Timing of High-Potassium Fertilizer Application for Grapes and Analysis of Grape Potassium Content

AbstractTiming of potassium fertilizer application for grapes: After fruit set and until the veraison stage, a monopotassium phosphate solution can be sprayed on the leaves, once every 7-15 days, for 2-3 consecutive applications, with spraying times before 9 AM and after 5 PM. Grapes have a relatively high potassium content, with 104-151 mg of potassium per 100 g of grapes, and they also contain relatively large amounts of minerals and trace elements.

I. Timing of Potassium Fertilizer Application for Grapes

1. Potassium fertilizer is very important throughout the entire growth stage of grapes, especially during the fruit growth period when the demand is greater, so grapes have the fine reputation of being a “potassium” crop. Applying potassium fertilizer can promote grape fruit enlargement and accelerate ripening, while also improving quality and storage tolerance, as well as enhancing resistance to cold, drought, high temperatures and pests and diseases.

2. After fruit set and until the veraison stage, depending on the orchard soil fertility, 5-10 kg of potassium sulfate can be applied as a top dressing per mu of vineyard, or an appropriate amount of monopotassium phosphate solution can be sprayed on the leaves, once every 7-15 days, for 2-3 consecutive applications.

3. Foliar spraying of monopotassium phosphate solution helps promote grape enlargement and earlier ripening, while also accelerating the aging of branches and vines, significantly improving grape resistance, and having a clear inhibitory effect on major diseases such as grape anthracnose and black pox.

4. The suitable time for foliar spraying is before 9 AM and after 5 PM. Spraying is not suitable at midday when temperatures are too high. When spraying, both the front and back sides of the leaves should be sprayed evenly, and 60 kg of fertilizer solution can be sprayed per mu.

II. Is the Potassium Content of Grapes High

1. Grapes contain relatively high potassium. Because grapes have different varieties, the potassium content per 100 g of grapes is 104-151 mg, which is relatively high among fruits. Grapes also have the effects of supplementing qi and blood, benefiting the liver and kidneys, promoting body fluid production, strengthening bones and muscles, supplementing qi and blood, relieving cough and irritability, and promoting urination.

2. They are mainly used for symptoms such as lung deficiency cough, palpitations and night sweats, qi and blood weakness, rheumatic arthralgia, strangury, and edema, and can also be used as auxiliary treatment for conditions such as shortness of breath and fatigue, spleen deficiency and weak qi, edema, and difficult urination.

3. Grapes contain relatively large amounts of minerals and trace elements, such as calcium, iron, potassium and so on. Generally, after grapes are made into raisins, the sugar and iron contents become relatively higher, and raisins are also an excellent tonic for children, women and those with weak constitution and anemia.

4. Research shows that eating an appropriate amount of fresh grapes every day can effectively prevent the occurrence of cardiovascular and cerebrovascular diseases, and is also beneficial to the health of patients with focal ischemic heart disease or atherosclerotic heart disease.

5. Moreover, the resveratrol in grape skins and the proanthocyanidins in grape seeds are both higher than in other parts of the grape, and also higher than in most other fruit trees. Therefore, they have extremely high medicinal value and have become an important worldwide commodity that is both nutritional and medicinal.