Yield improvement by antitranspirant application in droughted wheat is associated with reduced endogenous abscisic acid concentration

Drought stress reduces seed crop yields in part by causing reproductive sterility associated with increased endogenous ABA. Application of the film antitranspirant, di-1-p-menthene, during reproductive-stage drought has been shown to ameliorate yield loss wheat but physiological processes involved are not understood. Using rain shelters simulate Mediterranean-type terminal drought, we studied possibility that application antitranspirant both ABA concentration and subsequent loss. Di-1-p-menthene was sprayed on droughted spring plants (cv, Chilham) at 1.0 L/ha two separate field experiments, three growth stages between stem elongation spike emergence 2018; four anthesis 2019, unsprayed serving as control. decreased yield. reduced 33% 40%; improved grain 16% 15% averaged across all 2018 respectively. The consistent effects di-1-p-menthene years suggests mechanism amelioration is related key stages.