- Author: Irene Lavagi
In 1998, as part of a series of preliminary Citrus Research Board (CRB)-supported trials, navel orange trees treated with a dwarfing agent were planted at the Lindcove Research and Extension Research Center (LREC). The dwarfing agent used in these trials, a small RNA molecule named “Transmissible small nuclear Ribonucleic acid” (TsnRNA”) resulted in a dramatic reduction in tree size. Most importantly for citrus growers, fruit yield per canopy volume and fruit quality (size, color, sugar/acid ratio) of these TsnRNA-treated trees was not affected while double number of trees could be planted in the same land surface (up to 400 trees per acre).
Almost 20 years after planting, the threat of HLB brought about a renewed interest in this potential technology. When growers saw the dramatic reduction in size of these trees during a visit to LREC in November 2014, they expressed a strong desire to explore this technology.
Production of commercial dwarfed trees is key to the successful development of high-density plantings (potentially under protected screens – CUPS), which will be critical to meet future citrus production challenges. To assess the potential savings offered by the employment of this application, UC Riverside scientists are investigating nitrogen fertilizer requirements, nutrient uptake efficiency, water-use efficiency, pesticide application efficiency and savings in labor time for several horticultural operations such as hedging, spraying, fruit harvesting, and tree inspections.
Last winter, fruit nutrient analysis was performed so that fertilization efficiency can be determined. This spring, LREC staff brought several electrical outlets to the field so that equipment to monitor water uptake could be set up. UC Riverside scientists installed sap-flow sensors into the trunks of the dwarfed trees and connected them to dataloggers so that data on water use-efficiency can be calculated.
This CRB-supported project has also fostered the collaboration between the Microbiology and Plant Pathology Department and the Botany and Plant Sciences Department at UC Riverside. Dr. G. Vidalakis, Dr. I. Lavagi, and Dr. R. Christiano work with Dr. L. Santiago and Dr. C. Lovatt to determine the potential of this technology for the California citrus industry.
- Author: Therese Kapaun
- Editor: Beth Grafton-Cardwell
Annual CTV testing of all trees at the Lindcove Research and Extension Center was completed in April. Four hard-working field staff sampled 11,000 trees by blotting the cut ends of four stems per tree onto nitrocellulose membranes. Membranes were bulk processed with DAS-ELISA in the Lindcove Plant Pathology Lab. Samples found to contain the virus were further tested for strain type using RT-qPCR. Trees that were found to be positive will be removed to protect the research program and foundation trees at Lindcove.
Therese Kapaun, LREC Staff Research Associate, used TaqMan probes to determine that samples were infected with the T30 strain, which is the common asymptomatic strain in the Central Valley. Further, she tested all positive samples for presence of MCA13 reactivity, as trees can be co-infected with multiple strains. Fortunately all trees were negative for this epitope, as this is the strain that reveals potentially virulent isolates, which are found in low incidence in this area.
- Author: Elizabeth E Grafton-Cardwell
Hannah Kahl and Tobias Mueller, research staff for Dr. Bodil Cass and Dr. Jay Rosenheim in the Entomology Department of UC Davis are conducting experiments in the laboratory and orchards at Lindcove Research and Extension Center. The goal of the research is to determine if earwigs, katydids and citrus thrips cause significant damage to each of the commonly marketed groups of mandarins. If certain varieties are not susceptible to damage, this could greatly reduce pesticide treatments in those varieties. This work is being funded by the Citrus Research Board and the California Department of Pesticide Regulation.
- Author: Cheryl Reynolds
Spring is in full swing and summer is right around the corner. If you work in agricultural, turf, landscape, or structural settings, you are probably at your busiest. If you handle pesticides as part of your work, you most likely wear some sort of personal protective equipment (PPE). However, do you know if you are wearing the right type for the job that you do? Wearing the appropriate PPE, taking it off the right way, and correctly cleaning it prevents unnecessary pesticide exposure to yourself and others. Learn the steps so you don't expose your family members or those around you to pesticide residues by viewing a brand new online course on Proper Selection, Use, and Removal of Personal Protective Equipment from the UC Statewide IPM Program (UC IPM).
The course is approved by the California Department of Pesticide Regulation (DPR) for 1.5 hours in the Laws and Regulations category. This course is designed for all pesticide handlers with the goal to provide them with information on pesticide labels and the California Code of Regulations (CCR) to help them select, wear, remove, and dispose of or store PPE.
In California, all pesticide handlers (applicators, mixers, loaders, those who transport pesticides, or those who fix application equipment) are legally required to wear PPE. However, in order to get the most protection from PPE, it must be used correctly. Violations involving the incorrect use of PPE were the second most commonly reported type of agricultural-use violation in 2017 as reported by DPR (PDF).
The new PPE online course opens with a scenario describing a real example of an accident reported to DPR that led to an incident of pesticide exposure because the correct eye protection was not worn. The content that follows is divided into six instructional modules, highlighting types of PPE, how to select it, and when certain items should be worn. Answer short questions about the different types of PPE. Open pesticide labels to learn how to select the right PPE and learn when certain items should be worn. Short how-to videos and animated sequences demonstrate the proper way to put on or remove items such as gloves, coveralls, respirators, and eyewear. You must pass a final test with 70% or higher to receive your certificate of completion and continuing education hours.
If this is the year to renew your license with DPR, get a jumpstart on it. Take this new course and all the other UC IPM online courses to refresh your knowledge and get the CEUs you need. There is a $30 fee for taking Proper Selection, Use, and Removal of Personal Protective Equipment. You are welcome to view the content for free on YouTube, but without the activities, final exam, and continuing education credit. For more information about license renewal, visit DPR.
- Author: Elizabeth E Grafton-Cardwell
This weekend is the annual Lindcove REC Fruit Display and Tasting Event! (22963 Carson Ave., Exeter)
On Friday, Dec 8, we open from 9-noon for the citrus industry, with tours of various projects at the Center starting at 10 am. Dr. Georgios Vidalakis will provide a tour of the Citrus Clonal Protection Program, Dr. Tracy Kahn will tour the Demonstration orchard and Dr. Mikeal Roose will discuss the seedless citrus program and the new lemon variety trial. UCCE Farm Advisors Craig Kallsen and Greg Douhan will be available to answer questions.
On Saturday, Dec 9, we open from 9-noon for the general public and the high school FFA citrus judging teams to taste and enjoy more than 100 varieties of citrus. Master Gardeners from Tulare and Fresno will be assisting and providing answers to backyard horticultural questions. Take a bag of fruit home for $5. Choose from Cara Caras, Navels, Mandarins, or assorted citrus from bins located in front of the Conference Center.