Key Points and Methods of Thinning Fruit on Sweet Cherry Trees
Technical management of sweet cherry trees after harvest is very important, because at this time the tree has gone through the earlier processes of leaf expansion, shoot growth, flowering, fruit set and fruit growth and development, consuming a large amount of the nutrients stored in the tree, and after fruit harvest it enters the nutrient accumulation stage of photosynthesis. Management during this period [affects] yield. Its techniques...
(1) Thinning requirements: The suitable fruit set rate for sweet cherry is 15-20% of the number of flowers, and the maximum fruit set rate must not exceed 50% of the number of flowers. The leaf-to-fruit ratio is 4-5, with a minimum of 3.(2) Timing and method of fruit thinning: It is generally carried out after the second physiological fruit drop (pit-hardening stage) of cherry, mainly for trees in the late full-bearing stage, that is, starting 16 days after flowering, fruit with a diameter of less than 10 mm can be thinned. Each flower-bud spur retains 3-4 fruits; remove small fruits, twin fruits, deformed fruits and excess fruits on weak shoots, and also remove drooping fruits that are not easily reached by light and color poorly, while retaining large horizontal and upward-facing fruits. Through fruit thinning, the tree's load can be further adjusted, promoting fruit enlargement, improving fruit coloring and sugar content, and improving quality.