First, the reasons for falling flowers Brass Fitting,Brass Connector,Brass Electrical Fittings Hebei Lanwei Imp. & Exp. Co., Ltd. , https://www.hblanwei.com
What about grape falling flowers and fruit?
1. Variety characteristics. For example, the Kyoho variety has genetically incomplete ovule development, the ovule abnormal rate is as high as 48%, and its filament is rewinded to the back, which is not conducive to pollination. Some varieties are defective in female flower structure, and some are stamen degeneration. The arrangement of pollination trees of female flower varieties is unreasonable, which will cause falling flowers and fruit.
2. The tree is stored in insufficient nutrition. In the early growth stage of the grape, the nutrient storage of the tree is insufficient, which leads to an increase in incomplete flowering period, poor development of the embryonic plant, and low pollen germination rate, resulting in fruit drop. Due to the large amount of flowers, the consumption of water and nutrients is also very large. When trace elements such as potassium, phosphorus and boron are absent in the grape flowering stage, the fertilization ability of the flowers will decrease, resulting in falling flowers and fruits.
3. Improper cultivation and management techniques. The fertilization scheme is unreasonable. Excessive use of nitrogen fertilizer before flowering, excessive irrigation during flowering, improper manipulation of plastic trimming, new shoot restraint, topping, and whole ear are not implemented properly. The contradiction between vegetative growth and reproductive growth during flowering is intensified, leading to falling flowers and fruit. Spraying at the flowering stage will burn the stigma and affect fertilization, leading to fruit drop.
4. Meteorological factors. 1 flowering temperature. The optimum temperature for grape flowering is 20-25 °C. If the temperature before flowering is lower than 10 °C, it will affect the normal differentiation of flower buds. The temperature during flowering period is lower than 14 °C, the flower is poorly developed and falls off; the temperature during flowering exceeds 35 °C, which is easy to cause necrosis of flowers. . 2 flowering rainfall. During the flowering period, the rainy weather makes it difficult to fall off the corolla, and the anthers can not properly loosen the powder. 3 days is insufficient. Continued illuminating before flowering reduced the assimilation of new shoots, and the supply of nutrients in the flowering stage was tight.
5. Physiological fruit drop. When the fruit pieces of the grapes grow to 3-4 mm in size, some of the fruit pieces will fall off due to malnutrition and stop, which is called the physiological fruit drop of the grapes.
Second, preventive measures
1. Choose a good variety. To select resistant grape varieties with better flower development, the female flower varieties should be rationally configured with pollination trees.
2. Supplement the tree nutrition. Most of the nutrient supply of grapes is completed in the early stage of growth. The best period for supplementing nutrients is from harvesting to cold protection. Generally, the harvest of early and middle-aged grapes is applied before harvesting, and the late ripe grapes are applied before harvesting, at the latest in early October. . Human excrement, livestock manure, compost, and manure are mainly used, and 2/3 of the total amount of nitrogen fertilizer is used, and half of the total amount of phosphate fertilizer and potassium fertilizer is used as the base fertilizer.
3. Rational application of nitrogen fertilizer. The internal condition of the tree that causes the fruit to fall is that the water-soluble nitrogen content in the new shoots is high and the carbohydrate content is low, which induces the vigorous growth of the new shoots. Therefore, nitrogen fertilizer should be applied reasonably. Before the flowering (as far as possible), no nitrogen fertilizer should be applied and the base fertilizer should be applied early. Grapes like fertilizer water require more organic fertilizer to enhance the tree potential, but some varieties such as Jufeng are very sensitive to nitrogen. Once there is too much nitrogen fertilizer, especially a large amount of nitrogen is added before flowering, it is easy to cause the shoots to grow, causing the flowers to fall, so flowering No nitrogen fertilizer should be applied before, and the nitrogen fertilizer should be applied after the young fruit is set and harvested in the autumn. The spring top dressing should be applied before the germination. Therefore, topdressing should grasp the three critical periods of pre-emergence, physiological fruit drop, and berry coloring. The first two were mainly nitrogen, phosphorus and potassium, and the third time was mainly phosphorus and potassium. In order to prevent the result from sprouting after germination, the sprouting fertilizer can be avoided under the condition of sufficient base fertilizer.
3-5 days before flowering to the flowering period to control irrigation, the flowering period should avoid drought or flooding water, otherwise it will easily cause falling flowers and fruit. More water should be poured after the flower.
