What Causes Grape Fruit Drop
Today's small experience sharing: An introduction to the green plants and flowers on why grape fruit drop occurs, next, the editor will introduce to the netizens.
What Causes Grape Fruit Drop
The reasons for grape fruit drop may include issues with the grape variety itself, lack of nutrition leading to shedding, which is normal, or due to diseases and pests, as well as natural weather conditions. To address the issue of grape fruit drop, the preventive methods include selecting good varieties, supplementing tree nutrition, and applying nitrogen fertilizer appropriately, which have relatively good effects.
Reasons for Grape Fruit Drop
1. Physiological fruit drop: When the fruit is about three to four millimeters in size, some may drop due to lack of nutrition, which is normal. 2. Sunscald fruit drop: During the hardening and coloring stage of grape fruit, high temperatures can cause some fruits to dry and turn black under strong sunlight. This is due to excessive nitrogen fertilizer applied in the early stage leading to large leaves. 3. Disease-induced fruit drop: Grapes are prone to diseases during the rainy season with high temperature and humidity, such as downy mildew, powdery mildew, black spot disease, and (T-J) disease, which can lead to fruit drop. 4. Pest-induced fruit drop: Pests like red spiders can also cause grape fruit drop. Variety characteristics: Some grape varieties have inherent genetic defects, such as Kyoho grapes inheriting the trait of easy flower and fruit drop from their parents. Unfavorable growing climate: Adverse external conditions and abnormal climatic conditions, such as drought, high temperatures, low temperatures, continuous rainy weather during the flowering and young fruit stages, can cause a large number of flowers and fruits to drop. Improper management measures: Improper agronomic measures can lead to insufficient internal nutrition, improper nutrient distribution, or imbalance between vegetative growth and reproductive growth, as well as excessive application of nitrogen fertilizer and dense pruning. Boron deficiency: Soil boron deficiency or insufficient boron absorption can lead to boron deficiency in grapevines. Boron deficiency can cause poor pollination, and the poorly pollinated berries are at a disadvantage when competing for nutrients with healthy berries, leading to flower and fruit drop. Diseases and pests: Green盲蝽, thrips, mites, and diseases like downy mildew, gray mold, and axis brown rot can cause flower and fruit drop. Improper use of hormones: Some hormones have a flowering-thinning effect and should be used with caution. Improper dosage or timing can cause severe flower and fruit drop.Reasons for Grape Fruit Drop During Maturation
1. Imbalance of tree nutrients: Mainly due to the imbalance between the growth of the vine and the fruiting growth, excessive tree growth can lead to insufficient nutrition for the development of the berries, causing a large number of fruit drops. In addition, boron deficiency and ovule development can also cause fruit drop. 2. Improper management: Fruit drop may be caused by improper use of fertilizers, excessive application of nitrogen fertilizer, causing excessive tree growth, and occurrence of luxuriant growth. Excessive fruit retention and excessive tree load can cause insufficient nutrition for berry development, leading to fruit drop. Improper pruning and vine management can also cause uncontrolled tree growth, as well as improper water management. 3. Climatic reasons: Low temperature, high temperature and drought, rainfall, insufficient sunlight, and strong wind can cause a large number of fruit drops. 4. Reasons related to diseases and pests: Severe occurrences of diseases like gray mold and downy mildew, and pests like red spiders and leafhoppers can lead to a large number of grape fruit drops.What to Do When Grape Fruit Drop Is Severe
Grape fruit drop may occur due to excessive sunlight exposure during growth, causing the vines to be scorched and drop. Appropriate shading is needed for the plants to grow healthily. It may also occur due to improper watering methods, leading to fruit rot and drop. Proper water supply is necessary for the plants.What Medication Is Good for Grape Fruit Drop
During the bud stage, early flowering stage, and full flowering stage, spray 0.3% boric acid solution once each time. Adding 0.3% potassium dihydrogen phosphate spray can achieve better results. However, to prevent phytotoxicity, the same amount of lime can be added to boric acid.What Medication to Use to Increase Grape Fruit Setting
In the early fruit stage, pay attention to the prevention and control of powdery mildew, gray mold, axis brown rot, and thrips. For gray mold treatment, preventive protection can be done with thiram and validamycin. Treatment can be done with pyrimethanil, propamycin, fludioxonil, polyoxin, carbendazim, and trichoderma, among others, alternating for control.Methods to Prevent and Control Grape Fruit Drop
1. Select good varieties: Choose grape varieties with well-developed flower organs and disease resistance, and rationally allocate pollination trees for female flower varieties. 2. Supplement tree nutrition: Most of the nutrient supply for grapes is completed in the early growth stage. Use organic or farmyard manure as the base fertilizer, with 2/3 of the total nitrogen fertilizer and half of the phosphorus and potassium fertilizers applied together. 3. Apply nitrogen fertilizer appropriately: Nitrogen fertilizer should be applied appropriately, avoiding application before flowering and applying base fertilizer early. Grapes prefer fertilizers and water, requiring more organic fertilizers to enhance tree vigor. 4. Spray boron on leaves: Boron can promote pollen germination and pollen tube elongation, facilitating pollination and fertilization, and enabling normal corolla shedding, thus increasing fruit setting rate. For severe boron deficiency, 1 kilogram of borax mixed with 25 kilograms of fine soil can be applied around the plant before the early spring grape germination. 5. Scientific pruning: Improper pruning can cause excessive or weak vine growth, which is also a reason for flower and fruit drop. It is necessary to scientifically thin flowers and fruits, reasonably retain branches and fruits, and maintain a stable tree vigor.Have you understood the detailed introduction to the causes of grape fruit drop shared above?