The novel ethylene antagonist, 3-cyclopropyl-1-enyl-propanoic acid sodium salt (CPAS), increases grain yield in wheat by delaying leaf senescence

The present report describes the effect of 3-cyclopropyl-1-enyl-propanoic acid sodium salt (CPAS-WO 2010/0822930), a novel water soluble ethylene antagonist, on senescence and grain yield of several cultivars of common wheat (Triticum aestivum L.) and durum wheat (T. durum Desf.). CPAS abolished ethylene-induced leaf and ear organ senescence, as evidenced by the inhibition of chlorophyll degradation. CPAS application to wheat plants grown under controlled (120 mg L^-1) or field conditions (110 mg L^-1) significantly increased grain yield in the range of 9-13 % and 3-45 %, respectively, depending on treatment and variety. The CPAS-induced increase in grain yield was usually more significant under extreme weather conditions. In some cases spraying once at the medium milk stage was sufficient to obtain the maximum increase in grain yield, while in other cases spraying twice at the medium and late milk stages yielded the highest increase. The above data support the common view, that there is a positive causal relationship between the delay of leaf and ear organ senescence and grain yield. The results of the present study demonstrate that CPAS can effectively be used to increase wheat grain yield, and possibly the yield of other field crops, under field conditions.