How to manage the development period of grape fruit?

How to manage the development period of grape fruit?

The branches are plucked from the heart and sprayed with fertilizer to maintain a good tree appearance. The new shoots basically stopped growing one month after flowering, and the unstopped elderly carried out heart-picking control in order to concentrate nutrition for fruit development. The fully unfolded functional leaves near the branches should remain dark green. Insufficient nitrogen fertilizer, excessive nitrogen fertilizer, excessive shoot growth, excessive growth and rapid expansion of fruit with gibberellin (seedless) will also cause the leaf color to fade, lose green or yellowing near the ear. Urea can be applied to supplement nitrogen. More nitrogen is needed during fruit coloring period, and fierce competition for nitrogen with leaves will lead to leaf yellowing. In order to avoid pollution of fruit surface by foliar spraying during fruit coloring period (except bagging), nitrogen fertilizer can be applied in advance during fruit softening period (before fruit coloring). The good performance of the tree phase is that most of the new shoots stop growing one month after flowering, and the leaves are divided into upper, middle and lower parts, the upper leaves are small, upright, holding water upward, the middle leaves are larger, drooping when the light is strong, and the lower leaves are horizontal to capture light to the maximum.

The soil is fertilized and watered. It is an appropriate time for topdressing nitrogen fertilizer that the leaf color is lighter or is about to fade. If 666. 7m2 target yield 1500kg, when the new shoot growth is weak and the leaf color is light, urea 25 kg; is applied when the new shoot growth is good and the leaf color is normal, while the new shoot growth is strong and the leaf color is thick. It should be applied appropriately according to the change of new shoot growth and leaf color. Carry out water-saving irrigation and maintain a balanced water supply. In sunny days, irrigation is once a week, and the amount of irrigation water is drip irrigation 10 ~ 15mm, micro-spray 15 ~ 20mm, furrow irrigation 20 ~ 30mm. There is no water in the orchard when it rains.

Reasonable amount of fruit to improve fruit quality. The number of ears and grains per ear were determined according to the yield. Early ear thinning and grain thinning will end before fruit softening at the latest, which is beneficial to fruit swelling, fruit surface coloring and sugar accumulation. When the sugar content of fruit is more than 15% and the leaf area index reaches 3, 7m2 can synthesize dry matter about 6 ~ 7kg in sunny day, and the dry matter transferred to fruit is about 4 ~ 4. 5kg. According to the 100th day of fruit development, the theoretical yield does not exceed 2500kg. Excluding the decrease of light utilization efficiency caused by overcast and rainy days, uneven distribution of leaves, poor control of new shoot growth and nutrient waste, diseases and insect pests caused by thinning ears and grains too late, the yield of high-quality vineyard 666.7m2 should be controlled below 1500kg and about 1000kg in high-grade vineyards. The fruiting amount of young trees is calculated according to the total length of new shoots one month after flowering. Taking Jufeng as an example, one ear is suitable for every 2m long new shoots. The amount of fruit retained is related to the total number of branches (effective photosynthetic leaf area), but not to the length of new shoots, ear and grain size, because weaker new shoots can also transport nutrients from other new shoots for fruit expansion and sugar accumulation.

Exuberant branches are peeled around. The overgrowth of branches and vines, the enlargement of fruit grains and the difficulty of coloring will affect the fruit quality. The young trees and overgrown branches can be girdled one month after flowering, and 1 ~ 1. 5cm wide bark can be peeled off with a sharp blade at the base of the vine or on the trunk or main branch, without damaging the cambium, and the peeling mouth is tightly wrapped with plastic film. Because girdling weakens the tree potential, it generally does not circumscribe the trunk, and the yield increases by no more than 20% after girdling.

Branch control. In the period of fruit development, the new shoots should be thinned if the shoots are too dense, and if the branches are too strong, they will pick the heart and control the growth. For example, when the new shoots of Jufeng line stopped growing one month after anthesis, the total length of new shoots per 666.7m2 was controlled at 8000 ~ 10000m, that is, 8000 ~ 10000 shoots with an average length of 1m.