Relative efficiency of herbicides in maize + cowpea intercropping system for green fodder.

摘要

The effects of atrazine (1.0 kg/ha), pendimethalin (1.0 kg/ha), alachlor (1.0 kg/ha), metolachlor (1.0 kg/ha), butachlor (1.0 kg/ha), oxyfluorfen (0.1 kg/ha), fluchloralin (1.0 kg/ha), and hand weeding or intercultivation at 20 days after sowing (DAS) on weed density and on the yield of maize (cv. APFM-2) + cowpea (cv. EC-4216) intercropping system were studied in Rajendranagar, Hyderabad, Andhra Pradesh, India, during the kharif of 2000. Atrazine effectively controlled the grass weeds Cynodon dactylon and Digitaria sanguinalis, and the broadleaved weeds Celosia argentea, Cleome viscosa, Commelina benghalensis, Parthenium hysterophorus, Phyllanthus niruri and Tridax procumbens during the first 40 days, but was the least effective against Cyperus rotundus. Atrazine and oxyfluorfen inhibited the sprouting of P. hysterophorus until harvest. Metolachlor and alachlor were highly effective in the reduction of the total weed density (43 and 76/m2). The herbicides were more effective than manual weeding and intercultivation in the enhancement of maize yield. Plants in plots treated with atrazine died a few days after sowing. Oxyfluorfen was also phytotoxic on cowpea, and more than 1/3 of the plants died within 10 days. Metolachlor resulted in the highest cowpea yield (14.9 t/ha), total yield (32.6 t/ha) and total crude protein yield (1065 kg/ha). The effects of pendimethalin, fluchloralin and butachlor were similar to those of intercultivation and hand weeding..