Young fruit stage, fruit expansion stage and coloring stage. Silicon fertilizer can improve the ability of grapes to resist downy mildew infection before downy mildew appears.
Tips for fertilizing grapes:
High demand for fertilizer
Grapes grow vigorously, have lush branches and leaves, produce large amounts of fruits and require more soil. nutrients. Data shows that for 100 kg of fruit produced, vines must absorb 0.3 to 0.6 kg of pure nitrogen, 0.1 to 0.3 kg of phosphorus pentoxide, 0.3 to 0.65 kg of potassium oxide, 0.1 kg of magnesium and 0.05 kg of sulfur from the soil.
The demand for potassium fertilizer is large
Grapes are a typical potassium-loving fruit tree and need a large amount of potassium throughout the growing period . Its request ranks first among the three elements. , exceedingfar from that of other fruit trees, 1.7 times that of pears and 2.25 times that of apples. Under normal production conditions, the ratio of nitrogen, phosphorus and potassium requirements of grapes is 1:0.5:1.2.
Relatively sensitive to calcium
In case of calcium deficiency, grape leaves turn pale, the interveins and edges of young leaves turn green, the upper growth points of new shoots die, flowers shrink, and fruit sugar content Less accumulation, reduced hardness, transport intolerance, many crushed fruits, poor quality, short and thick new roots, slow plant growth and low yield. Therefore, calcium fertilizer should be applied timely and reasonably during production, and Bica medium element calcium and magnesium fertilizer should be sprayed on the leaves to improve the yield and quality of grapes.
Characteristicsstics of fertilizer requirements in stages
Grapes have different stages of growth and development throughout the year and require different elements and quantities. For example, a large amount of nitrogen nutrition is needed from budding to flowering, and sufficient boron fertilizer is needed during the flowering period. A large amount of phosphorus and potassium is required during berry development and flower bud differentiation. needed when the fruit ripens, and some amount of supplementation is still needed after harvest.