Etiology: Due to the influence of adverse environmental and climatic conditions before and after flowering, the buds can not be fertilized normally, resulting in a large number of flowers and fruits falling. For example, the drought temperature at flowering period is higher than 32℃; When flowering, there is no insect or wind, and pollination is poor; At flowering stage, the soil moisture content is high, and the vigorous growth of new shoots causes nutrient competition; Do not shoot new shoots before flowering, and the nutrition grows vigorously; Boron deficiency in soil affects pollen germination and pollen tube growth, resulting in poor fertilization; The temperature at night is lower than 65438 05℃, which affects pollination and fertilization; Too many branches and the deterioration of light conditions will induce serious grape blossom and fruit drop.
Prevention and control methods:
① Pay attention to irrigation about half a month before flowering, spray 0.3% borax +0.7% brown sugar +600 times "Tianda 2 1 16" on the leaves, and control irrigation at flowering stage.
(2) After the ear is elongated, pick the accessory ear and pinch off the ear tip in time, and pick the new tip 2-3 days before flowering to control the vegetative growth, promote the reproductive growth and improve the fruit setting rate.
(3) Adjust the temperature of the facility during the flowering period, and maintain it at 25-30℃ during the day and 15- 18℃ at night. Provide favorable environmental conditions for grape pollination and fertilization. So as to improve the fruit setting rate.
(4) When flowering, cut a fan between the grapes to promote pollination and improve the fruit setting rate.
Question 2: What are the reasons for the falling flowers and fruits of grapes? There are many reasons for grape flowering and fruit dropping, such as biased application of nitrogen fertilizer, excessive growth, bad weather during flowering, lack of phosphorus and boron, improper use of regulators and so on. Therefore, the protection of grape flowers and fruits also needs all-round management. In addition to nitrogen control, coring, shaping and pruning ears, spraying regulators and other measures, attention should also be paid to supplementing phosphorus, zinc and boron. Four or five leaves in the whole garden began to supplement key nutrients through foliar spraying. Spraying micro-fruit-supplementing force+boron force two or three times before flowering can strengthen the ear, promote flowering, promote pollination and fertilization, and spray it twice after flowering to reduce the lack of elements and fruit drop.
Question 3: What causes the grapes to fall out of flower and fruit? This may be caused by element deficiency. We can make money from medium and micro-fertilizer seedlings, supplement trace elements such as zinc, silicon, molybdenum and copper needed for grape growth, and promote the growth of roots, stems and leaves.
Question 4: What happens when grapes fall after flowering? Falling flowers and fruits refer to physiological falling flowers and fruits caused by internal reasons of trees, excluding falling flowers and fruits caused by pests and diseases and strong winds. Like other fruit trees, falling flowers and fruits of grapes is a physiological disorder in the body. If it is light, it does not affect the yield, which belongs to normal flower drop and fruit drop; If it is heavy, the fruit setting rate is very low, resulting in a large area of production reduction, which can be described as abnormal flower drop and fruit drop. After the grapes wither, there is a physiological phenomenon of falling flowers and fruits. The peak of flower drop is within 1 week after flowering, and then it will drop sporadically and gradually stabilize. There are both internal and external causes of grape falling flowers and fruits. The internal reasons mainly include unbalanced tree nutrition, incomplete flower development, too high nitrogen content, unreasonable pruning, boron deficiency, incomplete ovule development, incomplete flowering development and incomplete pollination and fertilization process. External causes include low temperature, rainfall, insufficient sunshine, high temperature and drought, excessive nitrogen fertilizer, chemical substances leading to stigma infertility, bacterial infection and so on.
