Robert F. Scharpf

A User's Guide to a FAMULUS Retrieval System

Mistletoe Literature of the World

One Seed Source of Jeffrey Pine Shows Resistance to Dwarf Mistletoe

Frank G. Hawksworth

Ed F. Wicker

Fungal Parasites of Dwarf Mistletoes

Seed Production and Dispersal by Dwarf Mistletoe in Overstory Jeffrey Pines in California

Young red firs (Abies magnifica A. Murr.) and white firs (A. concolor [Gord. & Glend.] Lindl. ex Hildebr.) on the Stanislaus National Forest, California, were inoculated with seeds of dwarf mistletoe (Arceuthobium abietinum) for 5 successive years. Only 3 to 4 percent of about 7000 seeds placed on branches resulted in infections. Second-generation infections developed and populations of the parasite built up on some trees but not on others after 17 years. Variables that appeared to regulate population increases included an 8- to 9-year average between inoculation and fruiting of plants, low rate of fruit production among female plants, low proportion of plants producing abundant fruit (100 or more/year), and irregular production of fruit on plants over the years, Death of infected branches also helped keep populations of the parasite in check. In vigorous, well-managed stands of young firs, dwarf mistletoe populations may not build up rapidly enough to result in serious losses.

Population Dynamics of Dwarf Mistletoe on Young True Firs in the Central Sierra Nevada, California

Resistance of Ponderosa Pine to Western Dwarf Mistletoe in Central Oregon

Infection and Control in Understory Stands

Dwarf Mistletoe on Red Fir

A disease of Jeffrey pines (Pinus jeffreyi Grev. and Balf.) at Lake Tahoe Basin, California, caused by Elytrodenna disease (Elytroderma deformans) was studied for 7 years after a severe outbreak of the fungus in 1971. Among 607 Jeffrey pines on six plots, about one-half were heavily infected and about one-half were moderately or lightly infected in 1971. No uninfected trees were observed. During the 7-year study, about one-half of the trees remained unchanged in vigor, disease intensity, or both, and about one-half decreased in vigor, became more heavily infected, or both. Of the original 607 trees studied, nearly one-third died before 1978. Average radial growth of surviving trees was less per year after the outbreak than before, and heavily infected trees were growing more slowly than lightly infected trees. Intensity of the disease, however, was not related to stand basal area.

Elytroderma Disease Reduces Growth and Vigor, Increases Mortality of Jeffrey Pines at Lake Tahoe Basin, California

J. R. Parmeter

Rate of population buildup of dwarf mistletoe, Arceuthobium abietinum Engelm. ex Munz., was slow in most small red firs and white firs 12 to 15 years after inoculation with the parasite. Where population buildup did occur, it remained clustered in the lower portions of tree crowns near inoculation sites. Maximum distance of vertical spread was 16 feet (4.8 m), after 15 years. The mean annual rate of vertical spread of the parasite in 12 to 15 years was 3 inches (7 cm) or less in test trees. No vertical spread occurred in some trees. Rate of vertical spread was much slower in all trees than the mean annual height growth of vigorous young red or white firs. Therefore, the test trees were outgrowing the spread of dwarf mistletoe within tree crowns. Vertical spread rate and rate of tree height growth together determine the proportion of tree crown that will be infested at a given time after inoculation.

Population Buildup and Vertical Spread of Dwarf Mistletoe on Young Red and White Firs in California

Thomas W. Koerber

David L. Wood

Andrew J. Storer

"This book provides an important compilation of information on major pathogens, insects, and other pests of conifers. Because conifers are of tremendous ecological and economic importance in California, this book will fill a unique niche."—Dave M. Rizzo, University of California, Davis "I applaud the authors for the effort involved in assembling this book. The combination of insect and disease information has important reference and diagnostic value."—Timothy D. Paine, co-editor of Mechanisms and Deployment of Resistance in Trees to Insects

Pests of the Native California Conifers

Cytospora Canker of True Firs

Robert F. Scharpf

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