Posts Tagged: Coachella

DESERT LEMON FRUIT DROP GROWER ROUND TABLE DISCUSSION

In the fall of 2015 and 2916, growers in the desert regions reported excessive fruit drop. Particularly in the Coachella Valley, Imperial County, and in Yuma, Arizona. The cause of the fruit drop is unknown. Come learn more about the current situation and find out how you can help resolve this issue.

SEPT. 12, 2017 – INDIO, CA

 Noon-1pm Ciro's Resturante & Pizza, 81963 CA- 111, Indio, CA 92201 Lunch will be provided

Lemon Growers in the desert regions are highly suggested to attend

Will be in attendance: Sonia Rios, UC Farm Advisor, Peggy Mauk, UC Specialist, Tracy Kahn, UCR Specialist,  Ben Faber, UC Farm Advisor and Alan Washburn

Please RSVP for this Free Event:

http://ucanr.edu/survey/survey.cfm?surveynu

If you have any questions, please contact Sonia Rios: sirios@ucanr.edu; 951-683-6491 Ext. 224

Case Study: Branch Canker and Hendersonula Diseases Troubling Growers in the Desert

In the fall of 2016 growers in the Coachella desert have been experience very puzzling symptoms on their grapefruit trees. One incident, symptoms the tree had gumming oozing from the branches (Fig. 1). Usually if it were oozing from the stump it would be a root disease such as Phytophthora spp. After photos and branch samples were taken to the Plant Pathologist at University of California, Riverside, Dr. Akif Eskelan, results determined that the trees had branch canker and Hendersonula Disease.

Symptomology

Infection by Nattrassia mangiferae (Hendersonula toruloidea) causes bark cracking and peeling or dead bark that remains tightly attached to dead limbs. Black, sooty growth may develop beneath infected bark. Brownish moist areas appear on limbs during the first stages of disease, then the bark in these areas cracks or peels away revealing black masses of fungal spores (Fig 4.). In advance stages, the injured limbs may “bleed” profusely, oozing a sap like sticky

 substances (fungal spores) (UC IPM 2017). Leaves on infected limbs suddenly wither, turn brown, and dry up. This may ad to the ends of the branches getting sunburned (Fig. 2). However most dead leaves typically remain attached to the twig. Black sooty spores that can survive for long periods under hot dry conditions are spread by wind or rain throughout the year. The disease, however, can only develop under warm temperatures growing best at 90^oF. The southwest side of the tree is the most likely place to find branch wilt because of a higher frequency of sunburn injury.

 

 

 

 

 

 

Management

Trees weakened by a disease, water stress, nutritional deficiencies, excessive pruning/mechanical damage create a are more susceptible. As many of these stressors can cause a tree to get sunburned and creates wounds that can serve as infection sites for this pathogen.  Prevent sunburn by maintaining vigorous canopies through best management practices http://fruitandnuteducation.ucdavis.edu/generaltopics/ .  Proper irrigation, fertilization, pruning, and pest control. Look for symptoms annually right after harvest while there are still healthy leaves on trees. Remove diseased limbs, cutting back to a lateral branch into healthy wood that shows no discoloration. Burn all infested wood, do not chip and use infected wood as mulch.

Additional Resources can be found at:

http://eskalenlab.ucr.edu/handouts/desertdieback.pdf

 

 

2017 Date Field Day: A Success!

The University of California Cooperative Extension (UCCE), UC Riverside, United States Department of Agriculture/Agriculture Research Service (USDA/ARS), and the California Date Commission hosted a Date Field Day on February 15, 2017 at the UC Riverside Coachella Valley Agricultural Research Station. It was a full house that day, with approximately 55 Growers, farm managers, and other date stakeholders. The field day included a field research plot tour, lunch, and Continuing Education hours where available for attendees.

 

Speakers included Tom Perring, UCR Professor of Entomology, who spoke about his Pink Hibiscus Mealybug biocontrol research. Pink Hibiscus mealybug is a new threat to the date industry. This insect has a host range of 200+ trees species. The first findings where on backyard tree species and has been spreading to agriculture commodities and has just recently has become an issue in dates. Perring is currently in the early stages of rearing a parasitoid that may be able to help reduce the mealybugs population.

