The 2009 ASHS Annual Conference

Chile peppers are economically important crops in many southern states of the U.S.  Limited information is available on drought tolerance for chile peppers. As new cultivars are bred and commercialized each year, some may be more tolerant than others. The objective of this study was to investigate the drought tolerance of four representative commercial cultivars of chile peppers. Seeds of ‘AZ-20’, ‘Early Jalapeño’, ‘Joe Parker’, and ‘Sandia’ were germinated in 2.6-L plastic containers filled with sandy loam soil. Three dry-down cycles were applied by withholding irrigation until leaves were severely wilted.  The first dry-down was applied when seedlings had eight true leaves, the second cycle was applied 12 days after the first dry-down. Before terminating, plants in the drought treatment received a third dry-down. Plants in the control treatment were well irrigated throughout the experiment. Soil moisture contents were monitored using soil moisture sensors. Leaf conductance was measured daily during the dry-down cycles. The experiment was terminated when plants reached the flowering stage. Shoot, root and total dry weights were reduced by drought stress in ‘AZ-20’, ‘Joe Parker’, and ‘Sandia’ but not in ‘Early Jalapeño’. The ratio of root to shoot dry weight was not affected by drought stress, regardless of cultivar. Drought stress reduced leaf conductance of all cultivars but the relationship between the leaf conductance and soil moisture content differed among cultivars. Leaf conductance in ‘Early Jalapeño’ decreased more slowly as soil moisture content decreased compared to the other cultivars.