Resumen de Thermal sum in the determination of the phenological stages of Chihuahua and Cuauhtémoc oats in Güémez Tamaulipas
Fernando Lucio Ruiz, Santiago Joaquín Cancino, Benigno Estrada Drouaillet, Andrés Gilberto Limas Martínez, Jonathan Raúl Garay Martínez, Yuridia Bautista Martínez
Objective: To determine the thermal sum requirements of Avena sativa (Cuauhtémoc and Chihuahua varieties) as Growing Degree Days (GDD) per phenological stage and their effect on the accumulation of total forage and the accumulation of each morphological component, in Güémez, Tamaulipas.
Design/Methodology/Approach: The mechanical sowing (120 kg ha1 seed dose) was carried out in 66 m plots with four replications of Cuauhtémoc and Chihuahua varieties. Subsequently, the plot was irrigated and fertilization works were carried out. The treatments consisted of two varieties and six phenological stages (Zadok’s scale: Z2, Z3, Z4, Z7, Z8, Z9) in a randomized complete block design.
Results: It was found that 1,923.5 and 1,831.5 GDD were obtained from November to March, respectively; these results are a crop requirement for the fulfillment of the biological cycle of the Chihuahua and Cuauhtémoc varieties. Yields by morphological component depended on the observed phenological stage. The highest leaf yield (P0.05) was obtained in stage Z3 (stem elongation): 2.7 t ha1 in Cuauhtémoc (accumulation: 1,032 GDD) and 3.6 t ha1 in Chihuahua (accumulation: 980 GDD).
Study Limitations/Implications: These results can only be applied to the evaluation area, as a result of the intervention of the environment on these physiological responses.
Findings/Conclusions: In Güémez, Tamaulipas, the Chihuahua oat variety requires 1,923.5 GDD to complete its biological cycle, while Cuauhtémoc requires 1,831.5 GDD. The difference between the thermal accumulation of the varieties and the phenological stages has an impact on the total forage yield and the yield of each morphological component.
