Physiological characteristics of some rainfed upland rice cultivars

摘要

The pattern of variation in physiological parameters at different growth stages in seven improved upland rice cultivars was compared with traditional upland cultivar, Brown gora. LAI in general increased progressively upto flowering and declined thereafter. Prasanna had the maximum LAI. Dry matter accumulation increased upto 15 days after flowering (DAF) and Brown gora had the maximum dry matter. Aditya exhibited the highest LAD (63.3 days). It was maximum between 45 days after rice emergence (DARE)and flowering. CGR and RGR followed the similar trend of variation. Between 45 DARE and flowering, NAR varied from 53 to 148 mg dm~(-2) day~(-1). The improved cultivars had higher harvest index than Brown gora. Among the improved cultivars, semidwarfs had higher harvest index than tall cultivars. The extent and time of lodging could have affected harvest index 6f tall cultivars. Therefore, further improvement in straw strength is needed to achieve high yields in tall upland cultivars.