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Abstract

Multi-environment testing helps to identify stable genotypes. The objective of this study was to evaluate Chinese hybrid rice varieties for their grain yield and yield stability at different environments. The multilocation rice evaluation trials were conducted during summer seasons of 2017 and 2018 at five different environments, namely, Hardinath (Dhanusha), Kabre (Dolakha), Parwanipur (Bara), Khumaltar (Lalitpur) and Dhakaltar (Tanahun) in Nepal. Four hybrid rice varieties namely LPNBR1618, LPNBR1615, LPNBR1628 and LPNBR1632 (Standard check variety) were evaluated in a randomized complete block design with four replications in each location. The results indicated a significant (p<0.05) variation in grain yield among the genotypes at Hardinath, Khumaltar, and Kabre whereas they were non-significant for grain yield at Dhakaltar and Parwanipur. The combined analysis of variance indicated significant (p<0.05) effects of environment and genotype × environment (G x E) interactions on grain yield. The pooled data over locations and years showed that LPNBR1632 produced the highest grain yield (7.5 tons/ ha) followed by LPNBR 1618 (6.3 tons/ ha) in terai region (Hardinath and Parwanipur). Similarly, LPNBR1618 gave the highest grain yield (10.3 tons/ ha) followed by LPNBR1615 (9.5 tons/ ha) in mid hills region (Kabre, Khumaltar and Lumle). The genotypes LPNBR1615 (b=1.13), LPNBR1618 (b=1.19) and LPNBR1628 (b=1.15) had more than unity regression indicating the genotype’s suitability towards favorable environments. GGE biplot showed genotype LPNBR1615 was stable genotype among all genotypes. This study suggests that LPNBR 1615 can be grown for higher grain yield production in terai and mid hills of Nepal.

Keywords: Multi-environments, Genotype stability, Rice hybrid varieties