Delayed Wilting of Tomato Plants by Chemical Closure of Stomata

Abstract

The growth retardants CCC and B-Nine, and the fungicides PMA and 8-HQ when sprayed to young tomato plants reduced the transpiration water loss by 20-35%, induced a reduction in stomatal width by 10-33% and delayed the wilting of plants due to soil drought by about a week. The order of effectiveness of these chemicals in inducing stomatal closure and in delaying the wilting of plants is: PMA>CCC>B-Nine>8-HQ. The significance and the mechanism of the chemical closure of stomata in relation to the survival of plants under conditions of soil drought is discussed.