Detailed Explanation of Key Grape Spring Management Techniques
Spring is the season when grapes bud and unfold leaves, canes extend, and they send out clusters and bloom and set fruit. How to strengthen spring grape management and improve grape yield and quality is a matter of widespread concern among fruit growers. The following focuses on the main management work for grapes from February to April. 1. Late February to early March, budding stage: irrigate to promote bud break,...
Spring is the season when grapes bud and unfold leaves, canes extend, and they send out clusters and bloom and set fruit. How to strengthen spring grape management and improve grape yield and quality is a matter of widespread concern among fruit growers. The following focuses on the main management work for grapes from February to April.
1. Late February to early March, budding stage: irrigate to promote bud break, apply quick-acting nitrogen fertilizer.
Orchards with the necessary conditions should irrigate the entire orchard in good time at this stage to ensure uniform bud break. This is precisely when flower buds continue to differentiate and new shoots begin vigorous growth, requiring large amounts of nutrients, so apply decomposed human manure and urine mixed with 0.2% urea. This fertilization amount accounts for about 15% of the whole year.
2. March to mid-to-late April: bud rubbing, shoot thinning, flower cluster treatment and pest and disease control.
After winter pruning, the winter buds on the fruiting canes usually have 70-80% sprouted, and at this point attention should be paid to which buds to keep. Keeping too many buds easily wastes nutrients, makes the vine weak, and is not conducive to fruit set; but if too few buds are kept, it easily promotes vigorous cane growth and can cause severe flower and fruit drop, so attention must be paid to thinning buds and fixing shoots.
Bud rubbing: usually when multiple buds sprout on one fruiting cane, keep one bud every 15-20 cm, keep 2-5 new shoots per fruiting cane, and rub off the rest from the base. When rubbing buds, generally remove the flower-cluster-free bud or the weak bud from among double buds, leaving only one shoot per bud eye. Of course, to ensure yield, when the new shoot grows to 4-5 leaves, you may also decide whether to keep it based on whether its first tendril bears a flower cluster, but this wastes more nutrients.
Shoot fixing and cane tying: before flowering, the retained new shoots are pinched above the flower cluster leaving 5 leaves, while shoots without flowers are pinched leaving 8 leaves. After pinching, a large number of secondary shoots will sprout; keep only the top 1-2 secondary shoots and pinch them repeatedly leaving 2 leaves, and rub off all the other secondary shoots. At the same time, tie the canes in good time according to their growth.
Treatment of flower and fruit clusters: to ensure fruit set rate, manual methods are usually used to remove 1/5 of the tip of the flower cluster, and 0.3% boron fertilizer plus 0.5% urea is sprayed at flowering. Five days after flowering, for fruit clusters bearing more fruit, manual fruit thinning is carried out, and then bags are put on for protection.
Intertillage, weeding and disease control: begin disease prevention when grapes have sprouted 3-5 leaves, spraying once every 7-10 days, and especially strengthen spray protection after rain, and pay attention to intertillage and weeding. The main diseases to prevent at this stage are grape black spot, gray mold, rust, and so on. For example, black spot can be treated with DuPont Fusilade 8000-fold solution, and gray mold can be treated with Sumilex 1500-fold solution. Here, commonly used pesticides can also be used, such as carbendazim 800-fold, mancozeb 800-fold, zineb 800-fold, and other pesticides for control.