PERFORMANCE OF AUS RICE VARIETIES WITH SUPPLEMENTAL IRRIGATION, FERTILIZER AND WEED MANAGEMENTS

Abstract

Field experiments were initiated in the month of April and ending in August through the year 2015 to 2017 at Sher-e-Bangla Agricultural University. In Experiment-I, twelve Aus rice varieties BR-3, BR-14, BR-16, BRRI dhan27, BRRI dhan42, BRRI dhan48, BRRI dhan55, BRRI dhan65, China (Muladi local), Kali Shait-ta (Muladi local), Benamuri (Muladi local) and Abdul Hye (Jhalkathi local) were tested under two irrigation regimes (with and without irrigation). Results showed significantly higher grain yield (4.22 t ha ii -1 ) under irrigated as compared to that of the non-irrigated one (3.90 t ha -1 ). Out of twelve, the local varieties yielded 27% lower (2.90-3.61 with an average of 3.26 t ha ) than the modern varieties (3.85-5.22, average 4.46 t ha -1 ). Experiment-II was conducted with two regimes of irrigation (with and without) and four varieties (BRRI dhan14, BRRI dhan48, BRRI dhan55 and BRRI dhan65) found outstanding in first experiment. Results revealed that the irrigated crop produced the higher grain yield (5.17 t ha -1 ), while the non-irrigated ones (4.44 t ha -1 ). Across the varieties, BRRI dhan14, BRRI dhan48 and BRRI dhan55 out yielded (4.95-5.30 t ha ). But the combined effect of varieties BRRI dhan14 and BRRI dhan48 with irrigation gave significantly higher grain yield (5.63 and 5.69 t ha -1 ). In the Experiment-III, three levels of fertilizer (recommended, 20% higher the recommended and 20% lower than recommended) and four varieties (BRRI dhan14, BRRI dhan48, BRRI dhan55 and BRRI dhan65) were tested. The recommended and higher dose contributed the significantly higher grain yield (5.23 and 4.95 t ha ). Among the varieties, BRRI dhan14, BRRI dhan48 and BRRI dhan55 yielded significantly higher (5.01-5.40 t ha -1 ). In Experiment-IV, four varieties (BRRI dhan14, BRRI dhan48, BRRI dhan55 and BRRI dhan65) were subjected to two weeding treatments (un-weeded and hand weeded) and results showed that the weeded crop had significantly higher grain yield (5.18 t ha -1 ) compared to the unweeded one (4.66 t ha -1 ). Under weeded condition, the variety BRRI dhan48 produced much higher grain yield (5.73 t ha -1 ) compared with those of other varieties. In the Experiment-V, BRRI dhan48 was grown under two irrigation regimes (with or without supplemental irrigation), two fertilizer doses (recommended and 20% higher the recommended) and three weeding methods (hand weeding, preemergence

herbicide and weeding by BRRI hand weeder). Combination of irrigation, recommended fertilizer and weeding by pre-emergence herbicide showed the highest grain yield (5.79 t ha -1 ) of the variety