Effects of Growth Duration on Grain Yield and Quality in Rice (Oryza sativa L.)

Abstract

It is important to clear the relationships of growth duration with rice yield and quality in determining the breeding ob-jectives and cultivation strategies. In this paper, plants of japonica rice varieties Ning 111 and Chunjiang 302 with different growth durations resulted from short-day treatment were used to investigate the changes of yield and rice quality. The results showed that, the growth duration of more than 152 d had little effect on yield, but when less than 152 d, there was a significant positive correlation between growth duration and yield or dry matter accumulation; the smallest length and width of rice, as well as the lowest protein content and setback of amylum were observed in the treatments G2 or G3, which had moderate growth dura-tion of 131–132 d, the growth duration more than or less than 131–132 d would both increase the values of these rice quality indi-ces; amylose content also showed a similar trend, and the minimum value in two species all appeared in treatment G3 (132 d or 137 d), while for breakdown of amylum, the trend was just opposite. The percentage of chalky grains, chalkiness and gelatiniza-tion temperature in two varieties rose with shortening growth duration; the effects of growth duration on milling quality were gen-erally lower.