development and yield of pepper seeds.
⑤ Pumpkin
Coat the ovary with 5-20mg/kg liquid medicine during flowering, which can improve the fruit set rate.
⑥Watermelon
When the female flowers first bloom, dipping or spraying the flowers with 20-30mg/kg liquid medicine can improve the fruit setting rate.
