ALLELOPATHY OF SHOWY RATTLEBOX DECOMPOSITION ON THE COMMON BEAN IN NO-TILL

Resumo

This study aimed to identify and quantify the phenolic compounds in soil covered with showy rattlebox (Crotalaria spectabilis Roth) at different decomposition times, followed by the sowing of common bean (Phaseolus vulgaris L.) and to determine the effects of these times on the emergence and initial growth of the subsequent crops. Common bean was sown at intervals of 0, 10, and 20days after the deposition of showy rattlebox biomass. Phenolic compounds in the soil were analyzed using ultra-performance liquid chromatography (UPLC). The evaluated parameters for common bean included emergence, emergence speed index (ESI), chlorophyll a and b, plant height, leaf area, and dry mass. Results showed that C. spectabilis decomposition increased the concentration of epicatechin and resveratrol in the soil, and catechin levels decreased. The showy rattlebox presence, independent of decomposition time, increased the plant height and dry mass of common bean. The shortest interval (0 days) between showy rattlebox biomass deposition and common bean sowing resulted in the highest rates of emergence, ESI, and chlorophyll a. Meanwhile, the common bean leaf area was greater when sown after 10 and 20 days of C. spectabilis decomposition.