March-April 1988

Cover: Huge fields of flowers being grown for seed, such as these marigolds and petunias, are common sights in the Lompoc Valley of California near Santa Barbara. Marigolds are also grown for seed in large commercial greenhouses, where the leafminer is a pest. This article reports on the use of a parasitic wasp to control leafminers in greenhouse marigolds. Photo courtesy Bodger Seeds, Ltd., of Lompoc.

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California Agriculture, March-April 1988

Volume 42, Number 2

peer-reviewed research articles

Sustained-release bolus for deworming dairy heifers
by Thomas A. Shultz , E. Michael Huffman , Norman F. Baker
pp4-5, doi#10.3733/ca.v042n02p4
Abstract
Abstract Not Available – First paragraph follows:A major source of gastrointestinal worm infestation of grazing heifers is larvae that have survived the winter on pasture grass. When these larvae are swallowed and mature inside the heifer, they produce eggs that are shed in the feces, resulting in a higher pasture contamination later in the grazing season. To break this recycling of pasture worm infestations, multiple deworming is needed. This adds labor and other costs, since the heifers are on pasture and may not be easily accessible.
Expanded Abstract | PDF

What about 4-H?
by Robert E. Savage
pp6-7, doi#10.3733/ca.v042n02p6
Abstract
Abstract Not Available – First paragraph follows:Modoc Countv's 4-H re-enrollment began declining inihe early 1980s from a 20-year average of 70 percent to 59 percent in 1983. Since the percentage of return membership reflects the degree to which the 4-H program is meeting clientele needs, re-enrollment is the major indicator of the program's quality. To learn why youth remain in, or leave, 4-H in Modoc County, I conducted a study over a three-year period, 1984-86.
Expanded Abstract | PDF

The epidemiology of powdery mildew on tomatoes
by James C. Correll , Thomas R. Gordon , Vern J. Elliott
pp8-10, doi#10.3733/ca.v042n02p8
Abstract
Fresh market tomatoes are susceptible but yields don't seem to be affected
Expanded Abstract | PDF

Biological control of leafminers on greenhouse marigolds
by Kevin M. Heinz , Julie P. Newman , Michael P. Parrella
pp10-12, doi#10.3733/ca.v042n02p10
Abstract
In greenhouse marigolds grown for seed, a parasitic wasp suppressed leafminers for two months after establishment
Expanded Abstract | PDF

Predicting vineyard pruner performance
by Gregory Encina Billikopf
pp13-14, doi#10.3733/ca.v042n02p13
Abstract
A job-sample test showed high correlation with work performance
Expanded Abstract | PDF

A new marketing era for California specialty crops
by Harold O. Carter , Carole Nuckton
pp15-20, doi#10.3733/ca.v042n02p15
Abstract
The rules may have changed, but California producers of specialty crops seem to have reason for cautious optimism, at least for the near term. The longer term outlook is uncertain and may depend on new marketing techniques and new technology.
Expanded Abstract | PDF

Added fat in dairy feed decreases milk protein
by Edward J. DePeters , Scott J. Taylor , Curt M. Finley , Thomas R. Famula
pp21-22, doi#10.3733/ca.v042n02p21
Abstract
The practice may reduce rather than increase cheese yield
Expanded Abstract | PDF

Estimating saline water table contributions to crop water use
by Mark E. Grismer , Timothy K. Gates
pp23-24, doi#10.3733/ca.v042n02p23
Abstract
Abstract Not Available – First paragraph follows:Researchers in several western states have found that, under arid conditions, water tables can supply as much as 60 to 70 percent of a crop's water requirement. Use of high water tables reduces irrigation needs, lowers production costs, reduces deep seepage losses, and decreases the volume of drainage water requiring disposal. Successful use of the water table also depends on the soil's water retention and transmitting properties, evapotranspiration (ET) demand, distribution of the plant root system, and salinity and toxic ion effects on crop growth. Under field conditions, many of these factors are part of the overall crop response to the saline.
Expanded Abstract | PDF

A new disease of myrtle
by Amy Lutz , Albert O. Paulus , Donald M. Ferrin , Jerry A. Nelson
pp24-25, doi#10.3733/ca.v042n02p24
Abstract
Cylindrocladium root and crown rot, once established, is difficult to control
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Blacklight monitoring of two avocado insect pests
by J. Blair Bailey , Michael P. Hoffmann , Kirk N. Olsen
pp26-27, doi#10.3733/ca.v042n02p26
Abstract
Early summer flights are generally the largest, and likely to cause the most damage
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Diagnosing nutrient needs of garlic
by Kent B. Tyler , Donald M. May , John P. Guerard , David Ririe , James J. Hatakeda
pp28-29, doi#10.3733/ca.v042n02p28
Abstract
Phosphorus and zinc fertilizers are rarely required. Only moderate amounts of nitrogen are needed for top yields.
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New psyllid pest of California pepper tree
by James A. Downer , Pavel Svihra , Richard H. Molinar , Jack B. Fraser , Carlton S. Koehler
pp30-31, doi#10.3733/ca.v042n02p30
Abstract
Abstract Not Available – First paragraph follows:A new psyllid pest of California pepper trees was first discovered in Long Beach, California, in July 1984. Since then, the insect has spread rapidly, particularly in coastal areas, and now occurs from San Diego County to the San Francisco Bay region. There are scattered records of its occurrence inland in San Bernardino and Kern counties.
Expanded Abstract | PDF

editorial, news, letters & science briefs

EDITORIAL: Agricultural technology: Put the genie back in the bottle?
by Kenneth R. Farrell
pp2, doi#10.3733/ca.v042n02p2
PDF