Below is information for exporters from the California Citrus Quality Council (CCQC) on how to comply with the China and Korea export protocols.
China
Earlier this week, CCQC advised the industry that the risk of Phytophthora infections is very high in all counties except for Imperial and Eastern Riverside Counties and that fungicide applications for Phytophthora brown rot should be made by Jan. 21. Given the high probability of Phytophthora infections, it will be very difficult to extend the Jan. 21 deadline. High rainfall has reduced copper levels by 80 to 100 percent and initiated numerous infection periods in the last 6 weeks from Nov. 30.
Also, the forecast for additional rain events over the next 10 days means that it could be difficult to make the needed applications using air-blast sprayers because grove conditions are so wet. CCQC has consulted with UC Riverside’s Dr. Jim Adaskaveg, and he is providing the following recommendations:
- Don’t wait for the weather to clear and orchards to dry out to attempt to make air-blast applications
- Make aerial applications using a helicopter as soon as possible. Helicopter applications are preferred to fixed wing applications, because air circulation created by rotors provides better coverage that is needed lower on the tree.
- Fungicide mixtures can be used such as a phosphonate fungicide (Prophyt, K-Phite, etc.) that is systemic and a persistent contact fungicide such as oxathiapiprolin (Orondis) or mandipropamid (Revus) to protect fruit over extended times. This will maximize the protection of fruit.
- Increase monitoring for brown rot and follow the protocol thresholds. The China protocol requires the following:
- For counties other than Tulare County, Phytophthora brown rot should be monitored in the canopy 20 in (50 cm) above the ground
- If there are less than or equal to five (5) diseased fruit per acre the lot can be shipped to China
- If there are six (6) or more diseased fruit per acre the lot should not be shipped to China
- For Tulare County,Phytophthora brown rot should be monitored in the canopy 20 in (50 cm) above the ground
- There is a zero threshold for any diseased fruit per acre
- Fruit for export to China should only be harvested higher than 20 in (50 cm) above the ground
- Don’t take chances shipping marginal fruit to China. China closed the market to all California citrus exports in 2013 because of Phytophthora brown rot interceptions on only nine containers.
- For counties other than Tulare County, Phytophthora brown rot should be monitored in the canopy 20 in (50 cm) above the ground
An additional advisory about Septoria control measures for Korea will be sent to the industry by the end of the week.
Korea
Growers should apply a second copper or approved alternative (Quadris Top, Luna Sensation, Priaxor) fungicide application to acreage destined for export to Korea in Tulare and W. Riverside (Level 2 or yellow – moderate risk); – Fresno, Madera, and Ventura (Level 3 or pink – high risk); and – Santa Barbara, and San Luis Obispo counties (Level 4 or red – highest risk) by Jan. 21, 2022. Citrus groves in Kern and San Diego Counties are at Level 1 (low risk – green), whereas eastern Riverside and Imperial counties are at level zero according the Septoria environmental model. Applications are generally called for when Level 3 (red) is reached but more rain is forecasted in the week and thus, growers in Tulare and W. Riverside Co. (currently Level 2) should plan to apply management treatments. High rainfall occurred in District 1, but temperatures below -1 did not accumulate. Therefore, the potential for ice mark injuries was low, but infections can still occur on other types of injuries. Additional rainfall in Tulare and W. Riverside counties of approximately 0.5 to 1 inch (12-25 mm) will change the risk to level 3.
GAPs, which include more detailed information on Septoria and Phytophthora management can be found on the CCQC website. An additional advisory will be made in the coming weeks if additional fungicide applications are needed for Septoria and Phytophthora brown rot.
China and Korea Acreage
If citrus groves are being managed jointly to meet the China and Korean protocols, then an application of copper or a copper alternative is needed to maintain eligibility for both export markets for the counties listed above under “China”. Fungicides list for Phytophthora brown can be mixed with fungicides listed for Septoria Spot.
Additional Information
Dr. J. E. Adaskaveg at UC Riverside is monitoring environmental conditions and is modeling disease risk for all citrus growing regions in the state. He is also monitoring 10-day forecasts and actual weather conditions to determine if additional applications are necessary in citrus growing counties/regions across the state in the coming weeks.
Please contact Jim Cranney, CCQO President by telephone at (530) 885-1894 or via e-mail at jcranney@ccqc.org if you have questions or need additional information.
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