Abscisic acid-induced protection against diclofop-methyl injury in cultivated oat (Avena sativa L.): A dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Agricultural Science with Honours in the University of Canterbury

Abstract

The reduced efficacy of the selective herbicide diclofop-methyl (2-(4-(2,4-dichlorophenoxy)phenoxy] propionate) under drought conditions has been associated with the rise in endogenous abscisic acid (ABA).within the plant. To elucidate the physiological basis for this protection against diclofop-methyl injury, the mechanism of action for this herbicide was investigated initially. Cultivated oat (Avena sativa L. cv. Arouri) plants were established in a controlled environment chamber and were treated with a spray application of diclofop-methyl, (field equivalent rates of 0.5 and 1.0 kg a.i. ha⁻¹ ). The loss of electrolytes from leaf tissues was used as an index of the loss of membrane integrity and of diclofop-methyl injury.