California Agriculture, September 1959
Volume 13, Number 9
Plant parasitic nematode injury to California
Nematodes in plant quarantine: Detection of plant parasitic nematode infestations difficult because of complexity of possible causes of visible symptoms
by W. H. Hart
Abstract Not Available – First paragraph follows: Nearly all the major crop pests in California–including plant parasitic nematodes–have been introduced on or in host plants or as contaminants on articles of commerce. There are, however, a number of nematode species of serious economic importance in other parts of the world which are not known to occur in California. The golden nematode is a serious pest of potato in Europe and on Long Island, New York; the sting nematode injures many crops in the southeastern states; the soybean cyst nematode, in the Mississippi Valley and other southeastern states, attacks soybean, snapbean, and other plants of the bean family; and the burrowing nematode, reported to be the cause of spreading decline of citrus in Florida, are some of the nematode species not yet established in California.
Nematode structure and life: Wide range of life habits requires combination of characters for identification of parasites classified among nematodes
by A. R. Maggenti, M. W. Allen
Abstract Not Available – First paragraph follows: The many thousands of species of nematodes in the phylum Nemata are a group of animals commonly placed into four categories: parasites of man and animals; parasites of plants; species living in marine and brackish water; and free-living soil and fresh-water species. No single character or criterion can be used to distinguish nematodes from other similar animals, although one feature-not structural–sets nematodes apart, and that is the tremendous variation in size. Nematodes vary in length from the 1/125" ectoparasites of plants to the 25' long parasite of whales.
Field and vegetable crops: Wide ranges of crops and climatic conditions in California necessitate development of several diverse control programs
by Ivan J. Thomason, Bert Lear
Abstract Not Available – First paragraph follows: Nematodes of greatest economic importance are the several species of root-knot nematodes–Meloidogyne spp.–but pests such as the sugar-beet nematode– Heterodera schachtii–and the stem and bulb nematode–Ditylenchus dipsaci– are of major concern on specific crops.
Nematodes in grape production: Distribution records show multiple infestations of two or more species of nematodes to be in most of California's vineyards
by D. J. Raski, L. Lider
Abstract Not Available – First paragraph follows: Feeder roofs of grapes may be almost completely lacking in heavy nematode infestations.
Citrus and avocado nematodes: Spread by nursery stock, by contaminated implements, and by water from irrigation canals that may drain infested land
by R. C. Baines, S. D. Van Gundy, S. A. Sher
Abstract Not Available – First paragraph follows: Approximately 90% of the citrus trees in California are infested with the citrus nematode–Tylenchulus semipenetrans–which can reduce the yield of bearing trees and the growth of replants.
Deciduous fruit and nut trees: Root-knot nematode on peach and root-lesion nematode on walnut cause serious problems for California orchardists
by B. F. Lownsbery, E. F. Serr, C. J. Hansen
Abstract Not Available – First paragraph follows: Nematodes impair the root systems of trees by releasing toxins and by introducing secondary bacteria and fungi. Sometimes root symptoms make nematode activity evident, but in many instances these symptoms do not differ from those of other root-debilitating agents.
Nematodes on ornamentals: Root-knot, root-lesion, and more specialized or exotic forms may cause acute injuries in nursery, greenhouse, and garden
by S. A. Sher
Abstract Not Available – First paragraph follows: The root-knot nematodes are a limiting factor in growing ornamental plants –roses, carnations, Shasta daisies, gerbera daisies, and many others. Three species·–Meloidogyne incognita acrita, M. javanica javanica, and M. hapla–are commonly found on ornamental plants in California. Steam sterilization of plant beds or preplanting treatments of soil with nematocides have been effective in their control.
Biochemical relationships: Nematodes, plants, and linking soil components of complex problem of widespread, important pest of state's agriculture
by D. R. Viglierchio
Abstract Not Available – First paragraph follows: The problems associated with nematode diseases of plants can be visualized as one part of a system consisting usually of three components: nematodes, plants and the linking medium, most frequently soil.
Natural enemies of nematodes: Studies of complex soil environment aimed at favoring fungi and other organisms that limit plant nematode populations
by R. Mankau
Abstract Not Available – First paragraph follows: Nematodes are attacked by a variety of organisms including protozoa, fungi, and other nematodes. There are indications that some bacteria may cause reductions in nematode populations and, although no virus diseases of nematodes are known at present, some conceivably exist.
Chemical control of nematodes: Effective nematocides relatively few in number but available in several forms for field use on perennial and annual crops
by Bert Lear, N. B. Akesson
Abstract Not Available – First paragraph follows: The degree of control required from nematocidal treatments, application methods and rates vary from crop to crop. Less than 10 nematocides are available commercially, and only three or four of those were introduced within the past 15 years. Some nematocides are distributed in the soil by diffusion in the gas or vapor state, by water solutions or emulsions, or by mechanically mixing the chemical into the soil. Whatever the method, the chemical must be dispersed through the soil to kill nematodes to the desired depth, without leaving a phytotoxic residue.
Plant nematology in California: State's: Crop losses led to first department for research in plant nematology to be established by experiment stations
by M. W. Allen, A. R. Maggenti