Seaweed extract of Ascophyllum nodosum (L.) Le Jolis on tomato yield and vegetative development

Abstract

Biofertilizers based on seaweed extract are a source of nutrients that can replace conventional synthetic fertilizers, allowing their use in organic agriculture. The objective of this research was to evaluate the effect of Ascophyllum nodosum (L.) Le Jolis seaweed extract on tomato (Lycopersicon esculentum) yield and vegetative development. The experiment was carried out under protected cultivation and in the field, using the Piccolo F1 cultivar. The experimental design was completely randomized in 5 × 2 × 5 factorial arrangement (five combinations of doses and frequency of seaweed extract application; two environments: greenhouse and field, with five assessment dates) for the variables: stem diameter, average number of leaves and relative chlorophyll content. For the other variables, a 5 × 2 factorial design was used (five combinations of doses and frequency of seaweed extract application; two environments); the following variables were evaluated: stem diameter, leaf relative chlorophyll content, number of leaves, average fruit weight, number of fruits, longitudinal and transverse fruit diameter, rachis length and average yield. It was possible to verify that the 0.3% seaweed extract dose under protected cultivation and in the field, applied every two weeks, increased the tomato yield, without altering the characteristics of fruits and vegetative growth.