a comparison of herbigation and conventional method of eradicane (eptc+dichloroacetamide) application in controlling weeds in corn crop

to investigate the efficiency of eradicane application, using herbigation as compared with conventional method (spraying), concerning weed biomass and density reduction and change in corn grain yield, a factorial experiment was conducted based on randomized complete block design in 2006 at research fields of university of tehran (karaj). eradicane was applied at 4.5 (labeled rate), 3.15 or 5.85 kg ai/ha while applying four application methods, namely: conventional spraying, herbigation via the first irrigation, herbigation via the second irrigation and applying eradicane through both the first and second irrigations each at half a dose of a single application rate. weed infested, weed free and atrazine plus alachlor (at labeled rate, 0.8+2.4 kg ai/ha) were also included as controls. the results showed the least weed density at early growth season observed with conventional spraying method. however, at physiological maturity stage, there was no significant difference between conventional spraying and herbigation (via the second irrigation). both conventional spraying and herbigation (via the second irrigation) had the same efficacy in reducing weed biomass at season-long. herbigation via the first irrigation did not provide an acceptable weed control, since the highest weed biomass and density accompanied this treatment. maximum corn grain yield was obtained with conventional spraying, however, it did not differ from herbigation via the second irrigation. eradicane applied at either rates of 4.5 or 5.85 kg ai/ha resulted in the highest corn grain yields along with the least weed biomass or density. no eradicane treatment yielded as much grain as atrazine plus alacholr, because of not being as effective in controlling weeds. however, if farmers are about to apply eradicane through furrow irrigation, a herbigation via the second irrigation at a maximum rate of 5.85 kg ai/ha could be recommended.