2008 Joint Annual Meeting (5-9 Oct. 2008): Assessment of Drought Tolerance in Dry Bean Varieties Under Both Dryland and Irrigated Conditions In The Northern Plains.

As in many other crops, one of the main limitations of dry bean (Phaseolus vulgaris L.) production is water availability. In North Dakota for example, drought tolerance is becoming more important because dry bean production is being slowly pushed from the fertile, non-irrigated Red River valley located in the eastern part of the state, towards the central and western regions of the state, where drought stress frequently occurs. Most commercial varieties are showing low tolerance to these harsher environments. Even more, there are not many studies of drought tolerance of dry bean for this region. Over the past two decades, dry bean variety trials have been conducted at the Carrington Research Station under both dryland and irrigated conditions. This is a great opportunity to obtain a preliminary assessment of how different varieties and market classes perform under drought conditions based on historical data across several years. The main objective of this study was to assess the differences in yield and other agronomic traits such as maturity, seed weight and test weight of dry beans cultivars grown under drought stress and non stress environments. The second objective was to estimate the genetic gain and progress over time due to the use of new varieties. Across years, data shows that dry beans grown under water stress conditions produced over 50% less seed yield than those grown under non stress conditions. These differences are more dramatic if individual market classes are analyzed. Seed yield in black bean varieties can be reduced as much as 31% in dryland compared with irrigated conditions. The following market classes are navy and pinto beans with 25 and 27% of yield reduction respectively, compared with the same cultivars grown under no water stress. These results will help to design strategic plans towards the genetic improvement of drought tolerance in dry beans for the region.