Why are grapes bagged? When is bagging appropriate?

In order to prevent the grapes from growing insects, they should be bagged at the beginning of fruiting, but they need to be allowed to grow later.

Grape bagging is done to prevent diseases and pests, but also to prevent the grapes from being burned by the heat. Generally, when the fruit set is relatively stable, the bag is selected in the right weather.

The purpose of bagging is to avoid too much light, and bagging is best done in May.

Grape bagging is generally carried out as early as possible after the first fruit thinning of the fruit ears, and avoid the high temperature weather after the rain, and the bagging time should not be too late. However, in areas where the sunburn is more severe in the northern part of the country, bagging can be postponed appropriately. Before bagging, the whole park should be sprayed with fungicides, such as carbendazim and other pesticides, and then bagged.

In order to prevent sunburn, leave ventilation holes in the lower corners of the fruit bag. Red grape varieties need to be bagged 10 to 20 days before the grape harvest to add color. For easily colored and colorless varieties, as well as in the Northwest where the coloring is too heavy, it is possible to leave the bag unpicked and bag until harvesting.

In order to avoid the damage of various undesirable factors during the ripening period to the grapes, do not remove the paper bag at one time when picking the bag, you can open the bottom of the bag first, and then gradually remove the fruit bag.

Grape bagging should be based on the variety and the climatic conditions of each region, and choose the appropriate types of fruit bags.

Bagging period: Grape bagging period generally starts immediately after the fruit setting is stable, the whole ear and thinning are finished, and ends before the rainy season comes, in order to prevent early infection and prevent sunburn, to avoid the high temperature weather after the rain or the sudden sunny weather after the rain is carried out bagging is carried out, generally after 2-3 days, and then bagging after the fruit is slightly adapted to the high temperature environment.

Bagging method: before bagging, the orchard should be fully sprayed with fungicide, focusing on spraying the fruit ear, and then bagging after the liquid is slightly dry, first immerse the bag mouth end 6-7cm in water to make it moist and soft, easy to shrink the bag mouth, when bagging, first use your hand to stretch the paper bag open, so that the paper bag bulges, and then from the bottom to the top of the entire fruit ear into the bag, and then shrink the bag mouth to the ear handle, with one side of the sealing wire to tie tightly, above the wire to be left with the paper bag, it is strictly forbidden to rub the fruit ear with hand when bagging.

Grape bagging prevents and mitigates fruit diseases.

The bagging grape fruit is isolated from the outside world by the fruit bag, and the physical method is used to block the channel for the spread of germs from other objects to the fruit ear and fruit, reduce the chance of disease and insect infection on the fruit, and effectively prevent the occurrence of black pox, anthracnose, white rot, downy mildew and other occurrences on the grape fruit.

Grape bagging can reduce the amount of pesticides used and reduce pesticide residues. After bagging, various pesticides cannot be sprayed on the fruit. In particular, if the agent used after bagging is not systemic and the sprayed pesticide will not affect the fruit; In the case of systemic agents, the dose of the agent transmitted to the fruit is also greatly reduced.

Therefore, grape bagging will reduce the pesticide residue in the fruit, which is an important measure to produce safe food and increase the trust of agricultural products, which has far-reaching significance. Practice has proved that during the grape growing season, the disease prevention link of bagging viticulture can reduce the use of drugs 4-5 times.

Different varieties have different disease resistance, and Eurasian species are less resistant to disease and should be set early, such as red earth, beauty finger, etc.; European and American hybrids are more resistant to the disease, but they can be later, such as Jufeng, Tota 8, etc.; Purpose of bagging: For the purpose of disease prevention, after thinning the fruit, bagging as soon as possible, should be sooner rather than later; In order to improve the appearance of the fruit, the grapes are bagged before they are colored. When the temperature is high, it is not suitable for bagging at 11-14 o'clock at noon, spraying before bagging, and then bagging when the fruit surface is dry.

Grape bagging can significantly improve the quality of fruits, protect fruits from pests and diseases, reduce pesticide residues, improve fruit appearance, improve fruit grades, increase economic income, and enhance market competitiveness, which is an effective measure for the production of high-quality and pollution-free grapes. 1. Types of fruit bags: Grape bags should be selected according to the varieties and different climatic conditions of each region.

