Effect of Daminozide and Ethephon on Transplant Quality, Plant Growth and Development, and Yield of Processing Tomatoes1

Abstract

Abstract Treatment of tomato transplants (Lycopersicon esculentum Mill.) with (2-chloroethyl)phosphonic acid (ethephon) at 100 to 500 ppm when flower buds were visible but not open resulted in flower abscission of the first fruiting cluster, adventitious root formation on the plant stem, increased dry-matter content and more rapid plant recovery following transplanting than untreated and/or clipped plants. Fruit maturity was earlier and more uniform on treated than untreated plants. Treatment of transplants with ethephon at 0.28 kg per ha, combined with a fruit-ripening ethephon treatment at 0.9 kg per ha, increased ripe-fruit yield from a once-over harvest compared with untreated or either treatment alone. Flower abscission on transplants was erratic from treatment with 2,500 or 5,000 ppm of butanedioic acid mono-(2,2-dimethylhydrazide) (daminozide), dry matter was increased, no adventitious roots developed, and transplant recovery was similar to that observed with untreated and/or clipped plants. Daminozide treatment had no influence on fruit maturity and yield.