Flood tolerance and flood loss predictions for tepary bean across the US Southern Great Plains

Flooding can cause billions of dollars in crop losses per year. One method to combat susceptibility to flooding is through the identification and use of crops that withstand short flooding events. Tepary bean (Phaseolus acutifolius A. Gray) is an underused crop native to North America and currently grown in small amounts by the indigenous peoples of the Sonoran Desert of northern Mexico and southwestern United States. The genome of tepary bean is being used to improve heat, drought, and pest tolerances in common bean (Phaseolus vulgaris L.) through morpho-physiological changes to the shoots and roots. This study evaluated the effect of different flooding periods on biomass production and tissue C and N content of tepary bean compared with soybean [Glycine max (L.) Merr.]. The study also defined areas of Kansas and Oklahoma that may flood during periods of 1-3 d and potential effects on the two legumes. The analysis determined that for any 1 yr, 22% of Kansas cropland would flood during a 24-h period and 16% would flood during a 72-h (3-d) period. For Oklahoma, 30% of cropland would flood during a 24-h period and 25% would flood during a 72-h period. Although tepary bean withstands the abiotic stresses of high temperature and low precipitation, there was less evidence of flood tolerance. Overall, tepary bean genotypes survive 24-h flooding events, whereas 72-h events are detrimental to all traits evaluated. The highly erratic high intensity summer rainfalls common to the Southern Great Plains may reduce the ability of tepary bean to dependably produce biomass. Future breeding efforts should include developing flood tolerance in tepary bean to expand the region of use for this legume.