Biological preparations from crop waste for organic farming

Abstract

Organic farming, aimed at cultivation of crops without the use of artificial fertilizers, is an important trend in the development of agricultural economy. The primary role in organic farming is assigned to substances of natural origin, so-called biostimulants and bioprotectors, which improve plant growth and yield without negative impact on the agroecosystem. In this work, extracts from potato (Solanum tuberosum) and tomato (Solanum lycopercicum) haulm were studied for possible use as biological preparations in organic farming. Ultrasonic treatment from 10 to 50 minutes was applied for productive extraction of extractive substances from potato and tomato haulm. Bacteriostatic activity tests showed that potato leaf extracts selectively acted on Pseudomonas sp. (strain 2), Bacillus subtilis strain 26D and Pseudomonas fluorescens strain B4050, which allows us to recommend them for use as bioprotectants. Antioxidant activity (AOA) in extracts from tomato stems and leaves, which were tested for seed germination and tomato seedling growth in comparison with commercial biological preparations, was evaluated using potentiometry method. Tomato leaf extract showed the highest effect, surpassing the effect of commercial preparations. It was observed that there is a correlation between the growth-stimulating effect of tomato stem and leaf extracts and their AOA. The high AOA and absence of inhibitory or phytopathogenic properties of tomato leaf extract allows us to consider it as a possible ingredient for the creation of a new biostimulant.