Canadian Forest Service Publications

Influence of droplet size and density on phytotoxicity of three herbicides. 1992. Prasad, R.P.; Cadogan, B.L. Weed Technology 6: 415-423.

Year: 1992

Issued by: Great Lakes Forestry Centre

Catalog ID: 3285

Language: English

Availability: PDF (request by e-mail)

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The effects of droplet size and numerical deposit density on herbicide efficacy differed among investigations that relied on commercial nozzles to produce droplets strictly within small, medium, or large sizes. A droplet generator capable of producing uniform and homogeneous droplets was therefore used in a greenhouse experiment. Four droplet size classes (150, 350, 450, and 650 micrometers) using glyphosate, hexazinone, and triclopyr on red alder, aspen, and white birch were studied. Herbicides applied in small (150 to 450 micrometers) droplets were more phytotoxic than large (660 micrometers) ones because of their greater numerical coverage and translocation. Leaf age, weed species, herbicide type, and mixture of droplet sizes were not critical in modifying the effects of droplet behavior; however, the concentrations of herbicide used had a positive effect. When the herbicides were applied at high concentrations, the influence of droplet size was nullified. These findings may help reduce the cost of application and the chemical burden in a forest environment.