The Effect of Ultraviolet Radiation and Di-1-p-Menthene on the Phytotoxicity of 2,4-D Applications to Black Valentine Bean Plants
Technical rept. for Oct 71-Sep 73,
EDGEWOOD ARSENAL ABERDEEN PROVING GROUND MD
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Studies were conducted to determine the relationships, if any, between ultraviolet light, plant growth, and plant response to di-1-para- menthene a dimer of beta-pinene, the dimethylamine salt of 2,4- dichlorophenoxyacetic acid, and the combination of the latter two. Greenhouse- grown bean plants Phaseolus vulgaris L. cv. Black Valentine were exposed for various time periods to a mid-ultraviolet light source having a major emission peak at 254 nm. The energy level recorded at plant height was 350 ergssq cm sec. Plants exposed to this light source for 1 hr had chlorotic, malformed leaves. Plants exposed for longer periods 2 hr had desiccated, discolored leaves, while plants exposed for 3 hr died. An exposure time of 15 min was used as the maximum safe dose for the subsequent studies in which the plants were exposed to the light source 30 min after application of the herbicide treatments. Irradiation of the plants treated with 2,4-D did not result in a significant reduction in herbicide efficacy. The addition of di-1-p-menthene to the spray solution caused significant increases in the phytotoxicity of the herbicide.
- Agronomy, Horticulture and Aquiculture
- Anatomy and Physiology