Dwarfmistletoe on Red Fir and White Fir in California

·WHITE FIR (Abies concolor [Gord.] Engelm.) and red fir (A. magnifica A. Murr.) constitute nearly onefourth of the timber volume in California's commercial forests ( 1) and about one seventh of the annual lumber production in that area ( 6). These species are therefore of considerable concern to timber managers. One of the major problems in fir management is the dwarfmistletoe, Arceutkobiurn carnpylopodurn Engelm. Stands throughout the ranges of these fir species in California are heavily infected with this parasite and damage is extensive. Many questions arise regarding the treatment of mistletoe-infected fir stands. General recommendations for control of dwarfmistletoes are available to guide forest managers, but information dealing specifically with fir problems is limited. Investigations of dwarfmistletoe on firs have been undertaken to help meet the need for additional information. Initial results of these investigations and their possible significance in the s1lvicultural treatment of fir stands are presented here.