Adaptabilidade e estabilidade de genótipos de arroz irrigado na fronteira oeste do Rio Grande do Sul

Abstract

The objective is to evaluate the adaptability and stability of rice genotypes at different times of sowing and years of cultivation, as well as identify the best genotypes and sowing dates that maximize performance gains. The experiment was conducted in a factorial 6 x 5, six dates of sowing and five rice genotype. Each sowing date presents a randomized block design with three replications. The plots with each genotype consisted of five lines spaced 0.17 meters from each other, with five meters long, with the floor area the three centerlines. The genotypes used were two conventional cultivars, Guri Inta CL, PUITA Inta CL, and three hybrids, Prime CL, CL QM 1010 and PC CL, the latter a precommercial hybrid. Cultural practices have always been carried out as required, using the proper management and recommended for culture. To evaluate the adaptability and stability we used the model proposed by Cruz, Torres & Vencovsky (1989) and to obtain the parameters we used the GENES statistical program. The most productive genotype in the general average of sowing dates was the pre-commercial hybrid, with 10.7 ton ha-¹ and the highest average of genotypes of grain production occurred on the date of 16/10/13, with overall average genotype 12.4 ton ha-¹. Adaptability and stability analysis indicated four favorable sowing dates and two unfavorable for rice yield. There were also differences in behavior between genotypes in favorable and unfavorable environments, showing the influence of sowing and year of production dates. Sowing in the second ten days of October showed higher productions and precommercial hybrid had higher prediction, stable performance and high grain production.