Growth, phytomass accumulation and yield of jack bean in different sowing dates

Abstract

Jack bean provides good soil cover, nitrogen biological fixation, reduction of erosive processes and weed infestation, allelopathic action and potential phytoremediation of contaminated soils. The objective of this study was to evaluate growth, phytomass production and jack bean yield in Santa Maria, Rio Grande do Sul, Brazil. Experiments were conducted in the 2011/12, 2012/13 and 2013/14 agricultural years, using a completely randomized experimental design with two, three and four sowing dates, respectively, for each agricultural year. The plants were collected at intervals of fifteen days in the first agricultural year, sampling the roots to a 0.20 m depth and the shoot, separating stem, leaves, inflorescences and legumes. The dry mass of roots, stem, leaves, inflorescences and legumes and total plant dry mass were determined. In the 2012/13 and 2013/14 agricultural years the plants were collected in certain phenological stages, evaluating shoot only. Plant height, leaf area index, number of grains per legume, average number of legumes per area, grain weight and yield were also determined. Jack bean showed rapid dry mass accumulation, being an alternative of intercropping between summer and winter crops in southern Brazil.