2012 Annual Report
1a.Objectives (from AD-416):
1. To discover and evaluate new biopesticides against sweetpotato insects.
2. To develop relationship between sweetpotato root damage and insect population density.
3. To determine correlation between wireworm larval population and adult trap catch.
4. To detect sweetpotato weevil (Cylas formicarius) populations in quarantined counties of southern Mississippi by using pheromone traps.
5. To promote sweetpotato production practices through outreach activities (field days, growers’ meetings and field demonstration plots).
1b.Approach (from AD-416):
New botanical and other biological compounds will be extracted and evaluated against major sweetpotato insect pests. New and conventional sweetpotato varieties will be evaluated for root damage by insects. Root damage will be correlated with insect pest numbers collected by using different sampling methods. Seeds of corn, wheat and crimple oats will be used in bait treatments to collect wireworm larvae in sweetpotato fields. Relationship of adult beetles will be established with wireworm larvae captured in bait traps. Pheromone traps will be used to detect adult Cylas (C.) formicarius population in southern Mississippi. The knowledge gained through research will be dissipated through seminars, research publications, internet, presentations in professional meetings, on-farm demonstrations and workshops.
Sweetpotato weevil pheromone traps have been placed in Copiah County, MS, (Crystal Spring, MS, area) near ornamental sweetpotato research plots. Sweetpotato research plots have also been established in Claiborne County, MS, (Alcorn State University main campus area). Pheromone traps will be installed around these plots and checked every 2 weeks for any weevil population detection.
During previous years the purple sheet sticky traps have shown promising results in attracting adult wireworms especially Conoderus (C.) vespertinus. New 4-wing bucket traps have been designed and constructed with similar purple sheets for the collection of adult C. vespertinus. A laboratory colony will be started and maintained for adult/larvae toxicity bioassays with several biopesticides.
An Alcorn State University (ASU) undergraduate student in Agriculture has been hired to assist in a study to evaluate Prohexadione Calcium (Ca) effect on yield and insect damage to several varieties of sweetpotatoes. Sweetpotato plots have been established in ASU Extension/Research Demonstration Farm and Technology Transfer Center, Mound Bayou, MS. Each research plot consists of 2 rows each 25-feet long in two water regimens (irrigated and non-irrigated). Each sweetpotato variety has 4 replications with or without Prohexadione-Ca applications. The test variables are root damage, growth rate, chlorophyll amount and leaf area. The plots will be harvested to determine yield and insect damage in different treatments.