Response of Tomato to Pre-transplanting Applications of Chlormequat, Daminozide, and Ethephon1

Abstract Succinic acid-2,2-dimethylhydrazide (daminozide), (2-chloroethyl)trimethylammonium chloride (chlormequat), or (2-chloroethyi)phosphonic acid (ethephon) inhibited the growth of tomato ( Lycopersicon esculentum Mill.) plants for 2 weeks when applied at the 2-true leaf stage. All growth regulators inhibited leaf expansion but ethephon increased the number of new leaves initiated. Ethephon delayed flowering after the plants were transplanted into the field. Ethephon or chlormequat-treated plants produced yields similar to untreated plants. Daminozide at high rates increased yield due to a greater number of fruit per plant.