COMPARISON OF FOUR MANAGEMENT PROGRAMS FOR CONTROL OF ESTABLISHED PERENNIAL WEEDS IN BLUEBERRY

Four two-year weed management programs were designed to test the ability of organic and conventional herbicides combined with mechanical weed control strategies to control established perennial weeds in highbush blueberry (Vaccinium corymbosum). Two iterations of the trial were conducted near Mount Vernon, Washington, USA: ‘Elliott’ was used in the first iteration (2003-04), ‘Nelson’ in the second (2004-05). The four management programs were (1) organic, (2) low herbicide input, (3) high herbicide input, and (4) a combination of practices.
There were no significant differences in blueberry yield or fruit size between programs for ‘Elliott’ during either year or for the two-year average yield parameters, although there was a trend for increased herbicide inputs to produce more and larger fruit. ‘Nelson’ yield was also similar between programs within a given year, but the two-year yield average for the low herbicide program was twice that from the high herbicide program.
This apparent crop injury resulting from the high herbicide program was probably due to relatively young age of these bushes.
Perennial weed cover was reduced in practically all programs after two years.
Canada thistle (Cirsium arvense) control appeared to be most consistent with postemergence (POST) glyphosate and clopyralid followed by preemergence (PRE) diclobenil during dormancy.
Field horsetail (Equisetum arvense) control was excellent with dormant-season diclobenil, although multiple defoliations from flame, hand hoeing, and POST pine oil gave good results in one of the two iterations of this trial.

X International Symposium on Vaccinium and Other Superfruits

T.W. Miller, C.R. Libbey, B.G. Maupin

Vaccinium corymbosum, diuron, diclobenil, clopyralid, pine oil, propane flame, Cirsium arvense, Equisetum arvense

https://doi.org/10.17660/ActaHortic.2014.1017.15