2-4 Nutrients

Grapes need adequate nutrients to grow, especially nitrogen, phosphorus, potassium, calcium and magnesium. Different stages of growth require different nutrients. For example, more nitrogen fertilizer is needed during the germination stage to help branches and leaves grow, while more potassium is needed during the fruit expansion stage to make the fruit grow bigger. When grapes begin to change color, you should reduce nitrogen fertilizer and switch to phosphate fertilizer to increase sweetness. In addition, micronutrients such as boron and zinc have a significant impact on fruit set, so boric acid and zinc sulfate can be used to spray the foliage before and after flowering, which can increase fruit set by 15-20%. A base fertilizer, such as organic compost, is also needed to maintain the nutrients in the soil after harvest each year.