First, inflorescence and spike treatment
By thinning the inflorescence and fixing the length of the ear before bagging, the unnecessary loss of nutrients can be reduced, and at the same time, sufficient nutrition can be provided to the fruit grains on the ear as much as possible, thus promoting the fruit expansion and improving the commercial value of grapes.
1, sparse inflorescence
When the inflorescence is sparse, the strong and medium fruiting branches should leave one ear, and the weak fruiting branches should not leave one ear. For the double inflorescence branch, choose the ear with the same ear shape to keep it, and use? Stay, stay, stay big, stay strong and stay weak? As a matter of principle, keep the ear size moderate. For those with poor water and fertilizer conditions, weak growth, heavy load and many fruit branches, some inflorescences can be removed appropriately and the load should be as appropriate as possible.
2. Set the ear length
The ear length should be kept at 3 ~ 5cm at the tip of the ear one week before flowering, 6 ~ 8cm before and after flowering, and 12 ~ 14cm before bagging. This spike length can generally ensure the fruit yield of one kilogram to one and a half kilograms per spike, which is also the production requirement of high-grade grapes.
In the current fruit production, it is common that the ear is too big and the ear is too big and the grain is too small. Therefore, when thinning inflorescences and fixing panicle length, we should move closer to standardized management. According to different varieties, the standard of grain refinement is different. Summer black grapes generally need 60-80 grains, and summer black grapes have fewer single grains. Such as Hutai, Jufeng and other large-grain varieties, generally need 40-60 grains, which is also the basic requirement of high-grade grape production at home and abroad.
Second, the determination of bagging time and spraying before bagging
For fresh grapes, bagging can not only ensure the beautiful ear shape, but also prevent sunburn, bird damage and pests and diseases from harming berries. So, when is the best time to bag grapes? What should I do before bagging?
1, grape bagging time
Generally speaking, bagging work should be properly advanced, and the later, the more harmful factors. The best time for bagging grapes is about 15~20 days after physiological fruit drop. The best bagging time in northern China is generally around early June.
2. Spray before bagging
Before bagging, in order to completely remove the germs on the ear and ensure the aseptic bagging of grapes, it is necessary to spray pesticides and fungicides on the ear before bagging, and then bagging. The main diseases in this period are downy mildew, gray mold and anthracnose; In recent years, there are many pests, such as spotted wax cicada, winged moth and green blind stinkbug.
The recommended agent is difenoconazole+azoxystrobin+dimethomorph or procymidone. According to the occurrence of local diseases, it is very important to prevent downy mildew if it is serious and the climate is humid. If the humidity is high and some fruit trees tend to have gray mold, then procymidone should be increased. Pyrethroids are generally recommended for pesticides, which have the characteristics of low toxicity and wide insecticidal range.
Pay special attention to the following four factors when using drugs: First, using less emulsifiable concentrate will easily affect fruit powder; Second, using less chemicals such as triazole is easy to stop the growth of grape shoots and affect the fruit expansion; The third is to use powder medicine less, powder is used in the young fruit period, the fruit surface is not clean, and there are often black spots. If the fruit surface is clean, it is recommended to use more biological pesticides. Fourth, use ketone preparations as little as possible before bagging, which is easy to cause fruit surface damage. Putting ketone preparation after bagging is beneficial to leaf protection and prevention of downy mildew.
Third, the choice of bagging paper and bagging.
After application, generally speaking, the medicine should be bagged quickly after drying, in the morning and afternoon, and bagged the next morning after application in the afternoon. However, bagging can only be done after the medicine is dry. If the medicine is bagged before drying, it is easy to cause bagging disease. In principle, the interval between spraying and bagging should not exceed two days. In addition, if it rains after spraying, it can only be sprayed again after the weather clears up and bagged.
1, Selection of bagging paper
There are many kinds of grape bags in grape production, including non-woven paper bags, paper leather bags and paper bags. Non-woven paper bags are breathable, but expensive, and the surface is not very smooth after use; Paper-coated bag is a kind of bag with half film and half paper, and the bagging effect is not good, mainly because it will cause good coloring on one side and bad coloring on the other; The recommended bag in production is wood pulp paper bag, which is not only breathable, but also conducive to keeping the fruit surface smooth and colorful. The length of the selected paper bag should be greater than 35 cm and the width should be 20~25 cm.
