Past Research – Page 2

2005 M. Arpaia ( SSCTA ratio )

Relationship Between SSC/TA Ratio and Acceptability of Navel Orange

During the second year of this project, we continued the work initiated last year. This project uses the sensory panel volunteers at the UC Kearney Ag Center to evaluate early season navel oranges with the intent to develop a database of the relationship between SSC/TA ratio, volatiles, and acceptability of navel orange fruit. Additionally, during this year we explored the relationship between fruit handling practices, waxes and fruit acceptability following storage.

2005 J. Leesch (Efficacy of Ozone Combination Treatment…)

Efficacy of Ozone Combination Treatment to Control Bean Thrips in Navel Oranges

This research investigates the efficacy of ozone combined with carbon dioxide and vacuum to control bean thrips in navel oranges. A focus of this work in 2004-2005 was effects of wax type and cultivar to mitigate phytotoxic damage.

2005 J. Thompson ( Survey of Sensing Methods for Detection of Freeze Damage in Oranges)

Survey of Sensing Methods for Detection of Freeze Damage in Oranges

The goal of this project is to develop and test a field method for using an ethanol sensor to measure whether a sample of oranges contains a threshold level of freeze-damaged fruit. The citrus industry is seeking an objective alternative to the manual inspection method used by CDFA inspectors to determine freeze damage in navel oranges.

2005 J. Smilanick ( New Methods to Control Postharvest Decay of Citrus )

New Methods to Control Postharvest Decay of Citrus

The purpose of this project is to develop new methods to control postharvest decay of citrus for use in California packinghouses. Practical experiments with the newly approved postharvest fungicide pyrimethanil (PYR) were completed in 2005. PYR has recently been approved for use in California to control green mold, caused by Penicillium digitatum, though acceptance of its residues in some overseas markets is still in progress.

2005 J.E. Adaskaveg ( Evaluation of New Postharvest…)

Evaluation of New Postharvest Treatments to Reduce Postharvest Decays and Improve Fruit Quality in Citrus Packinghouse Operations

In the summer of 2005, fludioxonil and pyrimethanil were registered in California following the federal registration in the fall of 2004 for postharvest use on citrus. The postharvest registration of azoxystrobin is still pending but is expected in the summer of 2006. In Sept. 2005, we successfully placed propiconazole into the federal IR-4 program to establish a residue tolerance for postharvest use, and these studies are planned for 2006.

2005 Roger Vargas ( Evaluation of Fipronil….)

Evaluation of Fipronil in Male Annihilation and Ground Treatments for Control of Mediterranean Fruit Fly, Oriental Fruit Fly and Melon Fly

Economically important fruit flies in the family Tephritidae are among the most serious agricultural pests throughout the Pacific region. Conventional fruit fly area-wide control methods such as bait spray, male annihilation and ground area-wide treatments rely heavily on organophosphate (OP) insecticides. Continued registration of many OP insecticides for use in the U. S. is in doubt.

2005 Headrick/Grafton-Cardwell (Field Management Plan and Biocontrol Rearing System for Citrus Peelminer)

Field Management Plan and Biocontrol Rearing System for Citrus Peelminer

Objective 1 – Development of a pheromone-based monitoring system. Valley-wide trap deployment in the San Joaquin Valley took place from February to October with new lures developed by Dr. Jocelyn Millar, UC/Riverside. Fifty-one commercial orchards, 9 citrus/other hosts sites, plus 4 pummelo sites were utilized in the study. The trap data were inconclusive this year – there was about 1 flight per month, with adjacent crops having a large effect on subsequent citrus infestations.

2005 Raymond L Hix (Glassy-Winged Sharpshooter Impact on Orange Yield, Fruit Size, and Quality)

Glassy-Winged Sharpshooter Impact on Orange Yield, Fruit Size, and Quality

Prior to this study, it was unknown what impact the glassy-winged sharpshooter (GWSS), Homalodisca coagulata, had on orange yield, size, and quality as well as tree vigor. The goals of this project were to determine the usefulness of management of GWSS to prevent yield loss, fruit size reduction, and degraded fruit quality. This information is paramount before we can even begin to incorporate these into conventional IPM programs. First we needed to know what if any, impact GWSS has on citrus. Secondly we needed to know how to use the currently available materials against the GWSS in IPM programs to prevent potential losses without disrupting citrus IPM programs. Prior to this study, efforts to manage GWSS in California citrus were primarily to suppress populations to limit the spread of Xylella fastidiosa in areawide management programs.

2005 R. Stouthamer/R. Luck (Reducing the Negative Impact of Bacterial Infections)

Reducing the Negative Impact of Bacterial Infections in Aphytis melinus

About 70% of all insect species are infected with Wolbachia, a bacterium. Aphytis is no exception. Some Wolbachia infections can be beneficial such as those causing their hosts to produce female offspring exclusively, while others can be negative such as those that affect the efficacy of biological control.

2005 Jocelyn Millar (Development of Pheromone Traps for Monitoring Citrus Leafminer)

Development of Pheromone Traps for Monitoring Citrus Leafminer

The citrus leafminer (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) is a problem for growers in most of regions of the world where citrus is grown (Heppner 1998). Grapefruit, tangerine, and pummelo are among the most susceptible hosts, but the leafminer can attack all varieties of citrus and some related plant species (Legaspi and French 2003).