Integrated Crop Management

Herbicide drift problems must be resolved

This spring has been far from ideal with regard to herbicide applications. Temperatures have been near record lows and wind conditions have been near record highs. Although cool temperatures have slowed weed development and, therefore, extended the application window, herbicides have been applied in some of the worst wind conditions, and complaints about herbicide drift have been numerous. Just because there is a need to apply a herbicide treatment does not suggest that appropriate environmental stewardship can be ignored.

[1] Nozzle selection affects drift potential.

Chemical trespass, or herbicide drift, is one of the most important issues facing agriculture. Using current application methods, chemical drift is an inevitable component of pesticide application. The potential for drift can be minimized by increasing carrier volume, lowering the spray boom, using nozzles that create larger spray droplets, and reducing spray pressure. However, the best strategy to minimize spray drift is to avoid applications when wind conditions are high. While this strategy may seem simple, it is the most effective and consistent drift control practice. Because commercial applicators may not have much flexibility to modify application equipment, spraying when conditions minimize drift is their only effective means to avoid this problem.

The public is less willing to accept pesticide drift than in the past. Unless those in the agriculture industry recognize this and change accordingly, the likelihood of restrictions and regulations that could reduce the effectiveness and use of agricultural chemicals is inevitable. We must rethink applications and make adjustments to minimize pesticide drift. Growers must understand that commercial applicators are required to make safe and timely applications, and that applications occasionally will be delayed until conditions are less likely to result in spray drift.

This article originally appeared on pages 69-70 of the IC-478(10) -- May 26, 1997 issue.


Source URL:
http://www.ipm.iastate.edu/ipm/icm//ipm/icm/1997/5-26-1997/herbdrift.html