The table grape can be a very complicated crop to cultivate, as it is susceptible to several biotic and abiotic factors. Typically, table grapes prefer climates with mild winters and dry summers, and sandy soils with a low concentration of sodium. Today, table grapes are mostly grown covered under plastic or under nets, which protect them from cracking, to which they are particularly vulnerable. Plant fertilization aims to ensure a fruit diameter of > 20 mm, sweetness, very good coloration, as well as resistance against damages during transportation to the markets. There are two types of grape fruit: "with seed" and "seedless". Additionally, they are differentiated by color: red, white-green and black. For this reason, it is essential to establish a balanced nutritional program to obtain fruits with the desirable size, containing a high dry matter, and high sugar content.
The correct fertilization and biostimulation of table grapes is the way to reach high goals in terms of quantity and quality. The yield of table grape cultivation depends significantly on sprouting, one of the stages with the highest nutrient demands.
The most important elements in this stage are zinc, boron and calcium without overlooking the ratio between nitrogen and potassium. Good post-harvest properties are achieved through an optimum supply of calcium, potassium and magnesium. A modern fertilization strategy for table grapes is based on two very important pillars: The controlled release form of nitrogen to avoid imbalances, with the integration of mineral and/or organic-mineral fertilizers. Biostimulation is also important, as it helps to support the plant’s needs at the most critical phenological phases, minimizing problems and improving quality and quantity. Therefore, it is suggested to apply NPK fertilizers with nitrification inhibitor technology or NPK with slow release fertilizers.
The most important element, nitrogen, should be applied also in the post-harvest stage in order to build up reserves for the next growing season. Potassium is an extremely important element for the bunch and the leaves; it should be applied in larger quantities during the first phases of vegetative growth or fractionated during the cycle.
Biostimulation is very important in three main stages: During the vegetative growth to improve the bud development and the production of new roots, before flowering to enhance good fruit setting and during the stage of veraison and maturation to achieve the highest results. Magnesium is another very important nutrient for the production of good quality table grapes, as well as silicium and calcium for the thickening of the skin, limiting cracking and reducing the negative impact of abiotic stress.
The biostimulation of table grapes begins with the correct fertilization of the soil, with complete fertigation programs with Hakaphos® and HydroSpeed® (or NovaTec® Solub). Basfoliar® Zn Flo and Basfoliar® Mg Flo are the most competitive alternatives to complement the fertilization, of course, in synergye with Basfoliar® Kelp SL.