Author
 |
Kremer, Robert |
|
Submitted to: International Symposium on Biological Control of Weeds
Publication Type: Proceedings Publication Acceptance Date: 7/9/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Important roles for biotic agents in integrated weed management include preventing seed production and weed emergence. Seed-attacking microorganisms described for a limited number of important weeds serve as examples of the potential for reducing weed seed production. Innundative releases of seed-feeding insects have successfully reduced seed production of specific weeds, subsequently reducing viable weed seeds in soils. Seed attacked by either microorganisms or insects can be detrimentally affected in soil resulting in reduced weed seedling emergence in following seasons. Combinations of different biotic agents may enhance efficacy of weed management over that with either agent alone. For example, a selective seed-feeding insect, Niesthrea louisianica, combined with seed-attacking fungi significantly decreased velvetleaf seed viability and seedling emergence compared to either insects or fungi alone. Insect-attacked, fungal-infected velvetleaf seeds survived at very low rates in soil (ca. 2 viable seeds at 24 months), and where the seedbank was not replenished, no viable seeds were present in the soil. Integration of compatible biotic agents can be an effective method for reducing seed viability before and after dispersal to the seed bank. Prevention of seed production is the foundation for successful weed management; effective insect plus microorganism combinations are key to this foundation in biologically-based weed management. |