Second, preventive measures
1, intensive cultivation measures
The first is to choose good varieties. Grape fruit is related to the variety sooner or later. Generally, European and American populations are easy to form flower buds, with high fruit setting rate and easy to obtain early high yield. Such as Kangtai, red banana, red dense, white banana and so on. The second is to cultivate strong seedlings. Strong seedlings not only have high survival rate, but also recover and grow quickly in the same year of planting, forming vigorous aboveground parts and roots. In recent years, people have taken measures to promote rooting, such as hormones, sunshine temperature, brewing heat, fire resistance or electric bed to cultivate strong seedlings. The third is scientific fertilization. Choose a suitable place and soil to build a garden, open a big ditch in the garden, apply sufficient base fertilizer, and improve the soil every year at a young age. Organic fertilizer should be no less than 75~ 150t/hm2, and appropriate amount of calcium superphosphate or calcium magnesium phosphate fertilizer should be added, and compound fertilizer should be applied for many times during the growth period, so that the root system of the grape can be developed, the vegetative growth and reproductive growth of the upper part can be promoted, and a large number of flower buds can be formed in the early stage, and normal flowering and fruiting can be achieved. The fourth is reasonable close planting. Only by carrying out planned close planting and giving full play to group advantages can we make full use of land and light energy in the early stage, quickly occupy the shelf surface, improve coverage and leaf area index, and obtain early high yield.
2. Improve the nutritional status of trees.
Grape growth and flower bud differentiation are based on nutrition, so strengthening management, improving the tree body and improving and enriching the nutritional level of the tree body are the fundamental measures to protect flowers and fruits. First, soil improvement and fertilization. Continuously supply all kinds of nutrients needed by trees, and gradually implement the formula fertilization system with organic fertilizer as the main body to control fruit yield. Too many fruits are left, and the proportion of leaves and fruits is out of balance, which will lead to fruit drop. By thinning the fruit, the reasonable leaf-fruit ratio (20∶ 1) was maintained, so that there were enough leaves to make nutrients for flower bud differentiation. The second is to protect the leaves. Leaves are the main organs that produce and absorb nutrients. Strengthen the management of leaf protection, avoid premature defoliation, prolong the life of leaves and improve the photosynthetic capacity of leaves. The third is to increase the application of trace elements. Lack of trace elements, especially boron, can also lead to flowering and fruiting. When boron is deficient, the pollen germination rate is low, and the corolla is still not open when flowering, and it clings to the ovary, and then turns brown and dies. When boron fertilizer is used as base fertilizer, 1kg borax is mixed with 25kg fine soil and applied around the plants before the grapes germinate in early spring, or 0.3% borax solution is sprayed on the leaves, and 1 time is sprayed in bud stage, early flowering stage and full flowering stage respectively. GwyOO.cOm target = _ blank & gt； GwyOO.cOm
3, mediation tree nutrition
It is mainly to mediate the contradiction between growth and fruiting for nutrients, so that the nutrients in the body can meet the needs of each period in time, and the growth, flowering, fruiting and flower bud differentiation can develop in a coordinated and balanced way. The first is to pick the heart. It can temporarily prevent new shoots from competing with inflorescences for nutrients, increase the nutrients supplied to tidbits, and achieve the purpose of protecting flowers and fruits. The greater the intensity of pit removal, the higher the fruit setting rate, and the lighter the pit removal, the worse the effect, so the pit removal should be moderate. For the branches with coarse fruit, the strong stone removal treatment has high fruit setting rate and good fruit quality, followed by medium stone removal and weak stone removal. For middle-bearing branches, weak coring treatment is the best, and middle coring treatment is the best ...
Question 5: What is the reason why grapes don't bear fruit when they fall? Grape fruit drop is the disease of grape fruit drop.
The shedding of flower buds and ovaries within L weeks before and after the flowering of grapes is called falling flowers and fruits, and the rate of falling flowers and fruits is above 80%, which is called falling flowers and fruits disease.
