California Agriculture, September-October 1989
Volume 43, Number 5
Intensive grazing on annual range
peer-reviewed research articles
Managing yellow starthistle on rangeland
by Craig D. Thomsen , William A. Williams , Melvin R. George , W. B. McHenry , Fremont L. Bell , Ronald S. Knight
Intensive cattle grazing in May and June reduced yellow starthistle plant size, summer and fall canopy size, and seed production in the first year of a 3-year, northern California study. Combining grazing and herbicide applications caused large reductions. Abundant late rains favored yellow starthistle growth.
Improving orchard soil structure and water penetration
by Daniel C. Moore , Michael J. Singer , William H. Olson
Soil surface crusts can severely limit water infiltration and tree crop production. Vegetative cover and gypsum treatments in an orchard increased soil structural stability and may reduce crust formation in the long term. Tillage improved short-term water penetration by temporarily breaking up the crust.
The ‘Achilles heel’ of pistachio fruit
by Themis J. Michailides
A small area at the stem end of the pistachio fruit, which hardens later than the rest of the tissues, is susceptible to puncturing by several insects during the growing season. Studies found that 60% to 74% of the kernel damage symptoms were at the stem end and along the suture areas.
Verticillium wilt found in southern California alfalfa
by Donald C. Erwin , Rudolph A. Khan , Amy Howell , Abdelaziz Baameur , Steve B. Orloff
The disease has been found in alfalfa south of the Tehachapi Mountains, but not yet in the Central Valley of California. High summer temperatures do not seem to be a barrier to the fungus, and several alfalfa cultivars as well as cowpea were susceptible in greenhouse tests.
Survey detects viruses in almond, prune, and sweet cherry orchards
by Jerry K. Uyemoto , Joseph A. Grant , William H. Krueger , William H. Olson , Joseph W. Osgood , G. Steven Sibbet , Mario Viveros , Craig V. Weakley
Prunus necrotic ringspot and/or prune dwarf viruses were found in young California orchards, averaging 20% infection in almond and prune and 4% in sweet cherry. Nursery stock was implicated as the primary source, and efforts are now under way to propagate disease-free trees.
Intensive grazing increases beef production
by Melvin R. George , Ronald S. Knight , Peter B. Sands , Montague W. Demment
Beef production per acre on a foothill range livestock operation increased under an intensive, rotational grazing system. There were management problems, but they were outweighed by the benefits.
Growth regulator controls tomato transplant height
by Gary W. Hickman , Edward J. Perry , Robert J. Mullen , Richard Smith
A new plant growth regulator, uniconazole, controlled height of greenhouse-grown fresh market tomato transplants in a 1-year trial. Field results showed no effect on final yields and quality.
Guthion-resistant walnut aphid parasite: Release, dispersal, and recovery in orchards
by Marjorie A. Hoy , Frances E. Cave , Robert H. Beede , Joseph Grant , William H. Krueger , William H. Olson , Kevin M. Spollen , William W. Barnett , Lonnie C. Hendricks
A genetically improved strain of the parasite Trioxys pallidus performed well after release in commercial orchards in 1988, persisting through the season in four of the five release sites and, at two sites, dispersing to nearby wainut blocks. Work on the resistant strain also continued in the laboratory, as reported in the next article.
Parasite tolerates other pesticides
by Marjorie A. Hoy , Frances E. Cave
Laboratory tests with field-collected foliage showed the selected strain of Trioxys pallidus was also resistant to Lorsban, Thiodan, Supracide, and Zolone, pesticides used in walnut IPM programs.
Computerized corral feed stations for dairy cows
by Thomas A. Shultz
The mechanical feed stations monitored the feed intake of individual cows fed in large groups, making it easier to spot changes in each animal's condition.
Tailoring Cooperative Extension programs to serve home gardeners
by Dennis R. Pittenger , Vincent Lazaneo
A survey of households in San Diego County suggests that Cooperative Extension could most effectively deliver its university-based information to home gardeners through nurseries and similar professional sources rather than directly. Gardeners preferred those information sources for their convenience.
Several copper fungicides control olive leaf spot
by Beth L. Teviotdale , G. Steven Sibbett , Dennis H. Harper
Tests evaluated control of olive leaf spot disease by several copper-containing fungicides and by various rates of Bordeaux mixture. Copper residues in all treatments were also monitored. There were differences among treatments in retention of copper residues but not in disease control.
Update on procedures for prospective RAWs
by Howard R. Rosenberg
Abstract Not Available – First paragraph follows: According to an “interim final rule” issued on July 17, eligible aliens who want any chance of being selected for legal status as replenishment agricultural workers (RAWS) from October 1, 1989, through September 30,1993, have to register before November 1, 1989. This version supersedes a proposed rule issued last March that covered only the first year of the RAW program established under the Immigration Reform and Control Act of 1986 (IRCA) (see “SAW employment data and the need for RAWs,” California Agriculture, May-June 1989).
editorial, news, letters & science briefs
Biological control: Major emphasis in UC research
by Seymour D. Van Gundy