才直紿礁君 2022,48(1):150- 157 Plant Protection re then performed to confirm its performance in the control of annual gramineous weeds and rice safety. The results revealed that the bioactivity of NCI to the seeds of E. crus-galli var. crus-galli was better than that of pretilachlor 30% EC (the control) at much lower dosage. As a pre-emergence herbicide at a dose of 30 g/hm2, the fresh weight inhibition rates of NCI 34. 5% SC against the susceptible and resistant annual gramineous weeds were all above 93. 26% ； the selectivity index (Z) of rice ranged from to , and it was safe to rice. At the - to -leaf stages of grass weeds, the fresh weight inhibition rates of 144 g/hm2 NCI to susceptible Echinochloa spp. were all above % after foliar spray treatment, but its effects to resistant Echinochloa spp., Leptochloa chinensis and Digitaria sanguinalis were slightly lower. It was safe for rice at the 1. 5- to 3. 5-leaf stage and there was no significant difference in fresh weight between 9-144 g/hirf NCI treatment and control. Field test results showed that, when NCI was treated with the dose of 60 and 75 g/hm2 as a pre-emergence herbicide, or by foliar spray treatment at the - to 2-leaf stage at the dose of 100 and 112
