Application of boric acid doses in association with tannery sludge in the early development of black pepper

Resumo

Information on the effects of boron and tannery sludge application on the growth and development of black pepper is insufficient to support the recommendations of these inputs for the crop. The present experiment estab­lishes adequate doses of boric acid in combination with the application of industrial waste from leather processing plants for the development of the black pepper cultivar ‘Bragantina’. We conducted the experiment in a green­house at IFES - Itapina Campus, Colatina city, Espírito Santo State, Brazil. For that, we used B horizon samples of a Red-   -Yellow Argisol as substrate. The experimental design was completely randomized in a factorial scheme with four replicates. Treatments consisted of three boric acid doses (0; 2; 4 mg dm^-3) in association with three tannery sludge doses (0; 0.125; 0.250 dm³ dm^-3) up to the vessel volume (18 dm^-3), with 14 sampling times. We assessed the following variables: vegetative plant growth; symptoms of boron deficiency and/or toxicity; soil pH; boron content. Soil application of boric acid showed considerable results in the early development of black pepper plants; the dose with the best response was 2 mg dm^-3. Using tannery sludge doses of 0.125 and 0.250 dm³ dm^-3 in the substrate was lethal for black pepper.