FACTORES QUE INFLUYEN SOBRE LA GERMINACIÓN DE Ipomoea nil (L.) Roth

Abstract

Ipomoea nil is a weed that causes losses in the yield in different crops specially, especially soybean and cotton plant. Knowledge of the conditioning factors for it germination will permit an opportune and better control of the species. The effects of the scarification, temperature, pH, and osmotic potential on seed germination of I. nil were studied, with the objective of generating the information necessary to establish management strategies. The effects of different procedures of scarification were studied: sanding, incision and immersion in sulfuric acid. The germination of seeds submitted to different temperatures and photoperiods was evaluated. Ranges of pH between 4 and 9 with different osmotic potentials between –0.00 to –1.0 MPa were tested. The highest germination percentages were obtained with scarification via incision and exposure to acid for 60 minutes, with 99.00% and 92.70% germination, respectively. The optimum germination temperatures were 32 °C and 32/18 °C with germination values of 71% and 84%, respectively. In acids and neutral pH, the germination was positive. The maximum germination percentage was registered in the osmotic potential of –0.2 (92.67%) with the germination progressively decreasing until –0.8 MPa (51.33%). I. nil has a high germination capacity in environments with high thermo amplitudes, which is increased by mechanical and chemical scarification. The extreme conditions of alkalinity have a negative effect on its germination as do high osmotic potentials.