Tuesday, June 19, 2007 - 8:20 AM
Douglas Firs (Boise Centre on the Grove)
323

The effect of Soil Salinity on Bean Dry Matter and Leaf Conductance

Abdelfettah Berrada, Colorado State University, Rocky Ford, CO, Mark A. Brick, Colorado State University, Fort Collins, CO, and Grant E. Cardon, Utah State University, Logan, UT.

A greenhouse study was conducted at the Arkansas Valley Research Center in 2006 and 2007 to determine the effects of increasing soil salinity on leaf stomatal conductance and dry matter of three dry bean (Phaseolus vulgaris L.) cultivars; Bill Z, UI911, and Sacramento. A local salt in 2006 and a combination of NaCl and CaCl2 in 2007 was added to each pot at the beginning of the experiment to reach target ECe values ranging from 1.5 to 11.0 dS/m. Bean plants were harvested at full bloom to early pod formation for dry matter (DM) accumulation, oven-dried at 65 oC, then weighed. Plant DM decreased significantly as the electrical conductivity of the saturated paste extract (ECe) increased. There was no significant salinity by bean cultivar interaction for DM in either year. Leaf conductance and transpiration were measured with the LI-COR LI-1600 Steady State Porometer three times during the plant growth period. Both leaf conductance and transpiration decreased significantly as ECe increased in 2006 and 2007. There was also a significant salinity by bean cultivar interaction in 2007, with Bill Z showing the biggest drop in leaf conductance and transpiration at ECe equal to or above 6.0 dS/m. Plant uptake of K, Ca, Mg, and Na generally increased as ECe increased.