Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 1, 1996
Publication Date: N/A
Interpretive Summary: Some plants produce compounds that, when released into the environment affect the development of other plants. This is sometimes termed allelopathy. Kenaf is a crop that is incorporated into products that bring it into contact with the soil, and therefore into contact with other plants. Seed of cucumber, green bean, tomato, Italian ryegrass, and rough pigweed were placed in contact with various concentrations of extracts of kenaf tissue that were not weathered, or weathered up to 4 months. Germination and the length of hypocotyl and radicle were determined. Extracts of unweathered and weathered kenaf, especially at the highest concentration, reduced germination in pigweed, and to a lesser degree in tomato and ryegrass. As kenaf weathered, germination and length of most plants increased, suggesting that compounds affecting plant development were changing. Unweathered kenaf tissue or extracts may be employed in weed control. Weathered kenaf tissue or extracts may stimulate germinatio and post-germination development of beneficial crops.
Metabolites produced by one organism can have biological properties that affect development of other organisms. Kenaf is incorporated into products that put it in direct contact with other plants. This project was designed to determine if kenaf plant extracts affect germination and development of vegetable, grass and weed seed. Frost-killed kenaf was chipped and either immediately frozen (non-weathered) or applied to the soil in mats in December and allowed to weather for 2 or 4 months. Samples of non- weathered and weathered kenaf were ground and extracted with water. Various concentrations of the extracts were applied to the germination medium for seeds of cucumber, green bean, tomato, Italian ryegrass, and redroot pigweed. Distilled water was included as a control. Three concentrations of polyethylene glycol (PEG) were also included. Germination and hypocotyl and radicle length were determined. Extracts of non-weathered and weathered kenaf, especially at the highest concentration reduced germination in pigweed, and to a lesser degree in tomato and ryegrass. As kenaf weathered, germination and length of most plants increased. This suggests that detrimental compounds in tissues were leached or otherwise changed so that they had no effect or became beneficial. Osmolality had minimal effect on germination and post- germination development, indicating results were due to metabolites in kenaf. Incorporation of non-weathered kenaf, in soil or its extracts, may be employed for weed control. Weathered kenaf tissue, or extracts, may stimulate germination and post-germination development of beneficial crops.