Grapevine Management Methods and Pesticides for Controlling Borer Pests
Grapes are a fairly common fruit with very thin skin and a sweet-and-sour taste that is well balanced, which is why they are so well liked. Many people now enjoy growing grapes, but during the growing process, grapes may also come under attack from pests, most commonly the borer. So what should be done when this happens?
How to manage grapevines
1. Clearing the vineyard: Be sure to thoroughly clean the vineyard, mainly to completely clear away the broken branches and fallen leaves left after picking the grape seedlings in the previous autumn, as well as weeds and dropped grape berries from diseased vines and other debris. After clearing, these wastes can be buried deep or simply burned.
2. Watering: Especially in dry regions, watering is very important. In regions with rainy weather and high soil moisture, decide according to the situation; if the soil is moist enough, there is no need to water. This can promote thicker, stronger new shoots on the grape seedlings.
3. Spraying: When the winter buds of the grape seedlings are about to sprout, spray 3 to 5 rounds of lime sulfur mixture at Baume degrees plus 200 times sodium pentachlorophenate, and spray the pesticide thoroughly on the vines, the ground, the posts and the wires. In vineyards where green plant bugs occur, spray an insecticide once from bud break to before leaf expansion.
What pesticide to use for grape borers
1. Spraying to control borers must seize the peak adult emergence period and the larval hatching period. You can choose 1.8% Abamectin EC at 2500 to 3000 times dilution, Bt wettable powder at 800 times dilution, which should be applied early or chosen as an option, or 21% fenvalerate-malathion EC at 2000 times, 20% fenvalerate or 10% fenpropathrin-malathion EC at 1000 times, or 2.5% lambda-cyhalothrin EC at 3000 times dilution.
2. Or 10% diflubenzuron suspension concentrate at 2000 times dilution, or 20% fenvalerate EC at 3000 times dilution, or 5% esfenvalerate EC at 3000 times dilution, or 10% bifenthrin EC at 3000 times dilution, or 5.7% beta-cyfluthrin EC at 2500 times dilution, or 2.5% deltamethrin EC at 3000 times dilution, or chlorbenzuron No. 3 suspension concentrate 100.
How to prune grapes
1. Long-cane pruning. Long-cane pruning generally uses the double-cane renewal method. Below the fruiting mother cane, select and keep one cane as the renewal mother cane; the renewal mother cane keeps 2—3 healthy buds, and the fruiting mother cane keeps 6—12 buds, prompting new shoots to emerge, which can flower and bear fruit that same year. From the renewal mother cane, 2 new shoots emerge (if 3 emerge, remove one); if flower clusters form on them, they should be removed to reduce nutrient consumption and encourage the branch tissues to become full and solid. At winter pruning the following year, cut off all of that year's fruiting mother canes. The new shoots on the upper part of the renewal mother cane still keep 6—12 buds as fruiting mother canes, and the new shoots on the lower part keep another 2—3 buds as renewal mother canes. When selecting and keeping renewal mother canes, try to choose ones closer to the main trunk to control the speed at which the fruiting position rises year by year.
2. Short-cane pruning. First grow a cane about one meter long, and let multiple fruiting main canes emerge from the main cane. At winter pruning, keep 2—3 buds on each fruiting mother cane. After shoots emerge in spring, select one upper branch as a fruiting branch and one lower branch as a renewal branch, and do not let it bear fruit. At winter pruning, cut off all the fruiting branches, and keep 2—3 buds on the renewal branch.
3. Medium-cane pruning. Medium-cane pruning and renewal methods are basically the same as short-cane pruning; the difference is that the fruiting mother cane keeps more buds, generally 4—5 buds. In addition, when pruning, cut out dense branches, weak slender branches, pest-damaged branches and dry dead branches.
Fertilization methods for grapes at each growth stage
1. Bud-promoting fertilizer: Generally applied before grapes start growing. This time, nitrogen fertilizer is the main type, aimed at promoting uniform sprouting, thick and large leaves, and large, strong flower clusters. If the vine is excessively vigorous and spring is not very dry, this fertilizer and watering can be omitted to avoid excessive elongation of new shoots.
2. Berry-sizing fertilizer: Applied after grapes set fruit, that is, when the berries are about the size of mung beans, or at the latest when they are the size of soybeans. This fertilizer is mainly nitrogen, together with phosphorus and potassium fertilizers. You can apply a high-nitrogen compound fertilizer, or an ordinary three-element compound fertilizer, and add nitrogen fertilizer such as urea as appropriate. This application should be heavy and can account for about 50% of the chemical fertilizer applied in the whole year.
3. Ripening fertilizer: Applied in two rounds. 20-30 days before ripening, apply a high-potassium water-soluble fertilizer, and apply it once more when the grape berries begin to soften but have not yet colored. This fertilization is very important. After applying the berry-sizing fertilizer, many fruit growers do not apply the ripening fertilizer again, which may cause poor fruit coloring (commonly known as water-pot disease) or, due to fertilizer deficiency, poor grape resistance, susceptibility to disease, and high yield without a good harvest. Or poor coloring, low sugar content, and the inability to sell at a good price, and so on. You can directly apply a functional fertilizer, a macro-element water-soluble fertilizer for coloring (a high-phosphorus, high-potassium type is recommended, also containing the trace elements boron and zinc).
The most common way to control grape borer damage is to use pesticides, and there are many application methods. Before spraying, be sure to do the dilution work properly. After planting grapevines, strengthen the cleaning work in the vineyard, and also water in time to ensure their growth.