Fruit thinning plays an important role in the growth of grapes, and it is the key to determine whether the ear shape of grapes is beautiful, the particle size and the chromaticity are good or bad. The fruit thinning period should be carried out immediately after fruit setting and when the size of fruit particles is clearly distinguished. According to the fruit setting rate, the ear with high fruit setting rate should be sparse, and the ear with low fruit setting rate should be sparse.
When thinning fruit, first thin small fruit, deformed fruit, diseased fruit, cracked fruit and rusted fruit, then thin small ears to cover them tightly below, and finally thin fruit. When thinning fruit, we should first thin the fruit inward to make the fruit as loose as possible, so that more than one-third of the fruit surface is exposed to direct light during the expansion period and maturity period. After the ear is tapered, the shape of the ear is conical.
Causes and basis of fruit thinning
Grape ears are big and have many grains. Under normal circumstances, the number of flowers per grape inflorescence can reach 200~2000. The suitable weight of each bunch of grape commercial fruit is 500~ 1000g, which depends on the variety characteristics and the single grain weight. Seedless summer black 80~ 120, red globe grape 50~70, sunshine rose 40~80, Hutai No.8 80.
So many flowers, if not artificially thinned, will naturally drop flowers and fruits, which is a natural law and the result of plants adapting to the environment and adjusting themselves according to their own nutritional level.
With so many flowers and fruits, there are often too many fruits and large ears when water and fertilizer are sufficient. Without artificial flower thinning and fruit thinning, it is impossible to produce high-quality standardized commercial fruits. Because of the large amount of fruit set and the increase in consumption this year, trees will be overwhelmed and there will be a phenomenon of big and small years. This is what the masses often say: tired trees.