Effect of cutting management on the forage production and quality of tepary bean (Phaseolus acutifolius A. Gray)

Tepary bean (Phaseolus acutifolius A. Gray) is an underutilized drought tolerant annual legume, originating from the Sonoran Desert, that may be a beneficial forage/hay for beef cattle in the Southern Great Plains of the US (SGP). The SGP has erratic rainfall and periods of intermittent drought exacerbated by high summer temperatures. In 2020 and 2021, a split-plot design was used to evaluate 13 genotypes of tepary bean and a forage soybean (control) at El Reno, OK, USA to compare production of plant biomass and forage nutritive value parameters under seven harvest regimes. Genotypes were used as the main plot and cutting management as the sub-plot. Biomass production of all tepary bean genotypes equaled that of soybean (p > 0.05), while several genotypes had superior forage nutritive value traits (p & LE; 0.05). Overall, a 15-cm cutting height and 30-day harvest interval produced the best overall product (average dry biomass of 5.8 Mg ha(-1) with average relative feed values (RFV) of 165). Although all harvest regimes reduced total seasonal biomass, forage nutritive value increased. However, the tradeoff between forage production and nutritive value may be unacceptable to most producers. Further agronomic and breeding research is needed to encourage producers to grow tepary bean as a forage/hay in the SGP.

Automated summary

From the 2020 and 2021 studies, it can be concluded that planting tepary bean according to specific harvest regimes can result in biomass production equal to soybean and superior forage nutritive value traits. However, increasing harvest frequency reduces biomass production but increases forage nutritive value. Further agronomic and breeding research is needed to encourage growing tepary bean as forage/hay in the Southern Great Plains.