Masters Theses


Soon Woon Toh

Date of Award


Degree Type


Degree Name

Master of Science


Plant, Soil and Environmental Sciences

Major Professor

David L. Coffey

Committee Members

Loenard M. Josephson, Vernon Reich


The effects of gibberellic acid (GA^). 1-Triacontanol (Triac) and Liquid of Ferment (OCB) were studied on snap beans (Phaseolus vulgaris cv. Early Gallatin), fieldcorn (Zea mays cv. T232xGT112) and tissues of cotton(Gosoypium arboreum cv. Nanking). A split-plot design was used in all experiments. Treatments were replicated three and four times in greenhouse and field experiments, respectively. Main plot treatments consisted of seed soak and foliar spray and sub-plot treatments consisted of growth regulator levels. Factors evaluated in snap beans were:yield, pod number and weight by sieve size distribution,plant height, width, fresh and dry weight. Factors evaluated on the field corn were: grain yield, leaf number, height of plant and top bearing node, standability, days to tasseling and silking. Fresh and dry weights of cotton calli were determined.Plant growth regulator rates of: 1) check, 2) OCB1:100, 3) OCB 1:500, A) OCB 1:1000 (v/v) and GA3 at 100 ppm were used in the first greenhouse and the two field experiments. Treatments used in the second greenhouse study were:1) check, 2) Triac Ig/ha, 3) Triac kg/ha, 4) Triac 16g/ha and OCB 1:100 (v/v). Plant yields were not significantly influenced by growth regulator treatments in any of the experiments. In the greenhouse studies, plant height, pod number in the 3-4 sieve size range and pod weight in the sieve size 2 range of snap beans were influenced by growth regulator treatments. In field studies on corn, plant height and height of top bearing mode were increased anddays to tasseling were decreased by growth regulator treatments. Only the fresh weights of cotton calli were significantly influenced by growth regulator treatments.

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