Yield s'i'ability of oat grain: effect of the use of fungicides

Abstract

Twenty oat (Avena sativa L.) genotypes were evaluated for grain yield stability and the effect of fungicide application on the genotype x environment (GxE) interaction in four locations in southern Brazil during 1986, 1987 and 1988. Eberhart & Russell's (1966) parameters (, and Sd) were adopted and analyses were performed according to three models: with fungicide application, without fungicide application, and, complete model. Results indicated a strong GxE interaction, although no genotype showed stable grain yield performance, as shown by the high regression deviations observed. Fungicide application caused an increase in mean grain yield performance, but did not affect the GxE, interaction. UPF 7 and UFRGS 7 appear to be good genotypes for southern Brazil because they are productive and insensitive to environmental changes; on the other hand, UPF 6 and UFRGS 10 could be more useful for farmers, since they respond positively to the environmental improvements.