Treesearch

Size of aspen crop trees at age 15 years is essentially the same for a wide range of initial sucker densities. High densities are not necessary to produce adequately stocked stands.

Jack pine foliage infested with jack-pine budworm egg masses was examined under two kinds of light -- black light and a combination of natural and fluorescent light. Black light significantly increased the accuracy of count but not the efficiency of examination.

Five winter-cut northern species were chipped in a frozen and unfrozen condition with a parallel knife chipper. The degree of bark separation during chipping and a relative gradation of chip size are reported.

Most of the lumber produced in northern Minnesota is marketed in Minnesota, and the marketing area increases as mill size increases. Aspen is a dominant species. About 45 percent of the lumber is graded; concentration and grading would improve marketing. Less than one-third of the by-products are marketed

In 5-year-old test plantations in Minnesota, Wisconsin, and Michigan, eastern white pine seedlings from seed sources that are fast-growing in one location are not necessarily fast-growing in other locations. Until more intensive studies of the Lake States seed sources can be made, foresters should confine collection of white pine seed to local stands.

Commercial forest land has declined slightly from 4.1 million acres in 1950 to 3.9 million acres in 1967. The more heavily forested counties are in the southern half of the State where forest land has been increasing

Cherry bark oak acorns exposed to air lose moisture rapidly resulting in delayed or complete lack of germination

To prevent blister rust infections in Eastern white pine seedlings, the antibiotics, cycloheximide (acti-dione) and Phytoactin, were tested in root dips, root slurries, and foliar drenches before planting and after planting the trees. None of the methods and materials tested was effective.

Second-year cone crops in red pine seed-production areas have been severely damaged by five species of insects. Control of the two most destructive pests could increase present seed yields in most areas by at least 50 percent. Some seed-production areas may not produce harvestable seed crops until cone-insect populations are suppressed.

Fuel changes resulting from aerial herbicide application to control hardwoods competing with 13-year-old underplanted pine in Missouri are described. Fuel hazard is generally maximum about the fifth year after treatment and is affected by relative pine and hardwood densities.