Performance evaluation of rice varieties under the System of Rice Intensification compared with the conventional transplanting system

Abstract

A field experiment was conducted at Deras Research Farm, Khurda district, Bhubaneswar, Orissa, India, to evaluate the performance of different rice varieties managed under System of Rice Intensification (SRI) compared with the current transplanting system (CTS). Five rice varieties were used for the study: (i)Khandagiri (early-duration, 90 days); (ii) Lalat (early-medium duration, 110 days); (iii) Surendra (late-medium duration, 130 days); (iv) Hybrid CRHR-7 (latemedium duration, 135 days); and (v) Savitri (long-duration, 145 days). It was seen that SRI practices significantly (p 5 0.05) improved the harvest index, percentage of effective tillers, panicle length, and various yield components in all the varieties. SRI hills having an open-canopy structure with higher leaf area index (LAI) resulted in greater light interception than the conventional transplanting methods.At the ripening stage, SRI plants had better root growth and a higher xylem exudation rate than CTS plants. This was associated with higher levels of chlorophyll in the lower leaves and a higher photosynthesis rate. Delayed senescence with enhanced photosynthesis in the lower leaves was also responsible for supplying more assimilates toward the roots for maintaining their higher activity. These features might also contribute to the improvement of grain filling and grain weight in SRI-grown plants as all the varieties performed better in terms of grain yield (12–42% higher) with this alternative management.