Genotypic variation in peanut for transpiration response to vapor pressure deficit uri icon

abstract

  • Conservation of soil water resulting fromdecreases in stomata conductance under atmospherichigh vapor pressure defi cit (VPD) conditionsis a possible approach for enhancedtolerance of water defi cit by crops. Water defi citis usually a concern in peanut (Arachis hypogeaL.) since it is frequently grown on sandy soilswith low water-holding capacity. Seventeen peanutgenotypes were studied to determine theresponse of their transpiration rates (TR) to VPD.The results of this study demonstrated variationamong peanut genotypes with nine genotypesexhibiting a breakpoint in their VPD responseat about 2.2 kPa, above which there was littleor no further increase in TR. Therefore, thesegenotypes with a breakpoint have the possibilityof soil water conservation when VPD exceeded2.2 kPa. The remaining eight genotypes had a linearresponse in TR over the whole range of testedVPD. Also, the 17 genotypes could be separatedinto groups with differing rates of increasing TRat low VPD. The change in TR with increasingVPD may be important in determining the rate atwhich soil water is used under fi eld conditions

publication date

  • 2010
  • 2010