Field performance of selected and landrace tepary bean varieties in diverse southwestern USA irrigated production environments

The desert Southwest is the oldest area of continuous crop production in the continental USA. Tepary beans (Phaseolus acutifolius A. Gray) were a part of the ancient, irrigated cropping systems, but they were nearly lost during the twentieth century. They are now the subject of heightened research and breeding activity. We wished to ascertain the field performance of varieties improved by selection within the region with those selected outside the region. In one study, the selected varieties were evaluated in two locations across two seasons, and in another, they were evaluated at three locations in the Rio Grande Valley, the principal agricultural production region in New Mexico. A collection of 21 tepary landraces was also examined at the same three locations in the Rio Grande River Valley of New Mexico. Both selected and landrace varieties demonstrated a production capacity above 2000 kg ha(-1) under irrigated conditions. Seed size (as determined by 100-seed weights) was also examined in the selected varieties. Two varieties (TARS Tep32 and CSU148) displayed seed size at the lower range of the small market class of common beans. The developmental phenology of the selected varieties was similar across two seasons. One selected variety, CSU148, also displayed a high level of resistance to powdery mildew during one season favorable for disease development. The other selected varieties exhibited intermediate host-resistance responses to infection.