How to Prune Grapevines in Spring
Early spring is a crucial period for grapevine management. Scientific pruning techniques not only optimize the plant's form but also effectively improve fruit setting rate and quality. This article will detail how to rejuvenate grapevines through pruning with four core operational steps for growers.
One, Four Core Steps for Spring Pruning
1. Precision Bud Removal Operation Norms
When the buds grow to 2-4 centimeters, they enter the optimal period for bud removal. Adopt the 'three keep, three remove' principle: keep the main bud and remove the secondary ones, keep the strong bud and remove the weak ones, and keep the low buds and remove the high ones. It is particularly important to note that for old vines, keep 1-2 buds per node, and for new vines, keep only 1 plump bud per node. This method can save more than 30% of nutrient consumption.
2. Scientific shoot Management Process
The first shoot removal is carried out 20 days after the new leaves unfold, focusing on removing crowded new shoots with a spacing of less than 15 centimeters. The second shoot removal should be combined with the observation of inflorescences, keeping strong branches with inflorescences and pruning crossed and inward-facing branches. It is recommended to keep the number of branches within 8-10 per square meter of trellis to ensure ventilation and light.
3. Key Points of Differential Pinching Technique
Implement分级 treatment based on the diameter of the branches: weak branches with diameter <0.6 cm should be pinched at the 5-leaf stage, retaining 2 functional leaves; medium-strong branches with diameter 0.6-1 cm should be pinched at 6 leaves; strong branches with diameter >1 cm can be treated up to 3 days before flowering. Be sure to apply wound protectant promptly after pinching to prevent pathogen invasion.
4. Detailed Flower Thinning Strategy for Yield Increase
Implement the 'three observe' flower thinning method during the inflorescence separation stage: observe the branch strength (keep 2 clusters for strong branches, 1 for medium, and none for weak), observe the quality of inflorescences (remove secondary clusters and the tip of the cluster), and observe the spatial layout (maintain a distance of more than 20 cm between adjacent clusters). Spraying 0.2% boron fertilizer can increase the fruit setting rate by over 15%.
Two, Complementary Management to Enhance Effects
After pruning, immediately clean the garden and spray lime sulfur. At the same time, apply high-phosphorus water-soluble fertilizer. It is recommended to follow the 'one cut, two tie, three supplement' care trilogy: complete the tying of the vines within 3 days after pruning, supplement amino acid foliar fertilizer 5-7 days later, and implement precise water and fertilizer management with a drip irrigation system.
Through the above systematic pruning management, the photosynthetic efficiency of grapevines can be increased by 40%, and the fruit sugar content can be increased by 2-3 degrees. It is recommended to perform supplementary pruning once a month, promptly removing sprouting branches to maintain trellis ventilation. Mastering these key technologies will certainly lead to a bountiful harvest in your vineyard.