Tepary Bean: A Short Duration Summer Crop in Virginia*

INTRODUCTION Wheat farmers in Virginia and southeastern US could benefit greatly from the availability of a shortduration summer crop that could be produced during the period between wheat harvest in middle of June and before planting of the next wheat crop during October. Some wheat farmers plant soybean as a double crop system, but the productivity of double-cropped soybean is extremely low and variable. Tepary bean (Phaseolus acutifolius A. Gray, Fabaceae), a highly drought and heat tolerant plant that produces nutritious, high protein seed suitable for human consumption (Thomas et al. 1983; Nabhan, 1983; Scheerens et al. 1983; Miklas et al. 1994), may have special significance in Virginia and southeastern states to be used as a short-duration summer crop. Previous research with tepary bean, a native of southwestern US, has indicated that it can be successfully grown in Virginia as a short-duration summer crop (Bhardwaj et al. 2002). In this study, mean seed yields of 2239, 1899, and 1410 kg/ha, respectively were obtained from eight genotypes when planted during late May, mid June, or mid July during 1997 and 1998. However, information about seed composition or nutritional quality of Virginia-grown tepary bean is unknown. This information is needed to evaluate the overall potential of tepary bean as a short-duration summer crop in Virginia. Due to high drought tolerance, tepary bean could also have potential in many parts of the world where irrigation water is unavailable. Availability of fresh water is important for enhancing and sustaining agricultural production. Even though water covers about 70% of the Earth’s surface, only about 3% of the total quantity of water is classified as fresh water, and suitable for irrigation purposes. The rest of 97% of water has too high a salt content to be used for production of crop plants. Increasing world population is also reducing the amount of irrigation water. Given that the world population increased to more than 6 billion during the latter part of 1999 and is expected to be increasing, there is an urgent need for developing of drought tolerant crop plants. The objective of this research was to determine the composition of Virginia-produced seed of tepary bean and to compare its nutritional quality with that of other beans.