EVALUATION OF METALDEHYDE BAITS FOR CONTROL OF GRAY GARDEN SLUG IN ANNUAL RYEGRASS, 2005
Arthropod Management Tests
Gray Garden Slug (GGS): Deroceras reticulatum (Mueller) Pelleted metaldehyde slug baits, Deadline mini-pellets® and two lengths of Metarex® pellets (2.2mm and 2.5mm) were evaluated in Mar 2005 for control of GGS in an annual ryegrass field seeded the previous fall into minimum-til ground, Polk county, OR. Post-harvest straw residue was heavy. Plots, 50 × 50 ft., were replicated four times in a RCB design Eight treatments were applied to all plots on 2 Mar using a rotary, hand held bait spreader
... held bait spreader for higher treatment rates and a shaker jar for lower rates to achieve uniform coverage. Relative slug populations within plots were determined with bait stations prior to and after application of treatments (0, 7, 14, 21, 29, and 35 DAT). A bait station was an 8 by 12 inch area of soil scraped free of vegetation and equipped with 4 pellets of a cereal bran-based bait (2% metaldehyde plus 4% carbaryl). Three such stations were randomly placed in the interior of each plot in the evening. The following morning between 7 and 8 AM slugs within the stations were counted, recorded and removed (along with any remaining bait used in the station) from the field. Subsequent bait stations were re-randomized within all plots. Treatment efficacy was determined by comparing reduction of mean number of slugs recorded at the bait stations at different intervals post-treatment through time. Only larger juvenile and adult slugs that would have been present at time of baiting were recorded. During the fourth week of the trial, neonate slugs (< 2mm length) hatching from eggs deposited by slugs prior to pretreatment counts and after treatment baits had been consumed, appeared at the bait stations in small numbers. These were not included in the data. Rainfall totaling 13.5 cm was recorded at the site during the trial. Data were subjected to analysis of variance (ANOVA) and means were separated using the Fisher Protected (LSD, P = 0.05). All values were transformed using square root transformation to equalize the variance. Original means are presented in tables.