An herbicide that works in STRAWBERRY fruit production - Un herbicida que funciona en producción de FRUTILLA (FRESA)

Photo source: https://edis.ifas.ufl.edu

Hard seeded, broadleaf, winter annual weeds in strawberry plasticulture production in Florida emerge in the crop holes in the plastic mulch and reduce berry yield and quality. Clopyralid is registered for post-emergence control of broadleaf weeds but herbicide damage has been observed in commercial fields and preliminary observations suggest that effects vary with time of application. In order to address this issue Nathan S. Boyd and and Peter Dittmar with the University of Florida conducted an experiment in 2012/2013 and 2013/2014 to evaluate clopyralid rate (0, 140, 280 and 560 g ae ha-1) and application time on strawberry vegetative and reproductive growth. 
Clopyralid applications at 280 and 560 g ae ha-1 on January 2 and 16 in yr 1 reduced leaf number per plant by 33 to 44% and increased the number of deformed leaves per plant compared to the nontreated control. This pattern was not observed in yr 2. In yr 1 and 2, two times the label rate of clopyralid (560 g ae ha-1) tended to reduce the total number of floral buds compared to the nontreated control by 12 to 17%. None of the herbicide rates or application times reduced the number of flowers per plant, marketable berries per plant, yield over time, or total yield. They concluded that clopyralid applications at the rates and application times tested in this study may cause leaf damage, may reduce leaf number in some situations, but does not impact yield.
Source: Nathan S. Boyd and Peter Dittmar (2015) Impact of Application Time and Clopyralid Rate on Strawberry Growth and Yield. Weed Technology In-Press. http://www.wssajournals.org/doi/abs/10.1614/WT-D-15-00040.1