Agronomic performance in radish fertilised with Calotropis procera (Ait.) R. Br. in two growing seasons

ABSTRACT Agronomic indicators were evaluated in radish fertilised with different amounts of biomass from Calotropis procera (Ait.) R. Br. (known locally as Flor-de-seda) incorporated into the soil at different times, and grown in two seasons (spring and autumn-winter), in the town of Serra Talhada, in the State of Pernambuco, Brazil. The experimental design was of randomised blocks, with the treatments arranged in a 4 x 4 factorial scheme with three replications, the first factor comprising the amounts of biomass of C. procera (5.4, 8.8, 12.2 and 15 6 t ha-1 on a dry basis) and the second, the times of incorporation (0, 10, 20 and 30 days before sowing the radish). The following characteristics were determined in the radish: plant height, number of leaves per plant, root diameter, fresh and dry tuberous root weight, and fresh commercial root weight. Maximum radish yield was obtained with 15.6 t ha-1 of C. procera biomass incorporated into the soil. The supply of nutrients from the green manure, and the period of maximum demand by the radish, were seen to be in sync for the incorporation time of 22 days before planting. Cultivation in the autumn-winter increased the radish cycle, providing greater commercial and total root yield.