Abstract:

To study the efficacy of prometryn against 10 serious wheat weed species, the whole-plant bioassays was adopted to test the efficacy of prometryn against Beckmannia syzigachne, Alopecurus aequalis, Alopecurus japonicus, Alopecurus myosuroides, Lolium multiflorum, Pseudosclerochloa kengiana, Poa annua, Descurainia sophia, Galium spurium and Capsella bursa-pastoris. Prometryn of different doses were applied on each weed species at pre-emergence and early post-emergence (2-3-leaf for grasses and 2-whorl-leaf or 2-pair-leaf for broadleaf weed species). Thirty days after early post-emergence treatments with label dose of prometryn (750 g/hm ² active ingredient), the inhibition rate of the fresh weight of the aboveground parts of D. sophia, G. spurium and C. bursa-pastoris was 89.75%, 94.04% and 75.00%, respectively. As well, the early post-emergence treatment with 1/2 label dose of prometryn could inhibit 89.64% aboveground growth of D. sophia. Thirty days after early post-emergence treatment with label dose of prometryn could totally kill the seedlings of A. aequalis, A. japonicus and P. kengiana; and showed the inhibition rate of 95.80%, 83.58%, 82.77% and 60.11% against A. myosuroides, P. annua, B. syzigachne and L. multiflorum, respectively. Moreover, 30 days after pre-emergence treatment with label dose of prometryn could have >85% inhibition rate against A. aequalis, P. kengiana, P. annua and B. syzigachne. Therefore, early post-emergence applying of prometryn can be effective on controlling A. aequalis, A. japonicus, A. myosuroides, P. kengiana, P. annua, D. sophia and G. spurium, and constraining B. syzigachne and C. bursa-pastoris seedling growth, while shows low efficacy against L. multiflorum.

Key words: prometryn, wheat field, grassy weed, broadleaf weed, control efficacy