Biological Control of Insects With Insect-Pathogenic Nematodes - A Brief Status Report

Increased interest in using biological control of insects by nurseries prompted the author to provide the brief report on using pathogenic nematodes for insect control. Topics discussed include nematode species, nematode lifecycle, host insects, and other factors.

Rhododendron Leaf Spot and Stem Dieback Caused by Phytophthora syringae

Plant Disease
Research conducted by Dr. R. G. Linderman on rhododendron leaf spot and stem die back determined both to be caused by Phytophthora syringae. Details about the effects and lifecycle of the fungus and possible control methods are provided.

Effects of Raised and Ground-Level Beds and Pine Bark on Survival of Azalea and Population Dynamics of Phytophthora innamomi.

Nursery Crops
North Carolina State University affiliated authors conducted a study to investigate the effects of planting azalea in raised and ground-level beds and pine bark. The study examined the survival rate of the plants and the population levels of Phytophthora innamomi.

Atrazine - Herbicide Degradation, Carry Over, and Buildup

Oregon State University extension agent specializing in horticultural weeds discusses the herbicide atrazine. Specific topics addressed by the author include; herbicide degradation, carry over, buildup, and management of herbicide residues in horticultural crops.

Quackgrass-A Serious Problem Weed

Quackgrass (Elymus repens L. Gould) is a perennial problem weed of the cooler climates in the Northern Hemisphere. Quackgrass reproduction and spread, competition with crop plants, and quackgrass control methods are addressed in the article.

Oxalis-Biology and Control

Oxalis (Oxalis europaea), known also as Yellow Wood Sorrel, is a persistent weed with characteristic explosive seed dispersal from elongated pods. The University of California affiliated authors emphasize the importance of understanding seed production, dispersal, and germination.

Control of Yellow Nutsedge in Nurseries

Yellow nutsedge (Cyperus esculentus) is a persistent weed, especially in cultivated areas, that grows well in varying habitats with different environmental conditions. Information is provided on the following topics; identification, life cycle, infestation, controls, and year-round management.

Nutrient Analysis Problems in Douglas-fir Christmas Trees

Christmas Tree
The results of an Oregon State University affiliated two year study on the nutrient levels of Douglas-fir trees on Oregon Christmas tree plantations. Samples were taken from trees four and five years old in the Corvallis, OR and Willamette Valley areas.

Necrotic Ringspot on Bluegrass Turf

Plant Disease
Research conducted at Washington State University's Western Research and Extension Center identified the cause of "necrotic ringspot" on bluegrass turf to be the fungus Leptosphaeria korrae. The authors discuss the signs and symptoms of the disease along with control methods.

Swiss Needle Cast of Douglas-Fir

Plant Disease
Swiss needle cast (Phaeocryptopus gaumanni) is a fungal disease of Douglas-fir trees, native to the North American pacific coast, which causes needle and color loss. Topics discussed include, winter-spring symptoms, summer-fall symptoms, and control.