|Webber Iii, Charles
|TAYLOR, MERRITT - Oklahoma State University
|SHREFLER, JAMES - Oklahoma State University
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/5/2016
Publication Date: N/A
Technical Abstract: Allelopathy is the chemical interaction between plants, which may result in the inhibition of plant growth and development. Research was conducted to determine the impact of kenaf (Hibiscus cannabinus L.) plant extracts on the post-germination growth of five plant species. Four concentrations (0, 16.7, 33.3 and 66.7 g/L) of kenaf bark, core, and leaf extracts were applied to the germinated seeds of cucumber (Cucumis sativus L.), green bean (Phaseolus vulgaris L.), Italian ryegrass (Lolium multiflorum Lam.), redroot pigweed (Amaranthus retroflexus L.), and tomato (Solanum lycopersicum Mill.). The developing seedlings were measured 7 days after application to determine the length of their hypocotyls (mm) and radicles (mm), and the number of hair roots. Tomato, Italian ryegrass, and redroot pigweed followed similar negative responses to the extract source (kenaf bark, core, and leaves) and the impact of extract concentration, whereas, cucumber had a mixed response and green bean reacted positively to the kenaf extracts. Of the species tested, tomato was the most sensitive across all kenaf extracts and concentrations, resulting in decreased hypocotyl, radicle, and root growth. Green bean exhibited no negative effects Kenaf extracts produced no negative effects on green bean, but actually produced increased hypocotyl growth independent of the source of kenaf extract. Kenaf extracts resulted in a mixed response for cucumber. The kenaf bark and leaf extract decreased cucumber radicle growth, whereas, the bark and core extracts increased hypocotyl growth. Italian ryegrass hypocotyl growth decreased across all extract sources (bark, core, and leaf), while the kenaf leaf extract also reduced root growth. All kenaf extracts reduced redroot pigweed radicle growth, while the core and leaf extracts reduced hypocotyl growth. The research demonstrated that kenaf leaf extracts were the most allelopathic and hypocotyls were the most sensitive. Future research should isolate the chemicals responsible for both the negative and positive allelopathic impact on additional plant species, determine if the extracts will influence older plants, and pursue the use of these natural allelopathic extracts to benefit crop production and limit weed competition.