Relação entre coeficientes de cultura e graus-dia de desenvolvimento da alface

摘要: This research was carried out at the Campbell Farm of The University Arizona, from June 1994 to February 1995, with aim determining a growing-degree-days-based crop coefficient (Kc) equation for leaf lettuce (Lactuca sativa L.), using Fourier sine series model. Ten randomized experimental plots were irrigated, in order maintain soil matric potential greater or equal -20 kPa, as replications determination maximum evapotranspiration (ETm). Each plot consisted six raised beds, 7.3 m long and 1.0 wide, two rows L., cv. Waldmann's Green) thinned final population 48 plants per bed. thinning time occurred GDD 228oC average Kc 0.4. harvest 742oC 1.2. values function GDD, during season, allowed generation an that can be inserted into irrigation scheduling software, considering ending (adjustment GDD) 900oC.