2. Bagging grapes
When bagging, it is generally better to bag from 9 am to 1 1 and from 3 pm to 5 pm. This can avoid the high temperature between 12 and 2 pm and the dew time after 5 pm. High temperature bagging makes fruit farmers' friends prone to heatstroke. Another problem is that they get sunburned easily. Dew came up after five o'clock in the afternoon, and the humidity was relatively high. Bagging is not recommended. In addition, the bagging cycle should not be too long, and it is generally recommended to complete all bagging in 7~ 10 days.
Fourth, the management after bagging
Grape bagging is only a link in the production of high-grade grapes. After bagging, it is necessary to focus on preventing and controlling pests and diseases of new shoots and leaves. Protecting leaves is the most important thing, especially the prevention and control of pests and diseases is the premise to ensure the health of leaves.
1, pest control after bagging
Especially from June to August, it is the high incidence period of downy mildew, anthracnose, white rot and verticillium wilt. A simple and safe drug, which can be sprayed with Bordeaux mixture, not only has a good effect of leaf protection, but also has a low cost and is relatively safe. If the disease is serious, conventional chemical pesticides with low toxicity can be selected, such as prochloraz, dimethomorph, mycocarbendazim, and fluorosilicone, which should not only focus on the prevention and treatment of downy mildew, but also treat anthracnose, gray mold, white rot and other diseases.
Step 2 spray foliar fertilizer
During the grape coloring period, the mixed solution of 0.3%~0.4% calcium chloride or calcium nitrate +0. 1% boric acid can be sprayed on the leaves for 2~3 times every 7~ 10 days. Spraying 0.3%~0.5% potassium dihydrogen phosphate solution for 2~3 times before 1 month ripening can greatly promote the prevention of fruit cracking, sugar accumulation and berry coloring.
V unpacking and management after unpacking
All the work is to welcome the final harvest, and the bagging work after the grapes are ripe is also asked by the university. Different varieties, different varieties, the method of bag removal is also different. Therefore, the bag removal work should be flexibly applied in combination with varieties and regions, and it cannot be mechanically copied.
According to different regions, for colored varieties, in southern or eastern grape producing areas, it is generally necessary to remove paper bags about 20 days before harvesting, which is more conducive to full coloring of grapes. In the northern producing areas, because of the strong light during this period, it is not necessary to take down the paper bag before harvesting, and the color of berries can be adjusted with paper bags of different colors.
According to different varieties, green varieties such as Sunshine Rose, Jinyu, Victoria, etc. Because there is no coloring problem, these green varieties can be harvested without bagging before harvesting; However, for some red varieties, such as laterite, Rizamat, Bingmeiren, Jufeng, Hutai and Xiahei, in order to make the color bright and the fruit surface smooth, black, purple and red varieties are generally required to take off their bags before picking.
According to different grape varieties and regions, most of them are bagged 10~ 15 days before harvesting. If the humidity is relatively high and the temperature is relatively low during this period, the grapes can be colored quickly, and the bags can be removed about 10 days before picking; If the temperature is high during this period, especially when the temperature exceeds 35℃, the photosynthetic rate of leaves will be obviously weakened, resulting in slow coloring, and bags can be removed 15 days before harvesting.
3. Other management measures after picking up the bag.
After bagging, in order to promote uniform coloring, according to the situation, the old leaves can be removed and the ear direction can be turned to promote fruit coloring and increase sugar content.
Removing old leaves: when the grapes are about to mature, generally about 15 days before ripening, remove the leaves covering the ear and some aging leaves near the ear to increase the visibility of the ear and promote fruit coloring. Generally speaking, 25% of direct light can reach the ground. Orientation of ear rotation: if hedgerow cultivation is adopted, the ear of fruit can be rotated by 180℃, which can promote the uniform coloring of the whole fruit. Spread reflective film: after picking, spread a reflective film under the grape trellis to increase light scattering, thus promoting the uniform and bright color of the ear. In addition to the necessary soil, fertilizer and water management, these small management measures before and after bagging are all around the coloring of grapes and promoting the accumulation of sugar in berries, which is an important management measure to improve the sales quality and quality of grapes.