Best Nutrient Management In Grapes During Adverse Climate Conditions

Grape Growing in India: Overview

Grapes (Vitis vinifera) belonging to the Vitaceae family, originated in Western Asia and Europe. It was introduced to India by the Persian invaders in 1300 A.D. It is a temperate crop which has got adapted to sub-tropical to tropical climate conditions of India. Grapes occupy a predominant position in terms of world fruit production, with approximately 16% share of the global fruit production.

Grapes hold significant importance as a fruit crop in India, encompassing an area of 155.30 thousand hectares, which constitutes 2.24% of the total area in the year 2021-22. Karnataka, with a notable share of 24% in the same year, stands as the second-largest grape producer, according to data from APEDA (2021). Leading districts of grape production in Karnataka are Vijayapura, Bagalkot, Chikkaballapur, Belgaum, and Bengaluru Rural (formore general information on growing grapes in India, see “Growing Grape Crop Nutrition advice”). Global viticulture faces colossal challenges from unchecked climate change, as growing regions grapple with mounting pressure. The interplay of pedo-climatic and topographic factors significantly impacts table grapes and wine quality and production. Altered precipitation patterns and intensified extreme weather events, such as high temperatures and heat waves, detrimentally affect crop productivity.

The weather parameters, including maximum and minimum temperature, relative humidity, rainfall, and wind speed, exert a notable influence on grape cultivation. It affects its growth and yields, as well as the prevalence of pests and diseases, water requirements and fertilizer requirements. Weather anomalies may make crop damage and soil erosion worse. Understanding and managing these weather effects are crucial for optimizing grape yield and ensuring vineyard productivity and quality.

How Climatic Factors Affect Nutrient Uptake and Quality of Grapes?

Nutrient management is an important issue for wine grape growers since it impacts grapevine growth, fruit set, crop yield, berry composition and ultimately the quality of the wine. Grapevine nutrient needs are moderate, but unbalanced fertilization may lead to both undesired effects on wine quality, including a lack of acidity in wines made from grapes with an excessive potassium (K) supply, and to environmental impacts as a consequence of groundwater nitrate contamination.

Majority of the vineyards are either raised on heavy soils or on marginal lands. Though grapes can be cultivated on varied soil conditions, deep and well-drained soils with pH range of 6.5 – 8.0 is ideal. The soil pH above or below this range is known to restrict availability of some nutrient elements and thus inhibit growth and development. The weather is mostly dry with less number of rainy days (30- 40 days) during the year.

Favourable rooting environment and proper understanding of the phenology is key to efficient water and nutrient management. Being double pruned and single cropped, the nutrient requirement differs between both the pruning seasons. However, this region suffers from abiotic stress namely moisture and salinity stress. Normally, potassium, magnesium, iron, zinc and sometimes boron deficiencies are observed in our vineyards. Apart from these, toxicity of sodium can also be observed due to saline irrigation water containing sodium more than 100ppm.

Role of Nutrients During Berry Development Stage in Grapes

Primary Nutrients:

Nitrogen:

• During berry development, Nitrogen Based Fertilizers help the plant build a strong photosynthetic structure, which is essential for sugar and energy production.
• N plays a key role in the synthesis of proteins which are directly involved in growth and yield.

Phosphorus

• Phosphorus promotes the development of a good root system – a prerequisite for flowering and hence, the overall number and maintenance of fruits.
• Essential for appropriate energy management in the plant. Enhances cell division.

Potassium

• Enhances the transport of sugars to the fruits. A cofactor of tens of enzymes. Regulates water management, mainly through stomata aperture.
• Enhances the sugar content of the fruit. Potassium reduces susceptibility to many kinds of abiotic and biotic stresses. Improves deep green fruit colour, firm flesh, shape, and overall yields.

Secondary Nutrients:

Calcium

• Promotes cell-wall stability, providing the plant with a strong structure and resistance to diseases.
• Adequate calcium prevents blossom-end rot (BER). It also delivers improved shelf life.

Magnesium

• It is the central part of the chlorophyll molecule, playing a key role in photosynthesis. Increases Fe utilization.
• Magnesium is the carrier of phosphorus in the plant. It is both an enzyme activator and a constituent of many enzymes. Adequate Mg application helps obtain a deep green fruit colour.

Micronutrients:

Iron

• Essential for proteins and chlorophyll synthesis. Iron is an important factor in many enzymes, associated with energy transfer and the respiratory system.

Manganese

• Improves translocation of sugars and carbohydrates, pollination and seed production. Cell division and cell-wall formation are both related to Ca uptake and use.

Zinc

• Zinc is required for the production of auxin, an essential growth hormone. Promotes proteins and chlorophyll synthesis. Necessary for starch formation and proper root development.