Occurrence law
It is mainly because the change of external environmental conditions has affected fertilization and pollination, resulting in a large number of flowers and fruits falling off. If the flowering period is dry or rainy, or it is windy or encounters low temperature, it can cause poor fertilization and a large number of flowers and fruits fall; Too much nitrogen fertilizer is applied, and the new shoots grow in vain at flowering stage, and vegetative growth and reproductive growth compete for nutrients, resulting in insufficient nutrition in the development of panicles, which leads to falling flowers and fruits; The branches are too dense and the ventilation and light transmission conditions are poor; Boron deficiency in plant growth will limit the germination of pollen and the normal growth of pollen tubes, and also seriously affect the fruit setting rate.
Prevention and cure method
(1) For varieties with serious flower and fruit drop, such as Rose Fragrant and Kyoho, seeds can be picked 3-5 days before flowering to control vegetative growth and promote reproductive growth. (2) For varieties with excessive growth potential, we should pay attention to light cutting and long release, weaken vegetative growth and alleviate tree potential. ③ Before and after flowering, it is necessary to apply topdressing and irrigation, apply more phosphorus and potassium fertilizer, and control the application of nitrogen fertilizer. ④ Spraying growth regulators such as B9 or chlormequat before flowering can inhibit vegetative growth and improve the nutritional status at flowering stage. ⑤ Spraying 0.05 ~ 0. 1% borax before flowering can improve the fruit setting rate. You can also sprinkle borax 30 ~ 50 cm away from the trunk and then water it, which can get good control effect.
Question 6: What is the reason why Xiahei series grapes fall when they bloom in greenhouse? Please check 19 1 and go to Nongrenren.com to ask everyone. More than130,000 registered members.
Question 7: What's the matter with the serious falling flowers and fruits of the planted grapes? There are many reasons why grapes fall, such as improper management in grape production or the weather, so it is hard to say.
Question 8: How about Kyoho Grape? Jufeng grape is a variety with serious flowers and is conducive to flowering. Static fruit essence and boron fertilizer at flowering stage can protect flowers and promote pollination, and spraying clofenuron a few days after fruit setting can protect fruits.
Question 9: What are the reasons for poor germination and differentiation of grapes, serious flowering and fruit dropping, and small panicle and small fruit? The growth of vines is very weak, and they should not be allowed to bear fruit without storing enough nutrients. The main purpose is to promote the growth of nutrients, such as the healthy growth of vines. It is necessary to sparse flowers and trim (cut) fruits.
Question 10: What's the matter with grape bud dropping during flowering? A week before and after the flowering of grapes, the flower buds and ovaries fall off, which is called flower drop and fruit drop disease, and the rate of flower drop and fruit drop is above 80%. It is mainly because the change of external environmental conditions has affected fertilization and pollination, resulting in a large number of flowers and fruits falling off. If the flowering period is dry or rainy, or it is windy or encounters low temperature, it can cause poor fertilization and a large number of flowers and fruits fall; Too much nitrogen fertilizer is applied, and the new shoots grow in vain at flowering stage, and vegetative growth and reproductive growth compete for nutrients, resulting in insufficient nutrition in the development of panicles, which leads to falling flowers and fruits; The branches are too dense and the ventilation and light transmission conditions are poor; Boron deficiency in plant growth will limit the germination of pollen and the normal growth of pollen tubes, and also seriously affect the fruit setting rate.
Precautions can be taken before flowering. 1, you can pick the heart 3 ~ 5 days before flowering, control vegetative growth and promote reproductive growth. 2. For varieties with excessive growth potential, we should pay attention to light cutting and long release, weaken vegetative growth and slow down tree growth. 3. Before and after flowering, we must apply topdressing and irrigation, apply more phosphorus and potassium fertilizer, and control the application of nitrogen fertilizer. 4. Spraying growth regulators such as B9 or chlormequat before flowering can inhibit vegetative growth and improve the nutritional status at flowering stage. 5. Spraying 0.05 ~ 0. 1% borax before flowering can improve the fruit setting rate. You can also sprinkle borax 30 ~ 50 cm away from the trunk and then water it, which can get good control effect.