2. Bagging period: The grape bagging period generally starts immediately after the fruit setting is stable, the whole ear and the end of the grain thinning season, in order to prevent early infection and prevent sunburn, to avoid the high temperature weather after the rain or the sudden sunny weather after the rain is carried out, generally after 2-3 days, and then bagging after the fruit is slightly adapted to the high temperature environment. 3. Bagging method:

Before bagging, the orchard should be fully sprayed with fungicide, focusing on spraying the fruit ear, and then bagging after the liquid is slightly dry, first immerse the bag mouth end 6-7cm in water to make it moist and soft, easy to shrink the bag mouth, when bagging, first use your hand to stretch the paper bag open, so that the paper bag bulges, and then from the bottom to the top of the entire ear into the bag, and then shrink the bag mouth to the ear handle, with one side of the sealing wire to tie tightly, in the wire above the paper bag to be left, it is strictly forbidden to rub the ear with hand when bagging.

4. Management after bagging: After bagging, you can no longer spray pesticides for fruit diseases and pests, focusing on the prevention and control of grape leaf pests and diseases such as leafhoppers, downy mildew, etc., and the pests such as corn elephants, Kang's mealybugs, tea yellow thrips and other pests that are easy to enter the bag should be closely observed, and the pests can be sprayed when the damage is serious, and the agent can be used 2000-3000 times 30% of the poisonous emulsifiable concentrate, 1200-1500 times 48% of Lesben, etc. 5. Time and method of bagging:

After the grapes are bagged, they can be harvested with bags, or they can be bagged about 10 days before harvesting, and the red quality can be bagged about 10 days before harvest to increase the light reception of the fruit and promote good fruit coloring. When the grapes are bagged, do not remove the bag at one time, the bottom of the bag should be opened first, so that the fruit bag is put on the upper part of the fruit spike, in order to prevent bird damage and sunburn, the bag time should be carried out before 10 am or 4 pm on a sunny day, and it can be carried out all day on a cloudy day. 6. Management after bag removal:

Grape after the bag generally do not need to spray, but must closely observe the progress of fruit coloring, after the bag can be cut off near the ear of some of the aging leaves and overly dense branches on the shelf, in order to improve the ventilation and light transmission conditions of the shelf, reduce the harm of pests and diseases, and promote the coloring of the fruit, but it is necessary to pay attention to the leaf picking can not be too much, too early, it is worth pointing out that the leaf picking should not be carried out at the same time as the bag, but should be carried out in phases and batches to prevent sunburn.

Grape bagging is to pay attention to those things! Do you know these basic methods? Very useful.

Grape bagging is to pay attention to those things! Do you know these basic methods? Very useful.

The grapes are bagged after the second fruit thinning, when the fruit powder can basically be seen, not too early, not too late. If it is too early, it will not absorb enough sunlight, which will easily lead to small fruits. Too late, the grapes are susceptible to diseases and pests, resulting in a decrease in fruit quality and yield.

In addition, when bagging, it is necessary to avoid the high temperature weather after the rain and the sudden sunny day after continuous rain, try to choose the normal weather before 10 o'clock in the morning, when the sun is not strong in the afternoon, and end before the rainy season, which can reduce the occurrence of sunburn.

Bagging precautions.

When bagging, the bag is propped up, the air vents at the bottom of the bag are opened, and then the bottom of the bag is held by hand and the bag is bagged from top to bottom. After all the fruits are packed, the branches are tied tightly with wires.

The fruit must be in the ** area of the fruit bag, together with the fruit stalk, and tied tightly with iron wire at the fruit branch. Excessive force will damage the fruit and fruit stalk. The fruit stalk is tied in the bag to facilitate growth, which can prevent pests and diseases from eroding the fruit grains along the fruit stalk.

Grape bagging can be carried out after the plant sets fruit, and the fruit ears need to be wrapped in a waterproof paper bag during the bagging, and then fixed with iron wire, and at the same time, it is necessary to provide mineral-rich water and fertilizer for the grapes after bagging to maintain the normal growth of the plant, and can also provide sufficient light for the grapes, so that the plants can produce better quality fruits.

1. Bagging time

Grape bagging can be done after fruit set, i.e. in July and August. And before bagging, you need to cut off the secondary spikes on the spike to help the plant save nutrients, and at the same time, you need to use your hand to stretch the paper bag when bagging, and then put it on the spike, use the wire to tie the paper bag tightly and fix it on the vine.

2. Provide moisture

Grapes are suitable for growing in a more humid environment, so it is necessary to provide sufficient water for the plants when maintaining grapes in the later stage, and it is best to provide grapes with natural water or lake water with rich mineral content, and when watering, you need to pour water directly into the soil to soak all the soil.

3. Suitable for light

Grapes are inseparable from light in the process of growth, and insufficient light will cause the leaves of grapes to turn yellow, or the fruit is not long, so it is also necessary to provide sufficient light for the plants when maintaining grapes, so that the grapes can photosynthesize normally, and when the light is too strong, it is necessary to shade the plants in time to let the grapes grow healthily.

