Identifying Grape Nutrient Deficiency Symptoms and Solutions
Grapevines need a variety of nutrients to grow. Once any one growth element is lacking, it will affect their growth, reducing yield and quality, and in severe cases it can cause the whole plant to die. Below, the editor brings you an introduction to common grape nutrient deficiency symptoms and their solutions.
1. Nitrogen deficiency
When grapevines lack nitrogen, the leaves turn yellow, the leaves are small and thin, new shoots grow slowly, the canes are thin and weak, the internodes are shorter, the fruit clusters are loose, and the yield is lower. When nitrogen is deficient, you can promptly apply a quick-acting nitrogen fertilizer as a top dressing to maintain nitrogen levels, or you can apply foliar fertilizer; generally, a 0.5% urea solution is used for foliar spraying, with good results.
2. Phosphorus deficiency
When grapevines lack phosphorus, the leaves curl and purple-red spots appear, the shoot tips grow poorly, the leaves drop early, and flower and fruit drop is fairly severe. If phosphorus deficiency is found, promptly use a 0.2% superphosphate extract or a 0.2% monopotassium phosphate solution for foliar spraying, which can very quickly resolve the phosphorus deficiency in the plant.
3. Potassium deficiency
When grapevines lack potassium, the leaf margins and veins lose their green color and turn yellow, gradually becoming yellow-brown patches; in severe cases, the leaf edges appear scorched, the canes are brittle and short, the berries are fewer, and the acidity is higher. When potassium is deficient, you can apply plant ash or spray a 0.2% monopotassium phosphate solution, with good results.
4. Calcium deficiency
When calcium is deficient, pinhead-sized spots appear on the leaf margins, flower and fruit drop is fairly severe in the early stage, the fruit skin is thinner, and fruit cracking is likely to occur in the later stage. To address calcium deficiency in the plant, you can mix an appropriate amount of superphosphate into the base fertilizer to maintain calcium levels; when calcium is deficient during the growing period, you can spray a low-concentration superphosphate solution.
5. Boron deficiency
When boron is deficient, new shoots are thin and weak, the internodes become shorter, the tips die back, and irregular yellow spots appear on the leaves near the flower clusters, which drop very easily. The leaves are small and deformed, and after flowering the red-brown corolla drops very easily, resulting in a low fruit-setting rate. If boron deficiency is found in the plant during the flowering period, you can spray a 0.2% borax solution.
6. Zinc deficiency
When grapevines lack zinc, the internodes of new shoots shorten, the leaves become smaller, and patchy chlorosis appears on the leaves; sometimes sparse fruit clusters and uneven berries also appear. If zinc deficiency is found before flowering, you can spray a 0.1%-0.2% zinc sulfate solution, which can very quickly maintain zinc levels and allow flowering and fruit setting to proceed normally.
The above is an introduction to grape nutrient deficiency symptoms and solutions. We hope it can help you. To learn more related knowledge, please stay tuned to us.