Weed Management in Sweet Corn
Weed competition trials with rows 25, 51 or 89 cm apart (with plants 30 cm apart in the row) demonstrated that in unweeded plots there was somewhat less yield loss in the narrower crop rows. Keeping the crop weed-free early, for 2, 3, 4 or 5 weeks was better than leaving the crop weedy for 5 weeks and weeding from then onwards.
Trials on inter-row cultivation with a row crop cultivator, a spider gang tool or a brush hoe did not provide adequate weed control in sweet corn, nor did flexi-tine harrowing. Cultivations must be shallow to avoid root damage. Flame weeding has given short-term weed control but could not maintain control of germinating weeds through the season. Others suggest corn can be flame weeded when it reaches a height of 4 inches and can be flamed until canopy closure. If flamed earlier than 4 inches tall the crop should not be treated again until it reaches a height of 6-8 inches. The crop row is flamed across with burners mounted in pairs, but staggered to avoid overlap, and set at an angle of 30 to 60 degrees from the horizontal. In addition to directed burners the use of leaf protectors reduces crop injury.
For further details download our outline on weed management in Miscellaneous Crops(64Kb pdf file).