EFFECT OF ENDOTHALL AND GLYPHOSATE ON BLUEBERRY AND BARRENBERRY YIELD

Yields from a mixed blueberry (Vaccinium angustifolium Ait.)–barrenberry (Aronia melanocarpa (Michx.) Ell.) stand were taken 3 yr after treatment with endothall [7-oxabicyclo (2.2.1) heptane-2,3-dicarboxylic acid] followed by three rates of glyphosate [N-(phosphonomethyl)glycine]. Endothall alone or in combination with glyphosate had no effect on total yield of berries. The number and weight of blueberry fruit increased, and the number, weight and percent barrenberry in the mixed fruit decreased with increasing concentrations of glyphosate when preceded by endothall application. When the data were transformed to a frozen or canned grade basis, the number of barrenberry fruit showed a significant linear decline with an increase in herbicide rate, but remaining barrenberry fruit exceeded minimum U.S. Department of Agriculture grade requirements.