1. Zinc deficiency in plants leads to "three generations of old and young", with small leaves, short internodes and low fruit setting rate. Spraying 2,500-3,000 times of American zinc solution 1-2 times with an interval of 10- 15 days before flowering. Because it is difficult for plants to absorb zinc from soil, foliar spraying is more effective.
2. Boron deficiency leads to irregular fruit size. Spraying 1000 times of Bestar gold boron solution or 1000 times of Su Le boron solution 2-3 weeks before flowering.
3. Fruits with severe potassium deficiency are small and irregular, with thin leaves and long internodes. According to the determination, the grape fruit contains 0. 15% nitrogen, 0. 1% phosphorus pentoxide and 0.1%potassium chloride. It can be seen that potassium fertilizer is an important factor affecting fruit quality. Adding potassium fertilizer in the later stage can significantly improve the fruit quality, and spraying 800-fold solution of Baishida No.5 for 2 ~ 3 times can achieve good results.
4. When the hormone containing pyraclostrobin is used as the swelling agent, its concentration exceeds 200mg/kg or the treatment time is too early, which is easy to cause large and small grains. Kyoho varieties should be treated 10 ~ 15 days after flowering.
5. When the tree vigor is too strong, one fruit is easy to form large and small grains, so it should be adjusted in time to stabilize the tree vigor.
There are many reasons for the different sizes of grape fruits in production. The main reason is that the tree is weak, and the nutrients can not meet the needs of fruit expansion when fruit is formed. To prevent the phenomenon of large and small heads of grapes, we must first strengthen the management of fertilizer and water, and appropriately increase the supply of fertilizer and water during the fruit-bearing period of grapes. Generally speaking, we should apply flower-promoting fertilizer before flowering, topdressing after harvest, watering during drought and draining during waterlogging to ensure the robust growth of trees. The second is to prune reasonably. If the amount of flowers is too large, it should be pruned in summer to remove dense branches and weak branches. When the branches are few and the nutrition grows vigorously, the pruning in winter should be appropriately aggravated and thinned, and the flower quantity should be controlled to balance the tree potential. The third is fruit thinning, because grapes set too many fruits, trees consume a lot of nutrients and lose a lot of fruits. Fruit thinning can make the tree load appropriate, maintain the tree vigor, enhance the fruit stamina and overcome the phenomenon of large and small fruits. In addition, proper pollination, pest control, selection of high-quality varieties, application of plant growth hormone and trace elements can improve fruit setting rate, reduce physiological fruit drop and overcome the phenomenon of large and small heads of grapes.
Lack of nutrient elements boron and zinc will lead to the phenomenon of large and small fruits in grapes. The soil in southern China is generally short of boron, so the vineyard should be fully applied with boron fertilizer. 2 ~ 3 kg borax per mu when applying germination accelerating fertilizer; Spraying 0.2% borax solution10 ~ 2 weeks before flowering; When the pulp turns brown after fruit setting and the fruit surface is sunken, 0.2% borax solution should be sprayed. Su Le boron and long-acting boron are efficient and quick-acting boron fertilizers, so topdressing outside the roots should be selected. For vineyards lacking zinc, 0.2% ~ 0.4% zinc sulfate and equivalent lime can be sprayed 2 ~ 3 weeks before flowering.
The above information is for reference only. You are welcome to consult again.
In recent years, the phenomenon of large and small grains in Kyoho grape production is very prominent, especially for trees over 4-5 years old, which has become a long-standing problem in grape production. According to the investigation and analysis, the phenomenon of "Kyoho" grape producing large and small grains is mainly caused by the vigorous tree vigor, and there are many reasons for the vigorous tree vigor. Some grapes produce large and small grains on the whole plant, while others are on a certain part or branch. Therefore, according to the characteristics of different vineyards, we must find out the reasons and strengthen management, which will certainly receive better results.
First, the main reasons for the phenomenon of grape size:
1, fertilizer and water management is out of control, too much nitrogen fertilizer is applied, and the water supply is too large.
2. The plant load is light, the corresponding yield can not be reached, and the branches are white and long.
3. Unreasonable pruning and uneven tree potential.
4. Only apply chemical fertilizer, ignoring the application of organic fertilizer.
5. At flowering stage, the period of picking the heart and breaking the vine is early, leaving fewer leaves.
6. The amount of topdressing before flowering is unreasonable.
7. During flowering period, dense shelves, many branches and poor ventilation and light transmission lead to flowering abortion, low fruit setting rate and loose ear.
