Detailed Explanation of Key Points for Growing Purple Sweet Seedless A17 Grapes
Choose a plot of alkaline sandy soil or sandy loam on high ground to establish the vineyard, and deep-plow and apply sufficient basal fertilizer, digging a trench 50cm wide and 50cm deep. Then select a vigorous shoot from the main vine as the main shoot and plant it into the soil. After successful planting, carry out basic management tasks such as watering and fertilizing, pruning, trellising, and pest and disease control, and it will bear fruit.
Key points of Purple Sweet Seedless A17 cultivation techniques:
1. Establishing the vineyard
Establish the vineyard on sandy soil or sandy loam with high terrain, sufficient sunlight, annual rainfall below 700mm, deep soil layer, irrigation and drainage conditions, good drainage, and a pH value of 7-8. Before planting, dig planting trenches 60-80cm in length, width, and depth, place the topsoil into the bottom layer, then apply decomposed organic fertilizer or organic biological fertilizer. After filling, irrigate, and once the soil surface subsides, backfill with soil to level it.
2. Small trellis shaping and pruning
(1) The year of planting. Keep only 1 strong branch shoot per plant to cultivate as the main vine, remove excess buds, and promptly pinch off newly grown tendrils. When the main vine reaches 1m, pinch the tip, and keep 2-3 leaves on the sprouted lateral shoots and repeatedly pinch the tips. Carry out winter pruning from late October to early November, cutting back the main vine at 1.0-1.2m where the thickness is 1.2-1.5cm, and remove all lateral shoots on the main vine.
(2) The 2nd year of planting. After budding, leave no branches within 50cm of the main vine from the ground, select a vigorous shoot as the main shoot, continue its extended growth, and pinch the tip when it reaches 1.2-1.5m. After pinching, when the new shoot sprouting from the 1st bud reaches 0.4-0.5m, carry out the 2nd pinching, and thereafter keep 3-4 leaves and repeatedly pinch the tips; during winter pruning, cut and retain the current-year main vine at 1.0-1.2m.
(3) The 3rd year of planting and thereafter. Follow the management method of the 2nd year, continue cultivating the main vine, and expand the trellis surface.
3. Flower and fruit management
For 2-year-old strong trees, retain 1 inflorescence on each fruiting branch, keep 3-4 inflorescences per plant, and after thinning the inflorescences, keep the front inflorescence. After the inflorescences separate and before flowering, carry out inflorescence shaping, pinch off the branched shoulders at the base of the inflorescence, and then according to the size of the inflorescence pinch off the tip of the inflorescence (accounting for about 1/5-1/4 of the inflorescence length). After fruit set, manage the fruit clusters promptly; generally, when the berries are as large as mung beans, carry out the 1st fruit thinning, manually cutting off damaged berries, small berries, diseased and pest-damaged berries, inward-growing berries, and excessively dense and excessive berries, so that the fruit cluster forms a cylindrical or conical shape.
4. Fertilizer and water management
(1) The year of seedling planting. At planting, apply 4000-5000kg of decomposed organic fertilizer per 667m2. Apply topdressing frequently, in small amounts, and shallowly, pay attention to the ratio of N, P, and K fertilizers, and apply fertilizer 4-5 times combined with irrigation.
(2) 2 years after seedling planting. In mid-April, that is, before budding, irrigate with water to promote budding, and broadcast 10kg of urea or nitrogen-containing compound fertilizer per 667m2; around May 10, irrigate with pre-flowering water, mainly with urea, appropriately increasing P and K fertilizers, and cover with basal fertilizers such as sheep manure; in mid-June, irrigate with water to promote fruit development, with the same amount and types of fertilizer as before flowering; around July 20, irrigate with water for coloring and fruit swelling, mainly applying phosphorus and potassium fertilizers, and foliar spraying can also be used; on August 20, irrigate with pre-harvest water.
5. Application of plant growth regulators
7-10d before flowering, apply a 40000-fold Qibao solution, which can significantly elongate the fruit cluster, make the cluster loose, and reduce squeezing between berries; 15d after flowering, treat the berries with a 12500-fold Qibao solution, which can significantly promote berry enlargement.
6. Bagging fruit clusters
Bagging fruit clusters can prevent diseases, insect pests, bird damage, pollution, and so on, and improve the overall quality of the fruit. This variety colors easily under scattered light conditions and can fully complete the entire coloring process inside the bag, so there is no need to remove the bag in production, making it very suitable for bagged cultivation. Generally, around 20d after flowering, shape the fruit clusters and thin the berries, and bagging is suitable when the berries are the size of soybean grains. Before bagging, spray the whole vineyard evenly with 1 round of fungicide, especially the fruit clusters, which should be sprayed evenly and thoroughly; if there are insect pests, add insecticide when spraying, wait for the liquid to dry, and then begin bagging. White paper bags can be selected. They can be harvested with the bag and stored with the bag.
7. Disease control
Strengthen management, cultivate strong trees, enhance tree resistance, and keep the orchard clean. After the grapes are uncovered from the soil, spray the whole tree with 3-5 degrees lime sulfur mixture to reduce overwintering disease sources. In rainy years, spray Bordeaux mixture earlier to prevent diseases; before and after flowering, spray 50% carbendazim 1000-fold solution + 50% thiophanate-methyl 800-fold solution 1-2 times to prevent the occurrence of grape gray mold. After fruit set, according to the occurrence of diseases, alternate the use of protectants and fungicides.
The above is the relevant introduction to Purple Sweet Seedless A17 growing techniques, and we hope it is helpful to everyone.