Summary Stability analysis tor yield, phytomass and harvest index (HI) was carried out for 75 cultures belonging to flowering duration ranging from 85 to 125 days representing early, medium and late duration groups in rice. Among the early materials (UVT 2), IET 3629 showed higher yield with higher stability mainly due to its trend in phytomass rather than its HI which showed moderate stability. But in IET 3116 the pattern of HI was reflected in yield despite higher production and stability in phytomass. Again, IET 4163 among UVT 4 and IET 5656 and Pankaj among UVT 5 materials showed the trends of phytomass accumulation and stability in their respective yields independent on variations in HI. Hence, it may be concluded that improving the degree of stability in HI is more vital for further tncreace in yield potential.
