Toxicity of herbicides on three northwestern conifers.

Abstract

Vigorous natural reproduction of Douglas-fir, sugar pine, and ponderosa pine in southwestern Oregon was sprayed with 1/2-pound aehg solutions of low volatile esters of 2, 4-D and 2,4, 5-T during 1956. When treated, the trees averaged 4 to 8 feet in height. Treatments were applied during the period of active growth in midsummer and repeated in early autumn after height growth had ended and buds were set. The chemicals were applied in three different carriers: (1) water, (2) water plus spreader-sticker, and (3) a 5-percent diesel oil emulsion. Extent of damage from these treatments was determined by examination in October 1957 and September 1958.

Citation

Gratkowski, H. 1961. Toxicity of herbicides on three northwestern conifers. PNW Old Series Research Paper No. 42: 1-24