| Popis: |
On 18 Nov, 24 3-ft yews (12 each of ‘Densiformis’ and ‘Hicksii’) were dug B & B from a commercial nursery in Broadbrook, Hartford County, Conn., and transferred to a containment area at the Connecticut Agricultural Experiment Station in New Haven. On 25 Nov, the 24 yews were randomly assigned to 4 groups. Three groups were treated the same day with foliar insecticides; the other group served as the untreated check. Treatments were applied by Solo Jetpak 425 backpack sprayer. Two liters of mixed solution was applied to each tree to drench the foliage completely. All living scales were second-instar nymphs at the time of treatment. When the foliage had dried (4 h later) the trees were moved into a glasshouse, where they were maintained under natural lighting at 15°C and watered as needed. Three wk later the general appearance of each group was recorded and each yew was sampled by removing 20 randomly selected 10-cm-long branches/plant. The branches were examined by microscope and the first 5 scales encountered on each branch were recorded as dead or alive. Plants Were kept throughout the winter and checked periodically for evidence of phytotoxicity. |
