The pruning technology of grape vine in winter
In fruit bearing period, the grape vine will grow slowly. Due to the large amount of fruit bearing, branches will be drooped, besides, the thin and weak branches will be difficult to form flower bud. Therefore, proper heavy pruning is needed, in which strong branches should be cut less and weak branches should be cut more as well as adjust the relationship between plant growth and fruit bearing, thus it can keep robust tree vigor and extend fruit bearing period age limit. Regarding the elongated shoot of main branch and lateral branch, proper heavy short-pruning is needed, in which the branches will be cut 1/2-2/3. If the main branch and lateral branch are in droopy state, choose one robust branch from the back part as the main branch and remove the original one. Regarding the perennial temporary branch and droopy branch, they should be cut back when the branchlets are strong. Part of the inserted medium and long branches will be cut short, part of them will be reserved and will not be cut short as well as part of them will be left for fruit bearing, thus it can ensure the output. The long and medium fruit spur that grows inside of the crown should be cut short frequently, while part of the perennial branches that grow outside of the crown should be cut back. Thus it can improve ventilation and light transmission conditions.
During the blossom and yield fruit periods of grape, we should pay attention to prevent the plant disease and insect pests. Downy mildew, anthracnose, sphaceloma ampelinum, cladosporium cucumerinum, geotrichum candidum, aphid and red spider will do harm to leaves, flower buds and fruits, in which most of the damages will be caused by overwintering pests. If these kinds of overwintering pests can be wiped out in time, it will reduce the damage in the blossom and yield fruit period in the second year when the air temperature rises again. Therefore, after the fallen leaves period of grape, we should pay attention to prevent the overwintering pests. Below are some specific prevention methods: clear the orchard in time after the grape fallen leaves period in winter, clear all of weeds, deadwoods, fallen leaves and fallen fruits in the orchard as well as gather them and deeply bury or burn up outside the orchard. Afterwards, spray 1500 times liquid 3.2 percent of abamectin insecticide, 1000 times liquid 80 percent of thiophanate-methyl mixed liquor or 1500 times liquid 48 percent of chlorpyrifos and 1000 times 80 percent of carbendazim mixed liquid or 0.8-1 baume degree lime sulphur aqueous solution one time every 15-20 days (totally 2-3 times). Evenly spray these pesticides on all of the stems until the droplet starts to drip. In order to improve the prevention effect, the drug is forbidden to be used in windy weather. If the drugs are washed by rain after four hours of spraying, it should be sprayed again.