Design of a hydroponic test to evaluate the biostimulant potential of new organic and organomineral products

Abstract

Currently, the use of biostimulants is increasing due to the need for greater productivity in agriculture. The European Union presented a new fertilizer regulation, UE 2019/1009, appearing for the first time the concept of biostimulants. Its main objective is to improve the efficiency of plants in the absorption and assimilation of nutrients or their tolerance to biotic or abiotic stresses, regardless of the nutrient content of the product. The objective of this work consisted in the development of a methodology to test in a short-term experiment the efficiency of commercial products as potential biostimulants in a crop of Capsicum annuum L. in strictly hydroponic conditions. Plants were irrigated with the respective product at the recommended dose in water, without the addition of other nutritional sources for 15 days. At the end of the test, the weights of the root and aerial part, the humidity, the chlorophyll indexes, and nutritional leaf content, as well as the volume and morphology of the roots and plants were obtained to evaluate the biostimulant effects on the plant growth and development. The water consumption was also evaluated to analyze whether any of the products generates greater water savings. The study concluded that the nutritive solutions with biostimulants produced a greater increase in the weight of the plant and a lower percentage of leaf moisture, as well as higher values of leaf chlorophyll. On the other hand, it was humic, fulvic, and algae biostimulants that presented the best values in terms of water savings. The methodology developed could be set to test in the short term the biostimulant potential of new products.