|CHAVES-CORDOBA, BERNARDO - Washington State University|
|KHOT, LAV - Washington State University|
|Miklas, Phillip - Phil|
Submitted to: Soil and Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/22/2018
Publication Date: 3/20/2018
Citation: Boydston, R.A., Porter, L.D., Chaves-Cordoba, B., Khot, L., Miklas, P.N. 2018. The impact of tillage on pinto bean cultivar response to drought induced by deficit irrigation. Soil and Tillage Research. 180:63-72. https://doi.org/10.1016/j.still.2018.02.011.
Interpretive Summary: Dry bean yield suffers from drought stress and drought tolerant cultivars are a focus of breeding programs. Reducing tillage in row crops has advantages of conserving soil moisture and may alter the response of dry bean cultivars to drought stress. The response of eight pinto bean cultivars to drought stress when grown under conventional vs strip tillage was measured. Drought stress imposed at one month after emergence reduced bean seed yields 48 and 46% in 2015 and 2016, respectively. Strip tillage improved bean populations both years and moderated the decline in soil water, particularly in the upper 0 to 15 cm of the soil profile when water stressed. Bean canopy development and shading were generally greater with strip tillage than conventional tillage and strip tillage increased bean seed yield 9% in one of two years. Pinto bean growth and yield responses to strip tillage were generally either favorable or neutral when compared to conventional tillage demonstrating that strip tillage is a viable alternative for dry bean production under both favorable and limited water conditions.
Technical Abstract: Drought stress is a major factor limiting yield of dry bean (Phaseolus vulgaris) and drought tolerant cultivars are being developed. Reducing tillage in row crops has advantages of conserving moisture and increasing water infiltration, and may alter the response of dry bean cultivars to drought stress. The goal of this study was to evaluate the response of eight pinto bean cultivars to deficit irrigation when grown under conventional (CT) vs strip tillage (ST). Drought was imposed on half of the plots approximately 30 days after emergence by reducing irrigation by 48% [deficit irrigation (DI)] compared to full replacement of estimated evapotranspiration (FI = full irrigation). DI reduced bean seed yields 48 and 46% in 2015 and 2016, respectively. Dry bean cultivars varied in their response to drought stress by year. ST improved bean stands both years and moderated the decline in soil water, particularly in the upper 0 to 15 cm of the soil profile under DI when compared to CT. Mid-season shoot length, top biomass, leaf area index, and canopy cover were generally greater, and light transmittance through the plant canopy lower in ST compared to CT. ST increased bean seed yield 9% in one of two years over CT. ST improvements in crop stand, shoot and canopy development, and seed yield were consistent across irrigation levels and cultivars. Pinto bean growth and yield responses to ST were generally either favorable or neutral when compared to CT suggesting that implementing ST could benefit dry bean performance under both favorable and limited water conditions.