Efeito alelopático do extrato aquoso de folhas e caule de girassol sobre a germinação de milho e sorgo

The objective of this work was to evaluate the allelopathic effect exerted by aqueous extract of sunflower leaves and stem on corn and sorghum germination. Sunflower is an oilseed species that has important agronomic characteristics. Sunflower has an allelopathic effect on other plant species, inhibiting their growth. Stem and leaves were collected at UFSJ experimental field, Sete Lagoas campus. The test was performed on a Germitest Paper Roll, with 4 repetitions of 25 seeds of BRS - 1060 Hybrid (corn) and BRS - 506 (sorghum). The experimental design was completely randomized in a 2x5 factorial scheme, the mean results were submitted to Tukey test at 5% significance, processed by the SISVAR program. Aqueous extracts obtained from sunflower leaves negatively affected the vigor of corn seeds, observed by the first count test, however, there was no significant difference regarding the final germination of seeds submitted to extracts of sunflower leaves and stem in the different concentrations. For sorghum seeds, it was possible to verify that aqueous extracts of leaves at concentrations above 25% negatively affect seed germination and vigor.