Substâncias húmicas como promotoras do crescimento e composição nutricional radicular em pimentão

Abstract

The bell pepper (Capsicum annuum L.) is a plant of nutritional and economic importance for human beings, however, it is still not widely cultivated in the semi-arid region of Paraíba. Recent studies have shown that the use of humic substances as biostimulants can promote an increase in plant growth, enhancing the absorption and assimilation of nutrients, resulting in increased production. Given this, the objective was to evaluate the biostimulant capacity of humic substances in association with cattle manure in promoting plant growth in the cultivation of organic bell peppers in the semi-arid region of Paraíba. The research was carried out at the family farm company: Canteiro Cheiro Verde, located in the municipality of Nova Floresta. The experimental design consists of 12 treatments, in a randomized block design, arranged in a factorial scheme with 4 doses of manure (8, 18, 28 and 38 t ha-1) and 3 doses of humic substances (0, 8 and 12 kg ha 1). The analyzed variables were plant height, stem diameter, leaf length, leaf width, leaf area, root growth, root dry mass, relative growth rate of plant height, relative growth rate of leaf area and relative growth rate of stem diameter, root nutritional contents of nitrogen, phosphorus and potassium. Humic substances in interaction with cattle manure provided a 36.05% increase in root nitrogen content. The root potassium content had an increase of 10.62%. The increases obtained in plant height, leaf area and root dry biomass were 21.2%, 58.21% and 8%, respectively. The largest stem diameter (18.98 mm) and the greatest total root growth (22.45 cm) were obtained by applying 26.55 and 8 (t ha-1) of cattle manure, respectively. The association of humic substances with cattle manure promoted positive growth of the aerial part, root dry biomass, and root nutritional enhancement in bell peppers under the edaphoclimatic conditions of the semi-arid region of Paraíba.