IPM UCONN Field Corn Row Spacing

EFFECT OF FIELD CORN ROW SPACING AND POPULATION ON WEED CONTROL

Studies have shown that filed corn will compete with weeds for light, water and nutrients. The relative competitive ability of field corn can be enhanced by increasing plant population. Herbicides are needed to control weeds primarily during the period before the corn leaf canopy closes. Faster canopy closure with higher plant populations will mean less herbicide than currently recommended. Recent studies in Maryland have indicated herbicides were cut 75 percent on no-till cornfields without sacrificing yields when the number of corn plants were doubled by narrowing the row spacing form 30 to 15 inches.

Three Connecticut studies were conducted comparing the effects of two corn planting populations (28,000 and 35,000) and two row spacings (30 and 15 inch) on weed control In general, total weed biomass was reduced when corn was planted in 15 inch rows compared to 30 inche row spacings. Higher corn plant populations reduced total weed biomass compared to the lower corn plant populations. Increasing corn plant populations and planting narrower corn rows should suppress weeds resulting in lower herbicide rates required for effective weed control.

Frank J. Himmelstein, UCONN Forage Crop Integrated Crop Management (ICM) Coordinator
and Robert J. Durgy, UCONN IPM Program Assistant

Reprinted from Integrated Pest Management Program 1996 Annual Report

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