Abstract
In order to determine if herbicide efficacy is affected by nitrogen fertilizer, the influence of different nitrogen fertilizers applied in different combinations with hexazinone formulations were evaluated on herbaceous weed communities. Field studies comparing three application methods in conifer plantations showed greatest reduction in total weed cover with a co-granular formulation of hexazinone and triamino-s-triazine. Slightly less control was achieved with separate applications of liquid hexazinone and triamino-s-triazine granules, and poorest control with granular urea followed by liquid hexazinone. Weed control increased with an increase in hexazinone rate. Statistical analysis of the effect on conifers showed that the highest hexazinone rate significantly increased survival of noble fir (Abies procera Rehd.) and stem diameter of both noble fir and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and that the highest nitrogen rate significantly decreased survival of both species but did not affect stem diameter. Survival of noble fir and diameter of both noble fir and Douglas-fir were significantly increased where a co-granular formulation of hexazinone and triamino-s-triazine granules was used.
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White, D.E., Witherspoon-Joos, L. & Newton, M. Herbaceous weed control in conifer plantations with hexazinone and nitrogen formulations. New Forest 4, 97–105 (1990). https://doi.org/10.1007/BF00119003
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DOI: https://doi.org/10.1007/BF00119003