How to control the size of grapes? How are they formed?

Jufeng, Jingya, Golden Finger and other varieties have all experienced the phenomenon of grape size and grain size, among which Jufeng grape is the most serious, with an incidence rate of more than 80%.

(1) Grape size: Grape size refers to the phenomenon that some grapes are smaller than normal, and the difference is large, and the fruit size is uneven. It began to appear obviously at the stage of young fruit expansion. At this time, the normal fruit grains expand rapidly, while the small grains are smaller in size and more round in shape than the normal ones. Cut the fruit, there are no seeds in the small grapes, there are few seeds, or the seeds are not well developed. During the coloring period, small particles can not be colored normally, which seriously affects the yield, quality and product price of grapes.

(2) Cause analysis: The root cause of the phenomenon of grape size and grain size is the abnormal development of grape floral organs and the process of pollination and fertilization, which leads to the abnormal pollination and parthenocarpy of grapes. The main factors leading to grain size are: variety characteristics, lack of trace elements such as boron, improper management of water and fertilizer, unfavorable weather factors, vine potential and so on. In production, many factors often work together.

(3) Preventive measures: For grape-sized particles, fruit expansion can be used. When the young fruit grows to the size of soybean, soak or spray the ear with 0. 1% chlorfenuron (KT-30) 100~ 150 times solution to eliminate grape grains. Clopidogrel is a growth hormone regulator. The efficacy of growth hormone regulators is limited by many factors. Because of different management and cultivation conditions, different application time and weather conditions at that time, different application concentration and grape growth, it is difficult for fruit farmers to master the application time and concentration. After applying pesticides, the quality of grapes often declines; The fruit stalk is hard and easy to fall off, so it can't be transported for a long distance. Peel thinning, easy to crack fruit; Fruit expansion can only be used as a remedial measure (except seedless varieties such as Xiahei, which need to lengthen the ear and enlarge the grain), and the fundamental solution is to prevent the occurrence of large and small grains through some scientific cultivation and management measures.

Specific measures are as follows:

Variety upgrade: Jufeng series varieties are obviously large and small. Therefore, it is necessary to adjust measures to local conditions and improve or update varieties on the basis of experimental demonstration.

Reasonable Load, Scientific production quotas: Standardize production, strictly formulate production quotas, and ensure stable production. Generally, an orchard yields about 4000 Jin per mu, with a maximum of 5000 Jin. Prune the ear in time after flowering, remove excessive ear, pinch off the secondary ear and ear tip.

Control vigorous growth and adjust nutrient distribution: 1. Results Five leaves were left above the branches, and then the core was taken, and two leaves were left in the new pair, and then the core was taken repeatedly. Control the excessive nutrient consumption of branches, so that the ear can be distributed with sufficient nutrients. 2. Control fertilizer and water before flowering. Do not apply nitrogen fertilizer before flowering, and water according to soil moisture. The soil below the ground 10 cm should be caked with one hand. Because of fruit setting, when soybean seeds grow to large size, they need big fertilizer and water, and more phosphorus and potassium fertilizers should be applied from hard core stage to coloring stage.

Improve the resistance to adverse weather: In the germination stage, 5 days before and 5 days after flowering, * * * spraying 5,000 times of Bihu (red Inb Brassica) for 3 times can significantly improve the resistance of plants.

Spraying micro-fertilizer on leaves and increasing organic fertilizer to improve soil physical and chemical properties: 1. Spraying 0. 1%~0.3% borax solution and 0. 1%~0.3% zinc sulfate solution twice before and after flowering. It can quickly supplement boron and zinc, prevent poor flowering, pollination and fertilization, and thus prevent the occurrence of flower drop, fruit drop and grain drop. 2. Applying more organic fertilizer and improving soil physical and chemical properties are important measures to overcome the lack of trace elements in grapes. When organic fertilizer is applied to soil, the mineralization of organic matter can release some boron, which will be beneficial to the absorption and utilization of plants. Therefore, the application of organic fertilizer can increase the boron content in soil and meet the demand of plants for boron. In the production process, according to the principle of soil testing and formula fertilization, the application amount of nitrogen fertilizer is reduced and the application amount of organic fertilizer is increased.

After the fruit is picked in autumn, a fertilizing ditch with a width of 40cm and a depth of 40cm is excavated along the main vine 60cm away from the grape row, and 4000-6000kg of decomposed organic fertilizer and excavated soil are infiltrated into the ditch per mu. Applying soil without fertilizer infiltration at the distance of 0/5 cm from the surface/kloc-can induce the root system to grow deeper, improve the tree potential and reduce the probability of large and small seeds.

Circumcising and controlling prosperity: Kyoho grape is a tetraploid variety in Europe and America, which has a strong innate genetic advantage. However, in the environment of yanshi city, under the conditions of good water, soil and fertilizer, the tree tends to be vigorous, and the phenomenon of size and grain is obvious. By girdling, the area coefficient of the front leaf of the bearing branch of Kyoho grape can be improved, so as to increase the storage of carbohydrates, balance the ratio of carbon to nitrogen, promote the maturity of branches and flower bud differentiation, increase the cellulose of trees, harden the wood and stabilize the growth of trees. After girdling, the tree vigor is relatively weakened, and the internodes of flower buds are shortened, which overcomes the contradiction between vegetative growth and reproductive growth, thus ensuring a better fruit setting rate. Ring cutting should be strictly controlled 7 days before flowering, the width of ring cutting for over-prosperous grapes is about 5 mm, and that for middle-prosperous grapes is 3 ~ 4 mm.