Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) ranging
from 9.6 to 14.3 inches diameter breast height were treated with
the organic arsenicals, monosodium methanearsonate (MSMA) and
cacodylic acid. Treatments were applied at monthly intervals from
February, 1967 to October, 1968, to ten to 25 trees each month.
Treated trees were sampled in...