Weed Control in Dry Beans
April 15, 2003
Dept. of Crop and Weed Sciences
North Dakota State University
Three studies were conducted in 2002 field trials.
Dry bean response to flumioxazin
Pinto and navy dry bean injury from preemergence Valor has been consistently observed in NDSU research. The objective of this study was to safen other dry bean types by preplant incorporating Valor. Valor at 2 and 4 oz/A incorporated in to the soil injured and caused stand loss to the black, red, dark red kidney, and pink dry bean types. Injury did not decrease over time but the three indeterminate dry bean varieties (black, red, and pink) did produce high yield at harvest. Dark red kidney (bush-type) is determinate and yield was significantly lower possibly due to the determinate growth form.
Prowl, Outlook, Valor, and Prowl or Outlook plus Valor were preplant incorporated into soil near Hatton, ND. Dry bean and weed emergence was slow due to dry weather. No rain occurred until June 9. At 21 days after planting (DAP) dry beans were just emerging, but no eastern black nightshade had emerged. Injury at 28 DAP was stunting and poor emergence and better germination of dry bean and weeds was observed in the rototilled area of the plots than the rest of the field where just cultivation was used for field preparation. Slight stunting and no crop canopy was observed on June 27 (42 DAP) and July 9 (56 DAP). All rates and combination of Valor and Outlook applied alone completely controlled eastern black nightshade. Tank-mixes with Valor at 2 oz/A or higher caused significant injury.
Rezult tank-mixes in pinto dry bean
Treatments included soil-applied Prowl and Pursuit Plus applied alone or together followed by Rezult, or Rezult, Raptor, Reflex alone, or Rezult plus Raptor or Pursuit. The experiment was weed free. No herbicide treatment exhibited more than 4% dry bean injury at any evaluation except Pursuit Plus at 30 fl oz/A caused 25% injury at dry bean emergence but totally recovered at 14 and 21 days after treatment Any injury noted was slight puckering and crinkling of the newest trifoliate. No burn or speckling was observed. All treatments were safe to Pinto type dry bean.