Response of Lowbush Blueberry to Weed Control with Atrazine and Hexazinone

Atrazine at 4, 8, and 12 kg°ha −1 and hexazinone at 1, 2, 3, and 4 kg°ha −1 were tested in Nova Scotia at 9 and 13 locations, respectively. There was no indication that atrazine adversely affected lowbush blueberry ( Vaccinium angustifolium Ait). Hexazinone injury was observed at some locations at rates of 2 to 4 kg°ha −1 , and this injury was reflected in decreased yields. Atrazine and hexazinone treatments increased yields over all sites by 85% and 75%, respectively, although response varied widely among locations. Increased yields due to greatly improved weed control were related to increases in the number of flower buds per shoot and in the density of fruiting shoots. Chemical names used: 6-chloro- N -ethyl- N '-(1-methylethyl)-1,2,5-triazine-2,4-diamine (atrazine), and 3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1 H ,3 H )-dione (hexazinone).