| Popis: |
15 to 80 acre parcels of forested area in Ottawa county were used for this test. All Bacillus thuringiensis (Bt) treatment plots were ones that qualified for the Michigan Cooperative Gypsy Moth Suppression Program administered by the Michigan Department of Agriculture. These areas contained primarily poplar and oak. On 14, 21, and 28 Apr two 1/40 acre circles were sampled in each treatment block for all visible new egg masses. Each Bt treatment was replicated 4 times with each replicate being a separate wooded parcel. Four areas not slated for treatment near the treatment blocks were also sampled for egg masses for comparison. The treatments were applied on 30 May between 9 am and 1 pm. The wind was calm with gusts at about 3-9 mph. The humidity started out low, but gradually increased until it was approximately 50% by 1 pm. The treatments were applied by a Bell 47 helicopter using six 5000 Micronair nozzles. On 28 Jun twenty white oak, red oak, and poplar trees were sampled by a group of 4 people and evaluated for the percentage of defoliation. Each person in the sampling team rated 5 trees. |
