Grape Fertilizing Time, Fertilizer Selection and Foliar Spraying Techniques Explained in Detail

Grape is also known as Putao, Caolongzhu, Cizi Cherry, Bodhi Seed, and Shanhulu; it flowers from April to May and fruits from August to September. It is cultivated all over the world.So when is the right time to fertilize grapes? What fertilizer is best? What are the foliar spraying techniques?

When is the right time to fertilize grapes?

Because grapes are fertilizer-loving plants, more fertilizer means vigorous growth and more fruit. According to the growth, fruiting and fertilizer requirements of mature grapes, more nitrogen fertilizer should be applied in the early stage and more phosphorus fertilizer in the later stage, with at least 4 applications throughout the year.

1. The first application is bud-promoting fertilizer, after the grapes are uncovered from the soil;

2. The second application is fruit-swelling fertilizer, after the grapes set fruit, in mid to late July;

3. The third application is ripening-promoting fertilizer, around the Beginning of Autumn, before the fruit ripens;

4. The fourth application is vine-nourishing fertilizer, after the grapes are harvested; for early and mid-season varieties, in mid to late August or early September, and for late-maturing varieties, in late September or early October.

What fertilizer is best for grapes?

1. Base fertilizer for grapes: mainly organic fertilizer, and the amount should account for 60%-70% of the total annual fertilizer application. Apply 3000-5000 kg of barnyard manure or compost per mu. If using commercially available dried chicken manure, the amount is 700-1000 kg, and 30 kg of compound fertilizer can also be added. When fertilizing, note that the organic fertilizer must be fully decomposed.

2. Topdressing for grapes: carried out during the growing season to promote plant growth and fruit development.

3. Bud-promoting fertilizer: applied before the buds begin to sprout in early spring. Mainly quick-acting nitrogen fertilizer. After topdressing is completed, irrigate immediately to promote uniform budding. Urea or decomposed human feces and urine can be applied; urea at 0.1-0.4 kg per plant, or liquid human feces and urine at 8-10 kg per plant applied with irrigation.

4. Pre-flowering fertilizer: apply 7-10 days before flowering, preferably a nitrogen-phosphorus-potassium compound fertilizer, 0.1-0.15 kg per plant.

5. Fruit-swelling fertilizer: at this stage, fertilization should combine quick-acting nitrogen fertilizer and compound fertilizer, with urea at 0.1-0.5 kg per plant and nitrogen-phosphorus-potassium compound fertilizer at 0.1-0.5 kg per plant.

6. Color- and sugar-enhancing fertilizer: refers to fertilizer applied before or at the early stage of fruit color change, mainly phosphorus and potassium fertilizer. Potassium sulfate at 0.2-0.4 kg per plant can be selected.

What are the foliar spraying techniques for grapes?

1. Suitable period: Generally speaking, foliar fertilizer can be applied throughout the entire growing season of grapes. It is best to spray “shoot-promoting fertilizer” before new shoot growth, spray “flower- and fruit-stabilizing fertilizer” during flowering and fruit set, and spray “fruit-strengthening fertilizer” during the fruit enlargement stage. Spraying boron during the flowering period gives good results; spraying rare earth micro-fertilizer at the early stage of berry softening has a strong effect.

2. Weather and time: Foliar spraying is greatly affected by wind, temperature and humidity. Within a certain range, the higher the temperature, the faster the leaves absorb fertilizer; the greater the humidity, the more fertilizer they absorb; the lower the wind speed, the longer the fertilizer solution remains moist on the leaves, the more fertilizer is absorbed and the less is lost to drift. To improve the effect of fertilizer spraying, it is best to choose a windless cloudy day for spraying. On sunny days, it is best to do it in the morning or evening when the temperature is suitable (18℃~25℃), the humidity is relatively high, and evaporation is low.

3. Method: The cuticle layer of young grape leaves is thinner than that of old leaves, so more fertilizer solution penetrates; the underside of the leaf has more stomata than the upper side, so absorption is faster. Therefore, foliar fertilizer application to grapes should focus on young shoots, young leaves and the underside of leaves. Spraying should aim for fine droplets to facilitate uniform and dense coverage, spraying until the leaves are completely moist, with the fertilizer solution about to drip but not falling. According to need, multiple fertilizers can be mixed and sprayed, and they can also be mixed with pesticides (including plant growth regulators) to simultaneously prevent diseases and pests.