Chitosan doses and their effect on growth and yield of radish (Raphanus sativus L.) under greenhouse conditions

Abstract

Chitosan is a biopolymer with biostimulant activity in horticultural crops, although its effect depends on the applied concentration and plant species. The effect of increasing doses of chitosan on the growth and yield of radish (Raphanus sativus L.) was evaluated under greenhouse conditions. The experiment was conducted at the "La María" experimental farm, Technical State University of Quevedo, Mocache, Los Ríos, Ecuador. Three chitosan concentrations (1000, 1500, and 2500 mg L^-1) plus a distilled water control were tested in a randomized complete block design with five replications. Seedling roots were immersed for one hour in the corresponding solutions prior to transplanting. Morpho-agronomic variables related to vegetative growth and production were evaluated. Data were analyzed using analysis of variance and mean comparison with Tukey's test (p < 0.05). The 1000 mg L^-1 dose stimulated early vegetative growth, with higher values in plant length, leaf number, leaf length, and leaf width at 15 days after transplanting (DAT). The 1500 mg L^-1 dose produced the best productive response, with higher values in polar and equatorial root diameter, fresh weight, and yield (3885.18 kg ha^-1), equivalent to a 159 % increase over the control. It is concluded that chitosan at 1500 mg L^-1 represents a biostimulant alternative with agronomic potential to improve radish productivity under greenhouse conditions.