Nutrient Management in Grapes During Bunch Development

The nutritional requirement of vines differs with crop growth stages. The grapevines are drip irrigated and the same technique can be efficiently used for delivering nutrients based on crop growth stages at split intervals and on demand. Fertigation allows the application of nutrients precisely and uniformly to the wetted volume where active roots are concentrated. This improves the fertilizer use efficiency as compared to conventional practice of direct application of fertilizer to the soil. The nutrient doses given for fertigation should be modified according to the petiole nutrient status of the vines and soil as over the years nutrient build up is there in the soil. For better results fertigation interval should not be more than three days and nutrient doses should be applied in equal splits depending upon the number of days in a particular stage. Nutrient present in the irrigation water and the contribution of organic manures should also be taken into consideration.

Majority of the grape growing areas in Karnataka are alkaline in reaction and also calcareous. The grapevines are able to tolerate calcium carbonate level upto 5%. Calcium deficiency in calcareous soils is not common and do not require specific fertilizer application unless vineyard soil has high pH or sodium. Certain climatic conditions (cold or rainy) or nutrient imbalance in soils may cause Ca deficiency in fruits (berries) which can be corrected using FertiFlow 12-6-22+12 CaO provides a balanced supply of nitrogen, potassium, and calcium, which strengthens berries, enhances cell division, and supports plant structure. Applying 5 kg per acre of FertiFlow 12-6-22+12 CaO by three doses and also to increase nutrient uptake and quick recovery of nutrient deficiencies foliar application of Nutrivant fruit 12-5-27+8 CaO 5 gram per liter two times.

Magnesium application must be done only if needed based on petiole test value, since in many vineyards ground water irrigation source may add substantial quantities of Mg in soil. To maintain magnesium level in soil, apply MagPhos 0-55-18 + 7 MgO 5 kg per acre two times. Among the micronutrients, zinc and iron are the most commonly deficient nutrients to recover from this foliar application of Select zinc 1 gram per liter and Select Fe EDTA 0.5 gram per liter.

Potassium is by far the major cation related to berry ripeness and its concentration in grapes is related to the must acidity. In a climate change scenario, this cation becomes very relevant since high temperatures could possibly increase K levels. Potassium is involved in a variety of physiological processes, including enzyme activation in photosynthesis and respiration and the maintenance of cellular osmotic potential in plants. Potassium is mobile within the grapevine, and due to the relatively high requirements in vineyards, it is often applied as a fertilizer. A strategic application of PeKacid 0-60-20 along with FertiFlow Potassium+ 8-0-47+7S ensures optimal potassium supply, which directly influences bunch size, shape, shine, and shelf life. Potassium plays a key role in regulating water balance, which is crucial for extending storage longevity. Additionally, sulfur in FertiFlow Potassium+ 8-0-47+7S enhances pungency and color, contributing to better market value. While SOP (0-0-50) is commonly used to meet potassium requirements, FertiFlow Potassium+ 8-0-47+7S offers a more balanced nitrogen-to-potassium ratio, ensuring improved nutrient uptake efficiency. Since potassium absorption is enhanced by nitrogen during maturity, this balanced approach leads to superior results over SOP alone.  Additionally, the use of Nutrivant Peakvant (0-49-32) enhances bunch firmness, quality, and overall yield. For better results, it is recommended to apply two foliar sprays of Nutrivant Peakvant @ 5 g/l at an interval of 10 days.

Conclusion:

There is no exception for the effect of climate changes on grape growing as many studies have indicated the adverse effects on agriculture particularly with respect to increased frequency of extreme events during summer, heat waves and erratic rainfall patterns. Looking over the changes in the climatic conditions over the past two decades, further change may shift in grape growing regions where it will be not easier to achieve desired quality parameters even with most popular variety of that region. The impact of climate change can be observed on both grape physiology and biochemistry. Hence, necessary adaptation strategies should be kept in mind to maintain grape yield and quality parameters. Hence, proper nutrition management to get quality berries and for achieving higher yields with increased bunch size and weight requires a balanced supply of essential nutrients like phosphorus, potassium, calcium, sulphur, boron, and zinc. These nutrients are critical for energy transfer, cell division, and overall storage quality. Proper nutrient and water management helps prevent issues like mummification or water berries and uneven development.

References

Anonymous, 2021, Agricultural and Processed Food Products Export Development Authority

(APEDA), Government of India. https://apeda.gov.in/.

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Klein, I., Strime, M., Fanberstein, L., Mani, Y. 2000. Irrigation and fertigation effects on phosphorus and potassium nutrition of wine grapes. Vitis. 39, 55–62.

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Romero, I., García-Escudero, E., Martín, I. 2010. Effects of leaf position on blade and petiole mineral nutrient concentration of Tempranillo grapevine (Vitis vinifera L.). Am. J. Enol. Viticult. 61: 544-550.