In 2010, several sugarbeet fields had significant stand loss where Valor was applied to dry beans as a desiccant herbicide in 2009. In the fall of 2010, a desiccant herbicide trial was established at two locations.
One site had coarse soils, and the other site had a fine soils. Valor was applied at 2.0 ounces per acre and 4.0 ounces per acre (twice the normal rate to simulate overlap conditions), and Sharpen was applied at 2.0 fluid ounces per acre and 4.0 fluid ounces per acre (twice the normal rate to simulate overlap conditions) to soybeans (to simulate dry beans due to last year’s early harvest) on Aug. 27 and Sept. 21. Sugarbeets were planted on May 25, 2011, at the coarse-textured site and on May 26 at the fine-textured site.
On June 20, no sugarbeet stand loss was observed from any treatment applied last fall at the fine-textured site. However, on June 20, stand loss occurred with some of the treatments at the coarse-textured site. Valor applied at 2.0 ounces per acre on Aug. 27 and Sept. 21 caused 2% and 17% sugarbeet stand loss, respectively. Valor applied at 4.0 ounces per acre on Aug. 27 and Sept. 21 caused 30% and 40% stand loss, respectively. Sugarbeet stand loss ranged from 0 to 4% for Sharpen applied at all rates and times at the coarse-textured site.
Due to significant sugarbeet stand loss in several commercial fields in 2010, Valor should not be applied as a dry bean desiccant herbicide if sugarbeet will be planted in 2012. The coarser the soil texture and the shorter the time period from the Valor application to planting of sugarbeet, the greater the risk of stand loss. Sharpen appears to be a safer choice as a dry bean desiccant herbicide if sugarbeet will be planted in 2012; however, the research trial has not yet been harvested to know if any yield loss will occur from the Sharpen even though no stand loss occurred.
Stachler is an NDSU and University of Minnesota Extension agronomist and sugarbeet weed specialist. Contact him at Jeff.email@example.com.
RISK: A desiccant may speed dry bean harvest, but some products may carry over into sugarbeets and reduce stands next year.
This article published in the September, 2011 edition of DAKOTA FARMER.
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