Robert Krueger, Citrus and date researcher Riverside USDA/ARS spoke about nitrogen assessment of date palms. He discussed diagnostic sampling implications, which suggest that there are differences in concentrations of various elements that occur in different portions of the leaf, and at different aged leaves can show different results, and also different seasons may also effect results. Based on the research it is suggested that the best sampling strategy is near khalal stage from middle pinnae of intermediate aged leaves during the summer.

 

Tony Fortier, from Phoenix Agrotech spoke about tissue culture methods in date palms. Date palm tissue culture is a rapid clonal propagation (micropropagation) method, where a small piece (explant) of the desired mother plant is initiated under sterile conditions into an in vitro environment, such as a test tube or culture vessel. Under tissue culture conditions, cells of the explant undergo rapid multiplication, ultimately producing many young date palm plantlets, which are genetically identical to the desired mother palm. This method is currently being used in the industry.

Peggy Mauk, UCCE-UCR Subtropical Horticulture Specialist spoke about establishment of date palms: Tissue Culture vs Off-shoots.

Locally, field plantings are threatened by pests and diseases. Globally, field plantings are threatened by climatic changes, human expansion, and political unrest. Therefore, maintaining and securing genetic diversity for improved cultivation and pest & disease resistance is crucial. MaryLou Polek, from the USDA/ARS spoke about the Role of the USDA Germplasm Repository and the importance of the collection.

 

 Sonia Rios, UCCE Riverside/San Diego Counties Subtropical Horticulture Farm Advisor spoke about pest issues in date palm, more specifically about weevils . Date palms flourish in high summer temperatures and low humidity which creates a perfect breeding ground and living conditions for pest, especially for the Red palm weevil (Rhynchophorus ferrugineus) (RPW) and South American palm weevil (Rhynchophorus palmarum) (SAPW). The RPW is considered most destructive arthropod pest of palms world-wide. SAPW causes similar damage on smaller scale. Both larvae's can cause economic damage as they feed on palm near apical growing point causing damage, which weakness the tree, and eventually causes death. The SAPW has been eradicated, however the RPW has been slowly showing up in date species in California, threatening the date industry. (Weevil Photos: Mark Hoddle)

The California date industry is worth ~$68 million (NASS, 2015). In 2015, 43,600 tons of dates where harvested. Coachella Valley produces about 95% of the dates consumed in the US. Date palms flourish in high summer temperatures and low humidity climates, which permits their production to certain growing regions. There are many threats to this economically important commodity and the University of California Cooperative Extension and other agencies are committed to assure the date industry thrives locally and globally.  The planning committee looks forward to next year's event.

 

Date Palm Field Day

Date Palms were planted in the Coachella Valley of California, which is approximately two hours east of Los Angeles in the early 1890s. And now, plantings cover over 6,500 plus acres. These acres produce over 40 million pounds of our four primary varieties, which are the Deglet-Noor, the Medjool, the Barhi and the Zahidi.Date palms need plenty of ground water to drink, but high heat and arid weather to produce fruit. Therefore, date palms grow best in hot and arid climates.

Come learn about our date industry in California at the 2017 Date Palm Field Day

Time: 8:00 A.M – 3:00 P.M

Location: Coachella Valley Agricultural Research Station 86501 72nd Ave, Thermal, CA 92274

http://agops.ucr.edu/cvars/

$15.00/person

Registration link coming soon

(Online registration available on site day of for walk-ins – payment by Card only)

 

Agenda

8:00   Registration

8:20   Welcome – Sonia Rios, CE Advisor

8:30   Tom Perring, UCR - Pink Hibiscus Mealybug biocontrol

9:00   Robert Krueger, USDA/ARS - Nitrogen assessment of date palms  

9:30    Tony Fortier, Phoenix Agrotech - Tissue Culture date palms

10:00     Break

10:15   Peggy Mauk, UCR/CE - Establishment of date palms-Tissue Culture vs Off-shoots

10:45   MaryLou Polek, USDA/ARS -  Role of the USDA Germplasm Repository

11:15    TBD

11:45     Lunch

(Included in registration)

1:30    Field tours

If you have any questions contact: Sonia Rios, UC Farm advisor

sirios@ucanr.edu

951.683.6491 Ext. 224

 

 

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