- Author: Elizabeth E Grafton-Cardwell
Each year, with funding provided by the California Citrus Nursery Board, we test every tree at Lindcove for citrus tristeza virus (CTV), a disease that is spread by aphids. While the infected trees are symptomless, we remove them so that infections do not affect the research results of the various trials being conducted at LREC. For many years, the average number of trees removed was 3 per year. In 2007 and 2008 we had a sudden increase in the number of infected trees (52 and 83 infected trees removed in those two years) because of the increasing incidence of CTV in the commercial orchards surrounding LREC. We recognized that removing this many trees each year would soon wreck havoc on the research trials and we requested assistance from the Tulare County Pest Control District. They responded to the need for reducing the rate of spread of CTV onto LREC, by voting to provide funding to treat for aphids every spring and fall in a 2 mile radius around LREC. The other San Joaquin Valley pest control districts have added a portion of their funding to the treatment program as well. We are pleased to report that the incidence of CTV at LREC has been declining since the aphid treatment program was started in 2008 to: 52 trees (2009), 20 trees (2010) and 12 trees (2011). Aphid control is reducing the spread of CTV, which is reducing the number of CTV-infected trees and so sustaining the excellent research program at LREC.
- Posted By: Elizabeth E Grafton-Cardwell
- Written by: William Chueng and Therese Kapaun
Dr. William Cheung is conducting tests at Lindcove REC to profile the response of a Washington navel orange tree infected with citrus tristeza virus (CTV) compared to an uninfected tree. A mobile sensor employing differential mobility spectrometry (DMS) records and analyzes the biogenic volatile organic compound (BVOC) signature emitted from the infected and noninfected plants. The DMS BVOC analysis is designed to be an initial screening tool for rapid sampling of pathogens in citrus. Studies are also underway in Florida to determine the citrus plant response to the bacterium Candidatus Liberibacter spp., the causal agent of the Huanglongbing disease (HLB). Dr. Cheung is working in Professor Cristina Davis’ group (Dept. of Mechanical and Aerospace Engineering, UC Davis) in collaboration with Professor Abhaya Dandekar (Dept. of Plant Sciences, UC Davis) and Professor Oliver Fiehn, (Genomic Core, UC Davis).
- Author: Elizabeth E Grafton-Cardwell
With University of California funding, we replaced the refrigeration units in the walk-in cold storage rooms in the packline facility at Lindcove. This will help us regulate the temperature better in these rooms and allow new and interesting experiments to be conducted at LREC.
- Author: Elizabeth E Grafton-Cardwell
Volatile organic compounds react with NOx to produce ozone which is an air pollutant affecting human health and plant growth. Silvano Fares, John Karlik and Allen Goldstein (shown left to right below), provided an imformative 'Featured research seminar' at Lindcove in May 11 to explain the results of their research, which suggests that citrus helps to reduce ozone.
- Author: Elizabeth E Grafton-Cardwell
The benches in the entomology greenhouse at LREC are being renovated in order to better support potted citrus. Seedlings are grown in this house and used for experiments to test the effects of insecticides on citrus leafminer. These plants are also used to determine if pheromone disruption can prevent mating, egg laying and plant damage by the leafminer larvae.