K.V. McCully1, M.J. Melanson1 and C. Morales1
(Partner: New Brunswick Wild Blueberry Growers Association)
Abstract: Two trials were conducted to evaluate hexazinone applications in the fruiting year of wild blueberries. Two hexazinone formulations, Velpar 75DF and Pronone 10G, along with an untreated control were evaluated at three application timings (early, mid, late) in a split plot randomized complete block design.Yields and visual ratings on weed control and crop injury were collected. Analysis of data collected from the two trials indicated that results were not always consistent between the two trials. This was attributed mainly to the differences in the trial sites. The first site located at Stewarton had a light weed pressure and had blight present, while the second site in Tracadie had a high weed pressure, and no blight present. By the final rating in the Stewarton trial all treatments except mid and late Pronone applications caused under 10% injury. In the Tracadie trial all the Pronone and Velpar timings provided under 5% injury. It appears that if a site is weedy, differences in formulation and timing is not as critical and evident as compared to a site with less weed pressure. Overall, the earlier the applications the less chance of blueberry injury. Later applications can be made safely in some instances but risk of crop injury is greater. Yield data was variable and difficult to relate back to visual crop injury or weed control. There was no clear relationship between injury observed, weed control, or blight with final yields for either trial. Poverty oatgrass control was considered excellent from Velpar/Pronone treatments applied at all 3 timings in both trials. It was more important that hexazinone be applied than at what time or formulation for poverty oatgrass control.
1Potato & Horticulture Branch, NBDARD, Fredericton, NB E3B 5H1