1、Nutrient solution with high nitrogen content, a suitable facilitator of

According to studies, grapes fertilized with N produced a yield two to three times higher than that of the conventional application without N irrigation (Stefanello et al., 2020).

2、Effects of Different Types of Potassium Fertilizers on Nutrient Uptake

Specifically, four types of K fertilizers (complex fertilizer, potassium nitrate, potassium sulfate, and potassium dihydrogen phosphate) were applied to grapevines grown in plastic pots, and then their effects on grape growth and nutrient uptake were explored.

3、Effects of Potassium

In this study, the effects of four potassium-containing fertilizers (complex fertilizer, potassium nitrate, potassium sulfate, and potassium dihydrogen phosphate) on sugar and organic acid metabolism in grape fruits were investigated.

4、Effect of nitrogen and potassium fertilization on productivity and

The amount of juice per berry increased and fruit firmness decreased in the high N-variants. The only effect of high K fertilization was an increase of total soluble solids and a decrease of acid concentration. Anthocyanin contents generally showed a high variability in the experiment.

Effects of foliar fertilizer additives on grape fruit quality and

In summary, potassium dihydrogen phosphate, as a widely used foliar fertilizer, can effectively improve the plant’s absorption efficiency of nutrients and further improve the quality of grape fruit when combined with adjuvants.

Effect of nitrogen and potassium fertilization on productivity and

High N- fertilization improved vegetative growth (leaf area, cane diameter) and reduced bud burst, bud fertility and fruitfulness. Excessive N-supply negatively affected yield per vine by...

Potassium Applications in Grapevines

High potassium levels in grape bunches are usually correlated to increased berry weight and brix at harvest. This is due to the critical role K plays in cell expansion and translocating sugars into the fruit.

Determining organic

Imbalanced water and fertilizer systems have limited the yield and quality of grapes in extremely arid areas. The combined application of organic (OF) and inorganic fertilizers (CF) has been proven to be one of the practical approaches to improving yield and quality.

Changes in the phenolic composition of grape berries during ripening in

The aim of this work was to evaluate the interactive effects of different rates of nitrogen and potassium fertilisation on the phenolic composition of grape berries during ripening.

A review on the influence of fertilizers application on grape yield and

Globally, fertilizers with different NPK ratios and micronutrients are used to achieve a better yield and desirable quality of grapes.

The grape berry expansion stage refers to the phase of rapid fruit growth and development, during which nutrient demand is particularly critical. At this stage, grapevines focus on photosynthesis, cell division, and fruit filling. proper fertilization is essential for grape growth and fruit quality.

Roles and Application of Nitrogen Fertilizers

1. Promoting Leaf Growth: Nitrogen is one of the three primary macronutrients for plants. It enhances leaf expansion, increases leaf area, and boosts photosynthetic efficiency. Adequate nitrogen during berry expansion ensures sufficient energy for fruit development.

2. Stimulating Flower Bud Differentiation: Moderate nitrogen promotes flower bud formation and blooming, which is vital for pollination and fruit set. Insufficient nitrogen can disrupt pollination and fertilization.

3. Impacting Fruit Quality: Nitrogen influences fruit size, sugar content, acidity, and aroma. Optimal nitrogen levels improve overall grape quality.

4. Preventing Excessive Vegetative Growth: Excessive nitrogen can lead to weak, elongated stems, reducing yield, fruit weight, and sugar content.

5. Soil Management: Avoid over-application of high-nitrogen fertilizers in vineyards to prevent excessive nitrogen concentrations in soil solutions, which may cause root hypoxia and disease risks.

Roles and Application of Potassium Fertilizers

1. Regulating Water Balance: Potassium improves water use efficiency and reduces water loss, helping plants cope with drought.

2. Enhancing Stress Resistance: Potassium strengthens drought tolerance and pest/disease resistance, especially under extreme temperatures or heavy rainfall.

3. Promoting Root Development: Potassium encourages deeper root growth, increasing root mass and nutrient/water uptake capacity.

4. Improving Fruit Quality: Potassium enhances fruit texture (e.g., crispness and sweetness), storage life, and transportability.

5. Preventing Potassium Deficiency Symptoms: During berry expansion, inadequate potassium leads to smaller, softer fruits with poor flavor. Proper potassium application is critical for maintaining quality.

Comprehensive Recommendations

Fertilization strategies during grape berry expansion should consider grape variety characteristics, soil conditions, and climate. Different fertilizer types (e.g., high-nitrogen/low-potassium, high-phosphorus/low-potassium, high-nitrogen/high-potassium) suit specific needs. For example:

• Cold-tolerant or drought-resistant varieties may require more nitrogen to support leaf growth.
• Acid-soil-loving varieties might benefit from additional phosphorus for root development.

Additionally, incorporate organic fertilizers (e.g., animal manure, green manure) to enrich soil structure and retain moisture and nutrients. Balance nitrogen-to-potassium ratios to avoid nutrient imbalances.

the berry expansion stage is a critical period for nutrient management. Scientific fertilization maximizes yields, enhances fruit quality, and strengthens market competitiveness.