An experiment was started in the fall of 1972 to study the effects of the date of fall lifting on the post-planting performance of overwinter stored white spruce and jack pine. Storage at two temperatures was used, 0°F (−18 °C) and 26°F (−4 °C), with the former a failure, the latter successful. Spring planting indicated that "too early" outplanting is possible. Stored white spruce may be used to extend the planting season into late spring, but not jack pine.Degree-Hardening-Days, D-H-D, i.e. cumulative daily differences below 50°F from soil temperatures at 15 cm depth, is suggested as a possible criterion of stock readiness for storage. White spruce was about 200 D-H-D and jack pine about 375. By inferences from other experiments white pine is about 225 D-H-D and red pine about 300.
Trials were carried out in Upper Volta to assess equipment for the application of insecticides as aerosol from helicopters for the control of riverine tsetse flies (G. tachinoides). Flying ti :hniques were developed to direct aerosols in the downwash of the helicopter to tsei a breeding sites close to the water's edge. Good penetration of droplets below the riverine canopy was achieved during the late afternoon and early morning when weather conditions were very stable.
Fall lifted white spruce, white pine, and red pine were stored overwinter 1969–70 at Orono Nursery, Ontario. Frozen (−4 °C) and cold (1.5 °C) storage conditions; bales and polyethylene bags were compared. The trees were planted in the spring at three locations, both 'early' (May 5–8) and 'late' (May 26–28). This report is based on survival, height, and terminal shoot measurements to the end of the second season.Storage of white spruce was successful, the polybag was the better container, and frozen storage the better condition. White pine stored moderately successfully, and red pine storage was a failure.When planted late, fresh stock gave poor growth rates in all species. Reasonable extension of the planting season with frozen overwinter-stored stock appeared promising with white spruce. In white pine and red pine, however, late planting, even of stored stock, showed poor growth.
IntroductionSynergised pyrethrins topically applied are highly toxic to Glossina morsitans Westw. (Burnett, 1961) but have generally been considered too costly for large-scale aerial control measures. This paper describes an experiment run in 1967 to evaluate the economics and the eflFect of the aerial application of pyrethrum on a high density of tsetse fly, the objective being complete eradication.
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