Penentuan Tempoh Kritikal Untuk Mengawal Rumpai dalam Kawasan Penanaman Padi Wangi MRQ 76, Q 88 dan Q 89

A study on critical period (CP) for weed control in fragrant rice MRQ 76, Q 88 and Q 89 was conducted in main season 2012/2013 and off season 2013 at MARDI Seberang Perai. The results showed that the CPs (based on 5% acceptable yield loss level (AYL)) for weed control of MRQ 76, Q 88 and Q 89 planted in main season were from 5 to 64, 13 to 68 and 8 to 66 DAS (Days after sowing), respectively. On the other hand, CPs of MRQ 76, Q 88 and Q 89 planted in off season were from 6 to 73, 9 to 81 and 3 to 83 DAS, respectively. If based on 10% AYL, CPs of MRQ76, Q 88 and Q 89 planted in main season were from 19 to 38, 28 to 41 and 14 to 53 DAS, respectively. CPs (based on 10% AYL) of MRQ76, Q 88 and Q 89 planted in off season were from 15 to 55, 19 to 68 and 10 to 66 DAS, respectively. The study clearly demonstrated that CPs of off season were longer than CPs of main season. The dry and hot climate in off season probably caused the slow growth of fragrant rice and eventually affected the competition ability of rice against the weeds.