Influence of Vermicompost on the Concentration of Exogenous Indole-3-Acetic Acid and Its Effect on the Development of Tomato Plants (Lycopersicum esculentum L.)

Abstract

Indole-3-acetic acid (IAA) concentration is directly proportional to the amount of vermicompost (VC) added to sand substrates. The objectives of this work were to establish the effect of the amount of VC in sand substrates on the concentration of IAA and to determine its influence on tomato plants. Sand substrates with VC percentages (0, 20, 40, and 50%) were placed in pots; in each one, the concentration of IAA was determined at the beginning and the end (after supporting tomato plants), and its bacterial load was determined. In tomato plants, some vegetative and yield components were measured. The results show that by adding 1 kg of VC in a sand-based substrate, the concentration of exogenous IAA increases by 0.0470 and 0.0642 mg g−1 (at the beginning and the end, respectively). This increase was reflected in the development of the plants; for example, their roots demonstrated their maximum development (370.20 cm−3) when the amount of VC in the substrate was 3.95 kg. Therefore, the amount of VC used in the preparation of substrates influences the concentration of IAA in them, which is reflected in the development of tomato plants.