Effect of Silicon Applications on Reproduction and Development of Arthropod Pests on Horticultural Crops
Dr. Raymond Cloyd, University of Illinois, $20,000 1 year project
EXECUTIVE SUMMARY
The continual use of insecticides in horticultural cropping systems such as greenhouses has resulted in concerns associated with the difficulties of controlling insect pests due to resistance developing in insect pest populations, which has reduced the effectiveness of currently available insecticides. In addition, there are issues associated with the impact of insecticides on natural enemies (parasitoids and predators) and potential plant injury (phytotoxicity). This has led to an interest and opportunities in implementing alternative pest management strategies. As such, the purpose of this research is to determine the impact of silicon on the life history parameters of insect pests such as mealybugs and whiteflies that feed on horticultural plants under greenhouse conditions and correlate any negative effects with the concentration of silicon in plant tissue. One potential benefit of this research is that plants treated with either a drench or foliar application of sodium or potassium silicate will be less susceptible to insect pests or they will negatively impact the life history parameters of insect pests by either lowering egg loads (fecundity) and/or extending the developmental time period thus increasing exposure to insecticides or natural enemies.
The proposed research will result in both short-term and long-term benefits to the greenhouse industry by allowing greenhouse producers to use silicon-based fertilizers or supplemental applications of silicon to enhance plant resistance. The short-term benefits include in a reduction in insecticide costs due to the purchase of fewer insecticides and the need for fewer insecticide applications, resulting in a decrease in worker and customer exposure to insecticide residues that could instigate allergic reactions. Fewer insecticide applications will reduce the potential for plant injury resulting in healthier or less stressed plants. The long-term benefits include less susceptibility to regulatory issues related to groundwater and point source contamination of local waterways such as rivers and lakes. In addition, fewer insecticide applications will reduce the potential for spray drift onto non-target plants and less impace on natural enemies including honey and bumblebees, adn parasitoids and predators. Silicon is commercially available as potassium silicate (Pro-Tekt®; Dyna-Gro, San Pablo, CA), which means that application of our research could be readily and immediately incorporated in greenhouse production systems.
For further information contact Thomas German at tlg@entomology.wisc.edu
