Biennial bearing of apple trees can be overcome either by the use of a blossom chemical thinner or by early application of a postbloom thinner. Carbaryl (Sevin) is a postbloom fruit-thinning chemical with an effective thinning period of 4 to 5 weeks after bloom. Sevin was compared in 1992 and 1993 with NAA as an early petal-fall spray. Sevin treatments reduced fruit set to one fruit per cluster...

Soil respiration is controlled by soil temperature, soil water, fine roots, microbial activity, and soil physical and chemical properties. Forest thinning changes soil temperature, soil water content, and root density and activity, and thus changes soil respiration. We measured soil respiration monthly and soil temperature and volumetric soil water continuously in a young ponderosa pine (Pinus ...

THINNING overdense stands to improve growth rate of trees is one way in which the nation's supply of merchantable timber can be increased significantly.' In the Pacific Northwest alone, several million acres of such dense precommercial stands would benefit from thinning. Two basic methods are used to thin dense forest stands—felling unwanted trees with saws or killing them with chemicals. Econo...