Navel and Valencia Exports to Korea (NAVEK) Plans for 2010/11 Growing Season

Transcription

1 California Orange Industry Navel and Valencia Exports to Korea (NAVEK) Plans for 2010/11 Growing Season J. E. Adaskaveg University of California, Riverside H. Forster, D. Felts, L. Hou, J. Enns University of California, Davis and Riverside

2 Historical distribution of Septoria spot of citrus in California Septoria Spot of Citrus Symptoms and signs Septoria citri: a quarantine pathogen in some countries such as Korea. Over the past 6 years, strict requirements for certification of all fruit exported to Korea Pre- and postharvest fungicide treatments Forecasting the risk of infection based on temperature and rainfall Fruit sampling and disease detection NAVEK program

3 Septoria Spot of Citrus Current Trade Requirements As of July 2010 import requirements by Korea have been relaxed Key Points (Plant Quarantine Agreement): Septoria spot remains a quarantine pest in Korea Korean Inspectors will evaluate fruit for sporulation of the fungus on import fruit in Korea No incubation of fruit by NPQS No molecular (PCR) testing by NPQS Guidelines for Good Agricultural Practices to minimize the occurrence of Septoria spot need to be established as a voluntary program.

4 Septoria Spot of Citrus current trade requirements and research objectives As of July 2010 import requirements by Korea have been relaxed but the orange industry of California should use Good Agricultural Practices in growing orange fruit to avoid the potential re-implementation of a strict certification program - Growers should prevent S. citri infections. This includes application of preharvest fungicides. Risk assessments will continue to be made based on environmental conditions and Disease Forecasts made available to the industry. Packers and growers should continue to scout and sample for the disease for the disease. Submitting fruit samples to the NAVEK detection lab will be voluntary but should still be strategically used as an effective tool to avoid costly fruit rejections in Korea.

5 Risk Assessment Model for Forecasting Septoria Spot of Citrus Summary of Risk Assessment Model for Septoria Spot of Oranges in California Season Numerical Risk Model for forecasting Septoria Spot Precipitation (mm) Hrs with T< -1 C < > Assessment A Timing of Second Application (1st application Oct Nov. 30) Oct 15 to County Date Hrs <-1 Range Pp (mm) Pp Range RISK Fresno 4-Dec Tulare 4-Dec Kern 4-Dec Fresno 11-Dec Tulare 11-Dec Kern 11-Dec Fresno 18-Dec Tulare 18-Dec Kern 18-Dec Assessment - B Timing of Third Application (2nd application by Jan. 25) Jan. 13 to County Date Hrs <-1 Range Pp (mm) Pp Range RISK Fresno 11-Feb Tulare 11-Feb Kern 11-Feb Fresno 18-Feb Tulare 18-Feb Kern 18-Feb Fresno 25-Feb Tulare 25-Feb Kern 25-Feb '

6 Septoria Spot of Citrus Current Suggested Actions Good Agricultural Practices or GAPs have been developed from the previous Guidelines for the industry in managing Septoria spot in cooperation with industry, UC, and regulatory officials. Same practices followed but changes made from mandatory to voluntary GAPs for Septoria spot management and Color Symptom Guides for disease identification will be posted on the CCQC website. Fruit sample testing will be on a voluntary basis for growers and regulators (USDA-APHIS) to aid in the detection of Septoria spot (NAVEK program). Electronic forms will be available (KOR numbers no longer required) just lot identification Molecular testing (PCR) of fruit only on the export side i.e., in California before shipping

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8 The NAVEK program for detection of Septoria Spot of California Oranges 1. Samples received, labeled, and suspect symptoms excised 2. Samples are pre-screened for morphological evidence of Septoria citri 3. Samples are processed for DNA extraction and RT-PCR Advantages: A) Highly specific and fast B) Elimination of false negatives C) Reduced risk of lab contamination with PCR products

9 Septoria Spot of Citrus current trade requirements and NAVEK strategies As of July 2010 import requirements by Korea have been relaxed Lesions of Septoria spot, but no pycnidia (sporulating structures) of S. citri, are allowed to be present on imported fruit. The detection of the disease and any quarantine action taken is based on the presence of reproductive structures on fruit at the port of arrival. NAVEK Strategies: Evaluate the inhibition & anti-sporulation properties of pending or registered preand postharvest fungicides. Methods: Treat naturally infected or inoculated fruit with selected fungicides and evaluate for fungal sporulation. Evaluate inhibition and antisporulation activity in lab and field. 1 mm

10 Septoria Spot of Citrus Alternative treatments under development Multi-site fungicides for preharvest use: Micro-encapsulated coppers (e.g., Kocide 3000, GWN4620) EBDCs (e.g., maneb, mancozeb) DMDCs (e.g., ferbam, ziram) Chlorinated hydrocarbons (e.g., chlorothalonil) Single-site fungicides used alone or in pre-mixtures: QoI Fungicides (e.g., Azoxystrobin) 1. Abound - preharvest 2. Graduate A+ - postharvest Other new active ingredients such as difenoconazole alone or in combination (e.g., QoI and DMI fungicides - Quadris Top). - preharvest

11 Septoria Spot of Citrus Evaluate copper and non-copper alternatives Field trial -A 2009/10 Rate Late Fall Winter Spring No. Trt* Form. (400 gal/a) 11/20/2009 1/21/2010 Eval. (%)** LSD 1 Check a 2 Bravo Weather Stik 720SC 4.8 b 3 Bravo Weather Stik 720SC 5.7 b Quadris 2F Kocide % MCE b Zinc Oxide 35% MZE Lime 99% 5 Kentan 40DF b Zinc Oxide 35% MZE Lime 99% 6 GWN b Zinc Oxide 35% MZE * - All treatments received: ProGibb 40WDG - 24 g ai/a (mixed with each treatment) on 11/20/09. ** - Fruit were evaluated for Septoria spot in mid-march for the incidence of disease based on 26 fruit for each of four single-tree replications. Disease symptoms were validated using the NAVEK PCR detection system.

12 Septoria Spot of Citrus Alternative Treatments Potentially for Registration Preharvest registrations of multi-site materials Full registration for chlorothalonil (Bravo) for all citrus (oranges, lemons, etc.) has been planned with the approved IR-4 residue project in 2009 (status ongoing) Special Local Needs registration planned for ferbam (Ferbam) (orange only). A federal label exists in the U.S. MRLs exist for chlorothalonil and ferbam in Korea and Japan Postharvest registrations of single-site materials CODEX MRLs have been obtained in 2009 for the newly registered postharvest fungicides (azoxystrobin, fludioxonil, and pyrimethanil). Food Additive Tolerance (FAT) for fludioxonil pending in Japan for this season, whereas azoxystrobin is pending in 2012.

13 Funding NAVEK for the Growing Season Federal TASC Funding Request A proposal has been submitted to the Foreign Agricultural Service (FAS) to support this program and off-set costs to the orange industry of California