4. Foliar spray of boron. Boron can promote pollen germination and elongation of pollen tube, which is conducive to the completion of pollination and fertilization, and can cause the corolla to fall off normally, thereby increasing the fruit setting rate. In the flower bud stage, the initial flowering stage, and the full flowering stage, a 0.3% boric acid solution is sprayed once, and the effect of adding 0.3% potassium dihydrogen phosphate is better. However, in order to prevent phytotoxicity, the same weight of lime may be added to the boric acid. For severe boron deficiency, mix 1 kg of borax with 25 kg of fine soil before planting the early spring grapes.
5. Scientific pruning. Unreasonable amount of pruning can cause over- or too weak branches, which is also one of the causes of falling flowers. It is necessary to scientifically reduce flowers and thin fruits, reasonably leave branches and retain fruits, and load them reasonably to maintain a stable tree. In line with the principle of "strong branches and light shears, weak branches and heavy shears, moderate strength, support the weak, and maintain the mean", we can effectively prevent falling flowers and fruits.
(1) Wipe. The principle is that the tree is weak and the tree is weak. It should be carried out twice. The sooner the first, the better. It can be carried out after the buds are swollen. The second time is carried out when the leaves are spread. The double buds, small buds, malformed buds and diseased buds are removed, and the round heads are fully budded.
(2) Shuping the tip. The principle is to stay small and stay strong and stay strong. It is carried out twice, the first time when the new shoot length is about 10 cm, and the second time when the new shoot length is about 20 cm. It is also necessary to smear the size according to the size of the frame surface, the main side vines and the resulting mother branches. A new shoot is kept every 10 cm for the cultivation of the hedgerow, and a new shoot of 20/m2 is reserved for the cultivation of the scaffold. The strong main branch of the growth, the result of the branch ring can be more appropriate to leave the result branch; the result of the stout can leave 2-3 result branches for each branch, 1-2 result branches for the moderate, and only 1 result branch for the weak Or cut the inflorescence into a vegetative shoot.
(3) Sparse inflorescence. According to the load and the growth of new shoots, the excess inflorescence is removed in time, and the strong branches can leave two inflorescences. Generally, the fruit branches leave an inflorescence, and the weak branches do not remain. 7-10 days before flowering, cut the tip of the inflorescence by 1/4 or 1/5, and cut the spikelets of the aphid and the shoulder of the ear, leaving 10-12 spikelets in the middle of the inflorescence.
(4) Topping. The topping of the heart should be moderate, and the fruiting rate of the strong fruiting branches is high, and the fruit quality is also good. For the medium fruiting branches, the weak topping is best. 7-10 days before flowering, the new shoots are over-extended, and the weak-developed shoots can be appropriately delayed. 5-6 days before flowering, the result is topping, and it is better to keep 5-7 functional leaves above the inflorescence. At the same time, the tendril should be removed and the secondary tips should be removed. The secondary tips below the inflorescence should be erased. The secondary tip leaves 5-7 leaves to pick the heart, and the other secondary tips leave 1-2 leaves repeatedly. It is advisable to pick the heart to the leaf of 1/3 of the leaf. For the result of strong growth, twisting the top of the inflorescence before flowering can increase the fruit setting rate by about 20%.
(5) The branches are stripped. The ring stripping time is generally 5-6 days before flowering, and the ring stripping site should be selected in the front 3 cm or the first internode of the fruiting branch, and can be carried out with a double-edged stripping knife or a bud-connecting knife. Stripped width 2-3 mm, deep into the xylem, after peeling off the skin, immediately tightly wrapped with a clean plastic film strip. Ring stripping is only suitable for growing strong plants and shoots, and is limited to use on the result branches, and should not be carried out on the main vines.
6. Spray conditioner. This point is mainly used for tetraploid varieties such as giant peaks, which are easy to fall and fall, and diploid varieties are not applicable. Spraying 300 times of B9 or 250-300 times of PBO solution on the foliar surface 10 days before flowering can significantly increase the fruit setting rate.
7. Prevent physiological fruit drop. Physiological fruit drop is a natural fruit thinning for mutual nutrition, which can improve the fruit quality of grapes. However, in order to prevent excessive shedding, the new shoots of the grapes should be controlled in time. At this time, it is necessary to water less, avoid applying nitrogen fertilizer, and apply phosphate fertilizer and potassium fertilizer.
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