Mechanical and chemical methods of weed control and their combinations on the yield and yield components of sweet corn (Zea mays L.) [Philippines].
1989
Kunjo E.M. | Manuel J.S.
A field trial was conducted at the Central Experimental Station (CES), College of Agriculture, University of the Philippines at Los Banos, College, Laguna from Oct to Dec 1987 to determine the effects of selected herbicides: atrazine, pendimethalin, and 2,4-D in controlling weeds in sweet corn, applied at different rates and in combination compared to mechanical methods, handweeded and weedy treatments. Major weed species in the experimental area were Rottboellia cochinchinensis (Lour.) W.D. Clayton, Cyperus rotundus L., Cleome rutidosperma D.L., Commelina benghalensis L., Amaranthus spinosus L., and Mimosa pudica L.R. cochinchinensis was the dominant species with a relative density of 62%. Pendimethalin gave better control of grasses especiallly R. cochinchinensis while control of broadleaves and sedges were effectively obtained with atrazine and 2,4-D, respectively. Pre-emergent application of atrazine in combination with pendimethalin both at 1.0 kg/ha followed by hilling-up 25 days after planting (DAP) was found most effective against major weeds. All treatments resulted in significantly lower population and dry weight of dominant weeds compared to weedy plots. Handweeded plot had the highest ear weight, 15.9 kg were obtained compared to the 5.9 kg from the unweeded check. Atrazine applied at 2.0 kg/ha increased yield by 33.75%. With pendimethalin at 1 kg/ha, a 42.5% increase was obtained. Handweeding was effective but had very high initial cost outlay. Atrazine applied at 2.0 kg/ha had the least cost and hence, the higher net income. Overall results confirmed that weed control is an indispensable operation in order to obtain good yield, and that the use of herbicides has a great potential especially in places where labor is scarce and costly.
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