Decreasing Transpiration of Field Plants by Chemical Closure of Stomata

Abstract

CHEMICALS which close stomata have been described by Zelitch¹. When sprayed on leaf surfaces, the compounds decrease transpiration and photosynthesis of detached leaves² and of maize plants in soil³ by increasing the diffusion resistance of stomata. When sprayed on intact tobacco plants in the greenhouse² or on sunflowers growing in bins of soil outdoors³, the compounds reduced the loss of water from the soil. It remained to demonstrate the effect of chemical closure of stomata on transpiration by a population of plants in the field.