4. Reasonable nutrients

Grapes are suitable for growing in a more fertile environment, so when maintaining grapes, they can also provide sufficient nutrients for the plants, and it is best to provide them with nitrogen fertilizer or rotting organic fertilizer during the grape growing period to improve the growth rate of the plants, and provide phosphorus and potassium fertilizer for the grapes when they bloom and bear fruit, so that the plants can produce more fruits.

The grapes grow to the size of a bean and can be bagged about 15 to 20 days after flowering.

Six steps to scientific bagging of grapes

1. Preparation for bagging

The vines need to be trimmed a week before bagging, not only to thin the flowers and fruits, but also to sharpen them, taking care to cut off dead, stump, weak and insect-eyed branches. A spike needs to be left on each sturdy new shoot, and the secondary spike and sub-tip need to be trimmed in time.

Second, the bagging time

According to different cultivation methods, determine the appropriate bagging time. Bagging should be implemented sooner rather than later, after fruit setting through the whole ear, some varieties can be thinned, the fruit grows to the size of beans, about 15 to 20 days after flowering can be bagged. Late bagging is susceptible to the infection of pathogens such as charcoal, and grapes cultivated in greenhouses and sheltered from rain can be appropriately delayed compared with grapes in open fields.

3. Pharmaceutical prevention and control before bagging

Attention should be paid to the use of these drugs before bagging

1) It is best to carry out pesticide prevention and control within 1 week before flowering, systemic fungicide plus protective fungicide, such as thiophanate-methyl 800 to 1000 times mancozeb (complexed type) 800 times, mainly for the prevention and control of black pox, Wang Shouting cob brown blight, Jufeng varieties are particularly important this time;

2) Pesticides were treated within 1 week after flowering, and the main agents were: difenoconazole 2500 times + azoxystrobin 1500 times;

3) The second pesticide prevention and control after flowering is carried out at an interval of about 7 days, and the main agent is 1500 times of imazole + 1500 times azoxystrobin.

Improper use of pesticides can easily cause infection of germs such as gray mold after bagging.

Fourth, the bagging method

It should be noted that the bagging can only be carried out after all the sprayed agents have been dried. Before bagging, you need to open the selected bag by hand, and then put the whole ear into the bag from the bottom to the top, shrink the bag mouth to the ear handle and then seal it. It is recommended to choose a sunny day from 9 to 11 a.m. or from 2 to 6 p.m. for bagging.

Fifth, the choice of fruit bags

The selection of fruit bags is also a more important link, in the selection of fruit bags it is recommended to choose fruit bags with light weight, high transparency and good air permeability. Different varieties of grapes have different needs for the light transmittance of the bag, such as Kyoho grapes, in order to maintain the original color, a thicker yellow-brown kraft paper wrap should be used, while summer black grapes can choose white fruit bags with better light transmittance, and sunshine rose grapes can choose green fruit bags. If you plant it in a greenhouse, you can choose a thinner fruit bag, and if you grow it in the open air, you need to use a thicker fruit bag.

6. Check after bagging.

If it is found that the bag is broken or bulging (the bottom of the bag is not ventilated), it should be replaced in time. If it falls off and the bag mouth is loosened, it should be re-tied in time. At the same time, it is necessary to randomly check whether there is bacterial infection in the set from time to time, and if it is found that there is a disease, corresponding measures should be taken in time.

1. Grasp the bagging time.

According to the characteristics of the variety, the maturity period, the cultivation environment, the amount of annual rainfall, the early and late arrival of the rainy season, determine the bagging time. Generally, about 20-30 days after flowering, around the end of June, the bagging ends, too early or late fruit will hurt. Every year, from June to early July, the weather is hot, and the grapes are most prone to sunburn.

The best time to bag is before 11 a.m. and after 4 p.m.

Second, the choice of bagging fruit bags.

Choose bags according to the cultivation mode, and choose wood pulp paper bags with good waterproofness, bacteriometic function, good paper, strong kneading and good air permeability for field cultivation; For facility cultivation, you can choose one side of PP film, one side of non-woven fabric and high gloss efficiency bag. At present, the bags with better quality include Xiaolin fruit bags, Yiren fruit bags, Jiatian fruit bags, Tianjin non-woven fruit bags, and translucent paper bags in Sichuan. Xianyang Ruifeng fruit bag, Ruifeng fruit bag two kinds; One is that the paper is thinner, and the other is that the paper is thicker.

Early-maturing varieties are covered with thinner paper bags, and late-maturing varieties are covered with thicker bags.