Menu

Plant Pathology

2005 J.E. Adaskaveg (Septoria)

Biology and Management of Septoria Spot of Citrus

Septoria spot of citrus caused by Septoria citri is found in many citrus-producing countries around the world. It is a sporadic disease in California with most reports coming from Tulare Co. and Fresno Co. The pathogen is present on leaves and twigs in many orchards, and fruit infections probably occur commonly. Disease from these quiescent infections, however, only develops when plant tissues become senescent or environmental conditions predispose the host to infection.

More…

2005 Robert R. Krueger Final Report (Stubborn Disease in the Field)

Development of a Rapid System for Detection of Stubborn Disease in the Field

Stubborn disease of citrus, caused by Spiroplasma citri, is an important disease of citrus in the hot, arid inland areas of California and Arizona. The two methods most commonly used for detection of stubborn have been biological indexing and culture in a cell-free medium. Indexing for stubborn disease of citrus is difficult since it requires the somewhat tricky side-graft or leaf vein method, and it takes several months to obtain results. Culturing is also somewhat time consuming, sometimes requires several attempts, and can produce false positives from contamination. Culturing is the test of record for CDFA and most regulatory agencies.

2005 Edwin Civerolo (Database for Microarray-based Detection Systems)

Development and Management of a Genomics Database for
Microarray-based Detection Systems for Citrus Pathogens

The specific objective is to develop and manage a database of genomics information related to citrus pathogens and infection and to citrus pathogen-host interactions. The main targeted citrus pathogens for this project are Xylella fastidiosa (Xf), citrus tristeza virus (CTV) and huanglongbing (HLB).

2005 J.E. Adaskaveg (Hyphoderma Gummosis)

Etiology, Epidemiology, and Management of Hyphoderma Gummosis

Hyphoderma gummosis, caused by the Basidiomycota fungus Hyphoderma sambuci, was first observed in Tulare County in 2000. In surveys done in collaboration with farm advisors Ben Faber and Neil O’Connell, the disease was subsequently found in numerous lemon orchards in Ventura, Tulare, as well as Riverside and San Luis Obispo Counties.

2005 J.E. Adaskaveg (Septoria Spot of Citrus)

Biology and Management of Septoria Spot of Citrus

Septoria spot of citrus caused by Septoria citri is found in many citrus-producing countries around the world. It is a sporadic disease in California with most reports coming from Tulare Co. and Fresno Co. The pathogen is present on leaves and twigs in many orchards, and fruit infections probably occur commonly. Disease from these quiescent infections, however, only develops when plant tissues become senescent or environmental conditions predispose the host to infection.

2005 Marylou Polek (Tristeza Virus Strains)

Biological Characterization of Naturally Occurring Citrus Tristeza Virus Strains in California Citrus and Maintenance of the Isolate Collection

This project is not a typical research project. Rather, it is one that largely supports the research of several laboratories including those located at the University of California at Davis, UC Riverside, USDA Parlier, USDA Riverside, Thomas Jefferson University, and AgDia (a private company). This report will summarize the services and materials provided to these laboratories.

2008 Lee and Vidalakis (HLB Management Systems )

Huanglongbing: Development of Information Needed for Avoidance/Management

This is year one of a three-year project having five objectives. The purpose of this project is to provide information that is critical to avoiding HLB in California and to gain practical information that would enable better management of HLB should it appear in California in the future.

2008 James E Adaskaveg (Hyphoderma Gummosis Studies)

Etiology, Epidemiology, and Management of Hyphoderma Gummosis

Hyphoderma gummosis, a disease causing wood decay, serious dieback, tree decline, and eventual death of citrus trees was first observed in 2000 in several orchards in Tulare, Ventura, San Luis Obispo, and Riverside Co. causing serious losses to some lemon growers (Marais et al., 2001a,b). Mainly older lemon orchards (between 35 and 50 years old) are affected.

2008 James Adaskaveg ( Biology and Management of Septoria)

Biology and Management of Septoria Spot of Citrus

Septoria spot of citrus caused by Septoria citri is a re-emerging disease of citrus in California. The disease occurs infrequently on fruit, leaves, and twigs and causes only superficial infections of fruit. Outbreaks have occurred sporadically over the decades since the first report in the 1940s.

2007 James E Adaskaveg (Biology & Management of Septoria)

Biology and Management of Septoria Spot of Citrus

Septoria spot of citrus caused by Septoria citri occurs mainly on mature, cold-injured fruit in rainy winter seasons. Due to recent outbreaks, Septoria spot has become a quarantine disease in some export countries for California citrus fruit. Fruit marketed to these destinations have to be certified as disease-free.