| dc.description.abstract | Commercial greenhouse vegetable transplant growers have several options available to control plant height but of those options, only one plant growth regulator,Sumagic (Uniconazole-P), is approved for use as a chemical option on tomato, pepper, eggplant, tomatillo, pepino, and ground cherry seedlings. It has been demonstrated in research that Sumagic is highly active in tomato and effective in retarding shoot elongation resulting in shorter more compact transplants but research has been limited to a few cultivars. In this study, twelve cultivars of tomatoes were chosen: three indeterminate, three determinate, and three container. Plants were sprayed with a one-time application of 2.5 ppm, 5 ppm, 7.5 ppm, and 10 ppm of Sumagic during the 2-4 leaf stage to evaluate height control. Results indicated all concentrations produced lower values than the control but no significant difference between concentrations for plant height, stem caliper, and plant dry weight. Greatest SPAD values were observed with the 10 ppm treatment. Flower response in 'Brandywine' to a single application of 0 ppm, 2.5 ppm, and 5 ppm of Sumagic demonstrated a greater number of flowers per plant at 5 ppm, while no significant difference was shown for number of flower clusters or number of flowers per cluster at other treatment levels. Using 2.5 ppm Sumagic will provide transplant growers the ability to modify plant growth in four different types of greenhouse grown tomato seedlings, in addition 5 ppm was shown to increase the number of flowers in 'Brandywine'. | |
