A search for metribuzin tolerance in fieldbeans (Phaseolus vulgaris)

Fieldbean, Phaseolus vulgaris L.; seed from 217 cultivars or lines were obtained from the regional dry bean nursery, Scottsbluff, NE and the Centro Internacional De Agricultura Tropical (CIAT), Cali, Colombia South America. Cultivars were screened in the field for differential tolerance to chlorsulfuron, 2-chloro-N- ( ((4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino) carbonyl) benzenesulfonamide; glyphosate, N-(phosphonomethyl)glycine; and metribuzin, 4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one. Differential cultivar tolerance was greatest in the metribuzin screening, and consequently future studies were limited to fieldbean tolerance to metribuzin.;A tolerant (XP-B146) and susceptible (D78157) cultivar were selected following the initial field screening and subsequent testing in nutrient solution. When these two cultivars were grown under field conditions the following year, no differential response to metribuzin was observed. Additional studies cast doubt upon the initial field screening, and the use of nutrient solution to accurately screen for metribuzin tolerance in fieldbeans. Selected cultivars did not grow similarly in soil and nutrient solution and this discrepancy in growth seemed to effect their response to metribuzin.;The response of parents, F...