- Author: Sandipa Gautam
California red scale season has started in the SJV
Sandipa Gautam - Citrus IPM Advisor
Based on traps placed at LREC citrus blocks, California red scale season began with Biofix on March 10. Pest Control Advisors in Kern, Tulare, and Fresno County reported that they have seen activity in the week of March 10.
Figure 1. California red scale male. Note: feathery antennae and brown band through the waist.
What is CRS Biofix?
CRS Biofix is the start of California red scale activity for this season. As weather warms up and heat units are accumulated above the lower developmental threshold of this insects, overwintering females start producing crawlers which develop. Males' complete development and fly to find third instar females to mate. Mated females then produce crawlers which is the First Generation of Crawlers, observed 550-degree days after the biofix.
What do males on the trap cards mean for management?
Pest control advisors have long used pheromone cards to monitor males and degree days to predict successive life event (crawler emergence) for timely management of CRS. Trap numbers may be different depending on the management choice.
Figure 2. Trap with pheromone placed within an arm's length inside the tree canopy. For assessment, count number of males within square box and multiply by 5.
- IGRs and Mating Disruption – few male scales may be on the cards as these two options affect males more than it does females. You may have lower males on card but have high CRS populations.
- Aphytis and Movento – Aphytis targets third instar females, thus affecting females more than it does males. Also, Movento controls CRS on twigs but not on wood. If Aphytis or Movento or both are used, you may see higher male numbers. If Movento was used, check the inner canopy branches, top of the tree for CRS patches.
Citrus entomology group will monitor degree days for four counties and update it biweekly on ucanr website https://lrec.ucanr.edu/Citrus_IPM/Degree_Days/.
Management is targeted at 1st and 2nd generations as the crawlers are emerging. Based on previous years, first generation crawler emergence occurs around 2nd/3rd week of May. As the degree day accumulation is temperature dependent, monitoring is critical to predict accurately.
Stay tuned for updates.
- Author: Ben Faber
Microirrigation for Crop Production: Design, Operation, and Management, Second Edition is the latest release in this go-to foundational resource for the basics of engineering and the science of the design and operation of micoirrigation systems. This new edition includes novel methods for measurement and estimation of evapotranspiration, resource-efficient microirrigation design and operation, advanced irrigation scheduling methods and tools, novel methods and technology of microirrigation automation, monitoring and control, updates in crop salinity tolerance and leaching practices, variable rate irrigation, updates on the use of biological effluents and chemicals and pesticides to include safety and regulatory concerns.The revised book provides an understanding on the basic science needed to comprehend systems design, operation, management, maintenance, monitoring and performance evaluation.
Editors: James E. Ayars, Daniele Zaccaria, Khaled M. Bali
- Author: Ben Faber
Invasive Fruit Flies
California is currently experiencing an unusually high?number?of invasive fruit fly?detections, resulting in quarantines being established across numerous California counties, including Ventura County. These invasive fruit fly species – including Mediterranean fruit fly, Oriental fruit fly, Queensland fruit fly and tau fruit fly – are considered not established in California. The California Department of Food and Agriculture (CDFA), in cooperation with the United States Department of Agriculture (USDA) and various County Agricultural Commissioners, has initiated local regulatory measures to eradicate and prevent the further spread of these fruit fly species statewide.
Resources:
- CAFruitFly.com
- Invasive Fruit Fly - Guide for Growers [NEW]
- Fruit Fly Quarantine Boundaries and Maps
- Frequently Asked Questions from Industry Members
- Harvest and Crop Movement Requirements for Growers
- Oriental Fruit Fly (Over 300 crops impacted)
- Mediterranean Fruit Fly
- Queensland Fruit Fly
- Tau Fruit Fly
- Residential Treatment Information and Maps (Conducted by CDFA)
While CDFA, USDA and our local County Agricultural Commissioners will be working to educate residents on the issue in the various quarantine areas, we ask you to please encourage nearby residents to avoid moving any homegrown produce from their properties and to cooperate with agriculture officials working in their area.
CDFA Photo: Oriental Fruit Flies
- Author: Ben Faber
International Research Conference on HLB
Here in California
The International Research Conference on Huanglongbing VII (IRCHLB VII) is just around the corner! The California citrus industry is excited to welcome researchers, regulators, and citrus industry members from around the world to the Golden State. Do not miss these key dates:
- Registration Deadline: Friday, March 15, 2024
A hotel room block with special conference rates has been set aside near the convention center and is filling up quickly. Book your room today at the Historic Mission Inn Hotel & Spa.
For the conference agenda, please click here. To register and access more conference details, CLICK HERE..
This Conference has occurred every two years (except for the covid period). Check out the Proceedings from previous conferences!
The proceedings of the “International Research Conference on Huanglongbing” are available from the 2008, 2011, 2013, 2015, 2017, and 2019 conferences. Please use the following hyperlinks to access the proceedings.
- Author: Ben Faber
Although, it's probably too late for the fungicide to correct Citrus Brown Rot
and Septoria on coastal lemons.
In normal rainfall years, a skirt spray of copper is done to prevent rain splash bringing spores of various Phytophthora species in contact with fruit. The spray is done the fall especially if high rainfall is expected that year, and can be reapplied in January/February if indeed rain has arrived. The spray is usually only up about 4 feet from the ground, rarely needed above that. But this year, there has been lots of wind and brown rot has appeared throughout tree. There has been lots of wind to spread the spores and create disease in fruit quite above ground level. Fruit on these trees is going to need to be selectively picked to avoid the infected fruit, adding to harvest costs.
https://ipm.ucanr.edu/agriculture/citrus/brown-rot/
Septoria is less common than brown rot along the coast where a skirt spray is or used to be normal practice. This was before the drought and low lemon prices made the practice less common. In the case of septoria, a whole tree copper spray is recommended in the fall. The disease, although not unseen, is not common, so most growers would apply only a copper skirt spray for brown rot. With this 2023/2024 rain year, the disease has showed up in many orchards, and of course, it is above the brown rot spray line in the canopy.
https://ipm.ucanr.edu/agriculture/citrus/septoria-spot/
Both of these diseases are going to cause problems for growers, because once in the fruit, it's not treatable or salable.