Fator de resposta da produção (Ky) do milho safrinha para a região de Dourados, MS

Abstract

Plant productivity is directly and strongly by the amount of water that is made available for use, and even small deficits can significantly impact productivity. In this sense, the response factor of production (Ky) allows to evaluate the decrease in productivity due to the evapotranspiration that occurs, and therefore be used for crops forecast. Therefore, the present study aimed to determine the Ky for off-season maize crops in the region of Dourados, MS. In order to obtain the Ky, the linear regression model was used this requires data from real productivity (Yr) and maximum potential (Ym), as well real evapotranspiration (ETr) and maximum (ETm). Ym was assumed to 8820 kg ha-1 (147 sc ha-1), while Yr was obtained in each crop from the IBGE database. ETm and ETr were estimated by sequential daily water balance, considering four diferente sowing seasons (all in the off-season) and using their mean as final result. Yields were analyzed from 2001 to 2013. The off-season maize crops grown in the region of Dourados, MS, has been shown to have your productivity strongly related to water availability. Given the high value of Ky obtained (1.22), the off-season maize crops should be considered of high sensivity to water deficit, requiring irrigation for capacitive potential level and/or mitigate the effects of drought events due to lack of rainfall.