How to Prune Grapevines When They Bloom
Grape pruning is a key technique in fruit tree management, directly affecting fruit setting rate and quality. Scientific pruning can not only optimize the tree structure but also distribute nutrients reasonably, achieving high and stable yields. Mastering the key points of pruning at different growth stages can keep the grapevine in the best growth condition.
Pruning Techniques During Grape Bloom Period
New Shoot Pinching
Pinch the fruiting branches 7-10 days before blooming, retaining 8-12 functional leaves. The main蔓 extension branch should be retained with 12-15 internodes, and the lateral branches should be pinched repeatedly, leaving 1 leaf. Using a 45-degree diagonal cut method, with the cut 2-3cm away from the bud eye, can effectively control vegetative growth and promote flower bud differentiation.
Flower Spike Shaping Standards
Strong branches should retain 2 flower spikes, medium branches 1, and weak branches should be removed promptly. 5 days before blooming, remove the tip of the spike (1/5-1/4), remove the lateral spikes and the first 3-4 small spikes at the base. For the Kyoho series, each spike should retain 50-60 small flowers, and for large spike varieties like Hongdi, 80-100 should be retained.
Pruning Management During Grape Bearing Period
Young Fruit Thinning Technique
Perform the first fruit thinning 7-10 days after flowering, removing poorly pollinated and malformed fruits. Maintain a spacing of 1.5-2cm between the fruit. For table grape varieties, keep 40-60 fruits per spike, and for wine grape varieties, keep 80-120. Use a professional fruit thinning shears to avoid pulling and damaging the pedicel.
Canopy Management During Expansion Period
Retain 12-16 internodes of the new shoot and tie them to the trellis, and leave 2 leaves on the lateral branches for pinching. Keep 1-2 reserve branches at the base of the fruiting branch, maintaining a spacing of 30-40cm. Remove 50% of the tendrils promptly to reduce nutrient consumption and maintain good ventilation and light exposure on the trellis.
Scientific pruning needs to be combined with water and fertilizer management. It is recommended to apply phosphorus and potassium fertilizers after pruning, and spray 0.3% urea + 0.2% potassium dihydrogen phosphate on the leaves. Different varieties require different pruning intensities; for example, the Kyoho series needs heavy pruning to control vigorous growth, while Xiabai can be pruned lightly. Regularly check the pruning results and adjust the management plan in a timely manner to achieve high-quality and abundant yields.