8. The single and double vines of the plant are too short and the shelf surface is too low, which leads to the vigorous growth of the plant, especially the grafted seedlings.
Second, measures to control the phenomenon of large and small particles:
1. water control: before flowering, the soil below the surface 10 cm can be agglomerated with one hand. Generally, it can be watered twice before flowering, and low-lying land or clay can be watered 1 time or not.
2. Fertilizer control: no nitrogen fertilizer is applied before flowering, and little or no organic fertilizer is applied. After fruit setting, the water content should be increased when the seeds grow to the size of soybeans, and more phosphorus and potassium fertilizers should be applied from the hard core stage to the coloring stage.
3. Reasonable adjustment of plant load: it is appropriate to keep the grape trees over 4 years old at about 65,438+00 kg. When the flowering period is less than 20 cm, there will be no fruit left. When the thickness is more than 20 cm and 65,438+0 cm, binaural fruit or binaural fruit will be left, especially for the strong branches at the corners and the top of the stand.
4. Reasonable pruning: In this way, strong branches with a branch spacing of less than 25 cm (referring to branches with a thickness greater than 1.2 cm) will be thinned out. In this way, if the branch spacing is more than 20 cm, it is necessary to take multi-bud pruning to fill the vacancy, but when fixing branches in the next spring, leave two ends in the middle and master the branch spacing. If the branch spacing is about 25 cm, three buds can be left, and the top bud can be erased when the bud is applied in the next spring, and 1 ~ 2 buds can be left to bear fruit, and strong branches can be left with two ears. The result is that if the branch distance 15 ~ 20 cm is long, leave the basal buds to bear fruit, erase the rest and keep the tree in a moderate state.
5. Pick the tip and break the vine: It is not appropriate to pick the tip and break the vine too early, and it is appropriate to take 3-5 days before flowering. In the double-bud fruiting branch group, the tip should be kept long, with 6-8 short branches and 8- 10 long branches, with no or less coring when the ear length is below 10 cm, and about 60 cm.
6. Cut off the surface roots: All Kyoho grape trees over 4 years old need to cut off the surface roots if they produce large or small grains. The method is to cut off the surface roots with a shovel after autumn and before taking off the shelves, and the distance from the root cutting to the plant base should not exceed 10 cm, otherwise the effect will not be achieved. After root cutting, the growth is slightly slower in spring and the leaves are yellow. After fruit setting, it is necessary to strengthen fertilizer and water management and quickly restore tree vigor.
7. Twisting branches: Twisting branches at the upper part of the ear, bending or flattening them 3-4 days before flowering.
8. Using secondary branches: When grape grains are almost as big as soybean grains, the phenomenon of large and small grains is already obvious. The above branches and leaves can be cut off at the time of 5 ~ 6 leaves, and it is suitable to bear fruit with secondary branches before June 20, with high fruit-setting rate and neat ear, but the maturity is after 7 ~ 10 days.
9. Use swelling agent: When the size and grain size of Kyoho grape have been clearly seen (about 15 days after flowering), soak the ear 1 time (or spray the fruit evenly). During the period from fruit bouncing to coloring, if fruit cracking is found, water should be controlled in time or drained after rain.
10, using a new fruit tree promoter-PBO: it has the characteristics of promoting grape grain size, positive color, early maturity, crack prevention and yield increase, and the dosage depends on the tree condition. For the first time, soil 1 ~ 2 was applied two days before flowering, and Wangshu was suitable for watering, with 5 ~ 7 grams per plant; Each tree is 2.5-3g, with about 250g of scaffolding and 250-500g of hedges. The second spraying is about 25 days after flowering, and the concentration of liquid medicine is 100 ~ 250 times. Practice has proved that the use of PBO in fruit setting of Jufeng Wang Shu has increased obviously, and it is not necessary to control nitrogen fertilizer. Urea should be applied in the first half of April, and each plant should be100 ~150g. After germination, it should be sprayed together. After mid-June, potash fertilizer is the main fertilizer, and foliar fertilizer cannot be interrupted. Immediately after harvest, apply postpartum fertilizer twice and irrigate. From the end of September to the beginning of 10, more than 3000 kilograms of farm manure was applied and watered twice.
It should be noted that the after-effect period of PBO applied in soil is 1 year, which should be carried out every other year and sprayed in the second year. The effect of using PBO to increase production is obvious, so we should pay attention to controlling production.