ABSTRACTS

Birch, M.E. et al. 1977. Pheromone traps to suppress populations of the smaller European elm bark beetle. California Agriculture 31(11): 4-6.

The principal vector for the Dutch elm disease pathogen is the smaller European elm bark beetle. The beetles, known since 1951 to occur in California, reproduce in dead or dying elm wood. Feeding that occurs in the spring or early summer results in general infections because the spores can be quickly carried to all parts of a tree by the long xylem vessels of the spring wood. Using the aggregation pheromone (multilure) as a bait, sticky card traps can be used to kill large numbers of this beetle. We have been conducting a study to determine the efficacy of a pheromone based trap-out strategy to reduce the size of isolated populations of bark beetles in eastern California.

Edwards, Art. 1978. Vegetation management. Grounds Maintenance 13(2): 24-25, 28, 30.

Plans for vegetation management today include much more than merely knocking down excess growth, particularly weeds and brush. For a number of years utilities have been hiring qualified technical people who know every sprig of vegetation, and how it may or may not fit into an aesthetically pleasing and usable right of way. Chemical control today should consist of selectively killing only those species which unduly limit access or which may endanger the power lines. Plant communities are more or less planned and maintained to utilize as many native species as possible with only the undesirable tree species being killed off. Overall beautification is the key and brown-out, where total populations are killed off, is limited to less sensitive geographic areas. Turfgrass managers, golf superintendents and others need technical knowledge as never before. Their position is always sensitive because any use of chemicals must conform environmentally. Yet park visitors, golfers, and others who use turfgrass or merely enjoy it aesthetically seldom opt for lesser quality. The new season will be no different. Users still want the best. Following are case histories which exemplify successful applications.

Shurtleff, M.C. 1978. Why not grow disease-resistant trees? Grounds Maintenance 13(2): 38, 40, 43-44, 46.

The ideal method of controlling troublesome tree diseases is to grow resistant varieties (cultivars) and species. Selecting and growing such trees, where well adapted, will reduce your maintenance costs since these plants are less likely to require special sprays or additional care for disease control. Selecting resistant cultivars can reduce maintenance time and costs because such trees require less specialized care. This article, first in a series, recommends varieties resistant to Phomopsis blight, Verticillium wilt, crown gall, and leaf blotch.