Modern horticulture poses the great challenge of satisfying a growing demand in terms of quantity and quality of fruit and vegetables. There are more and more consumers worldwide (7.9 billion people) and according to the latest UN forecasts, there will be more than 8.5 billion by 2025. In addition to quantity, market demand is also growing in terms of quality; we are becoming more and more demanding in terms of organoleptic characteristics (colour, smell, taste, nutritional value, etc.), absence of pesticide residues, etc.
In this context, biostimulation in horticulture (products of various origins;botanical, microbial, etc.) that act on the physiological and biochemical processes of plants through different routes, improving the vigour of the aerial part and root system, productivity, quality of harvests, effective protection against disease and physiopathologies, etc., are of vital importance. However, it is necessary to make a good choice and management of a biostimulant suitable for each phenological stage of the different crops:
Rooting and initiation of the crop:
It is essential to start biostimulation in horticulturre from the moment of transplanting. The seedlings have to withstand and overcome great stress as a consequence of adapting to the new conditions in the growing medium, from the environmental, edaphic, nutritional and pest and disease pressure point of view. In addition, the interaction of micro-organisms with the root system will bring innumerable benefits: they make available to the plant a greater quantity of essential macro- and microelements, they occupy a biological niche in the soil susceptible to nematodes, fungi and pathogenic bacteria creating competition for space and nutrients, and they provide, as a consequence of their metabolism, a large number of beneficial substances.
Vegetative development:
Once we have achieved a good implantation of the crop, it is essential to continue the biostimulation in horticulture in order to obtain adult plants with an adequate size and vigour, both in the aerial and root parts. It will be much easier for these crops to cope with all types of abiotic stress (climatic, osmotic, sanitary, nutritional, etc.) and to support the maximum number of fruits, as this will be the basis for the crop’s potential productivity and profitability.
Flowering, fruit set and fruit set:
In the agronomic management of horticultural crops, it is essential to promote the right conditions to reach an optimal balance between vegetative and generative growth of the plants, resulting indispensable the biostimulation in horticulture for metabolic processes related to the formation of floral organs fruit set and fruit set. We need a viable and functional flower from the reproductive point of view, which is the basis for building fruit with an adequate quantity and quality of seed (plant organs essential in the production of phytohormones and natural compounds necessary for the optimum development of quality fruit) and set on an aerial part with an adequate size and vigour to bring them to fruition.
Fattening and ripening:
The final processes of filling (fattening) and ripening are metabolic processes, which consume a large amount of energy and make fruits the main sink for plants. In addition, most horticultural crops have a continuous growth cycle, i.e. all processes occur simultaneously in one cultivar. Therefore, biostimulation in horticulture is essential.