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

Potassium (K) is the most important element for fruit quality improvement. This study aimed at determining the best K fertilizer type that can promote grape growth and nutrient uptake.

2、Potassium deficiency reduces grapevine transpiration through decreased

Vines counter fruit mineral requirements by allocating potassium from canes to fruits and obscuring leaf mineral diagnostics. Plants require potassium (K) to support growth and regulate hydraulics. Yet, K's effects on transpiration are still speculated.

3、Effect of Foliar Application of Potassium Fertilizer on Yield, Fruit

In this study, liquid-based potassium fertilizer, ReaX TM (0-0-25), was applied to the leaves of grapevines four to five times at a concentration of 1.5% (v/v) during the growing seasons of two consecutive years.

PMSC

While fertilization generally improves vineyard performance, excessive or unbalanced applications can negatively affect grape and wine quality [10].

Foliar application of potassium to grapevine (Vitis vinifera, L.)

Foliar fertilization was applied three times during the growing season (31 May, 7 July, and 22 August 2014), and leaf samples were collected for leaf analysis before each application.

[PDF] Searching for an Optimized Potassium Fertilization in Grapevine

This study aimed to evaluate the effects of different K concentrations in the nutrient solution on berry composition, color development, and mineral concentration in leaves, petioles, and berries of fruit-bearing cuttings of Vitis vinifera L. cv. Tempranillo.

Potassium requirements in grapevine

Potassium regulates stomatal opening in leaves during periods of rapid vegetative growth, thereby controlling transpiration rate. This helps grapevines withstand hot, dry weather better and maintain steady photosynthesis.

Potassium Applications in Grapevines

Foliar applications of potassium during this time can be beneficial to brix development and berry sizing, especially if the Veraison petiole samples showed low or marginal K levels.

Effects of foliar application and fertigation of potassium on yield and

Our results showed that K nutrition improved yield and fruit quality of grapevine. Yield, fruit diameter and total soluble solids enhanced when the K requirements were given by a foliar spray combined with fertigation with K Leaf or NOP fertilizers.

Potassium deficiency reduces grapevine transpiration through decreased

Potassium deficiency leads to lower transpiration and productivity. Yet, internal mineral allocation compensates for fruit K uptake and masks biochemical indices or physiological proxies for K deficiency.

Applying high-potassium fertilizers during the grapevine leaf development stage is a critical management practice for enhancing plant health and improving fruit quality. During this phase, when new shoots begin to grow and leaves gradually expand, appropriate application of high-potassium fertilizers can significantly improve plant growth and fruit characteristics.

I. Physiological Characteristics of the Leaf Development Stage

1. Accelerated Growth Rate: This stage involves rapid shoot elongation, increasing the plant’s nutrient demands, particularly for potassium. Potassium promotes root development and strengthens stems.
2. Enhanced Photosynthesis: Potassium improves leaf photosynthetic efficiency, aiding carbon dioxide absorption and glucose production, which provides energy for fruit development.
3. Critical Period for Nutrient Accumulation: Proper fertilization during this stage lays the foundation for subsequent growth and fruit formation by supporting nutrient reserves.

II. Mechanisms of High-Potassium Fertilizer Action

1. Promotes Root Development: High-potassium fertilizers increase soil potassium availability, encouraging deeper root penetration and enhanced nutrient uptake.
2. Improves Stem Strength: Potassium strengthens stem elasticity and lodging resistance, stabilizing plants, reducing pest susceptibility, and boosting overall vigor.
3. Optimizes Nutrient Distribution: Potassium facilitates the transfer of nitrogen and other nutrients from older leaves to new foliage, ensuring balanced nutrition for healthy leaf growth.

III. Fertilization Recommendations

1. Timing: Apply before leaf development begins, adjusted based on local climate and soil type.
2. Dosage: Determine amounts according to vine growth and soil tests. Avoid overapplication to prevent root burn or excess salts.
3. Fertilizer Type: Use potassium-rich options like potassium sulfate or potassium nitrate for quick uptake and minimal environmental impact.
4. Application Methods: Choose trench, hole, or foliar spraying based on vine habits and soil conditions.
5. Precautions: Avoid excessive potassium use to prevent soil salinization. Coordinate with other fertilizers to maintain nutrient balance.

IV. Effectiveness Evaluation

1. Growth Indicators: Assess shoot growth rate, leaf color, and shape. Healthy, dark-green leaves without yellowing indicate successful fertilization.
2. Fruit Quality: Evaluate fruit size, color, sweetness, sugar content, and nutritional value. High-quality fruits typically have larger berries, vibrant hues, and elevated sugars.
3. Yield Analysis: Compare yield and quality data across treatments. Higher yields with superior fruit quality signify effective fertilization.

V. Comprehensive Management Strategies

1. Rational Crop Rotation: Avoid continuous grape planting to prevent soil depletion and disease buildup.
2. Scientific Irrigation: Ensure proper drainage and adjust watering based on weather and soil moisture to avoid root diseases.
3. Pest and Disease Control: Monitor vineyards regularly and use bio- or chemical controls to minimize pesticide reliance.
4. Pruning Management: Maintain proper pruning schedules to promote healthy growth, flower bud formation, and fruit maturation.

high-potassium fertilization during grapevine leaf development is an effective practice that enhances growth, fruit quality, and sustainable vineyard management. Mastering correct fertilization techniques is essential for grape growers.