- Author: Saoimanu Sope
Historically, date palms are grown along riverbeds or in areas with groundwater because they require an abundance of water to produce a good crop. Unlike lettuce or table grapes, date palms are deceptive in that they do not immediately wilt if underwatered. Eventually, however, the lack of water hurts yields and fruit quality.
The default for date growers is to apply excessive water, but doing so is neither economically nor environmentally sound. To help growers, Ali Montazar, UC Cooperative Extension irrigation and water management advisor for Imperial, Riverside and San Diego counties, has developed knowledge that enables growers in the region to establish irrigation guidelines they can use with confidence.
“Water issues in California's desert are very different than in the Central Valley,” said Montazar. “There is no groundwater to recharge so growers in the desert only have the Colorado River.”
Since 2019, Montazar has been focused on irrigation management for date palms in the Coachella Valley, the largest producer of dates in the United States. Montazar's research identifies how much water is needed for the crop and the best water delivery method according to location, soil type and conditions, and date cultivars.
“Dates require a lot of heat and light, which is why they do well in the desert. But they also need a fair amount of irrigation,” said Robert Krueger, a U.S. Department of Agriculture horticulturist and Montazar's co-author of a paper on date palm irrigation management.
Much of what we know about date palm production comes from the Middle East, which has a climate similar to the low desert of California. “That information is from many, many years ago though,” explained Montazar, whose research shows that drip irrigation cannot be the only form of irrigation for date palms.
“Ali is the first to really look at micro-sprinklers and flood irrigation for date palms,” said Krueger, adding that the other advantage of Montazar's research is that it prepares growers for production during times of reduced water supply.
Albert Keck, president of Hadley Date Gardens, Inc. and chairman of the California Date Commission, described Montazar's research efforts as “subtle yet incredible and profound,” adding that his findings not only benefit other farmers but also cities relying on water from the Colorado River.
Keck, one of the largest date growers in California, is well aware of how disruptive, expensive and time-consuming irrigation for date palms can be. Montazar has enabled growers like Keck to irrigate less without sacrificing yield or quality.
“Ali might save us a tiny percentage of the amount of water we're using. It might be a 5 or 10% savings. It doesn't seem like much, but it's an incremental improvement in efficiency,” said Keck. “And if you add all of these improvements up, say, along the U.S. Southwest, then that has a pretty profound impact.”
Montazar recommends that date growers in his region use a combination of drip and two to three flood irrigation events to manage salinity levels derived from the Colorado River. “We cannot maintain salinity issues over time if we're only relying on drip irrigation in date palms,” explained Montazar.
Flood irrigation pushes the salts below the root zone, when they would otherwise build up within the root zone preventing efficient water uptake. It also aids in refilling soil profiles quickly and more effectively since drip has a lower capacity of delivering sufficient water.
“Growers know what they need to water their crop within a broader parameter. But Ali has narrowed that window and helped us become more precise with our irrigation,” Keck said. “There's still room for improvement but we're spending less money, wasting less time and using less water now, and we're still getting the same positive results.”
Currently,Montazar is collaborating with the California Date Commission on developing guidelines for best irrigation management practices in the desert for date palms, which should be available by the end of 2023. These guidelines are based on a four-year data set from six monitoring stations and extensive soil and plant samples from commercial fields located in theCoachella Valley, Imperial Valley and near Yuma, Arizona. Additionally, Montazar is working to quantify how water conservation impacts growers economically.
“Growers from United Arab Emirates, Egypt, Tunisia and Mexico have already reached out asking for this information,” Montazar said, while reflecting on a presentation he made to a group of international date growers in Mexico late last year.
To read the paper on date palm irrigation, published in MDPI's Water journal, visit: https://www.mdpi.com/2073-4441/12/8/2253.
- Author: Ben Faber
2019 Date Palm Field Day
November 21, 2019
8:30 - 2:15 PM
Coachella Valley Agricultural Research Station
86501 72nd Ave, Thermal, CA 92274
Fee: $25, lunch included
Agenda
8:00am – Registration for CE units, coffee, pastries
8:30am- Welcome- Sonia Rios, UCCE Riverside
8:45am- Tom Perring, UC Riverside. Current status of Insect and Mite Pests of dates
9:15am- Tom Perring, UC Riverside. Part 1: What we know about puffy skin of medjool dates
9:30am- Robert Krueger, USDA/ARS. Part 2: What we know about puffy skin of medjool dates/Date research pollination update
9:45- Ali Montazar, UCCE. An update on the on-going irrigation management project in California date palm
10:15am-Break
10:35- Mark Hoddle, UCR. Updates on the South American Palm Weevil Invasion
11:35- MaryLou Polek, USDA/ARS. Update on Date Palm Activities at the Repository
12:05pm- Lunch- Sponsored by Corteva
1:15pm- Peggy Mauk, UC Riverside.
1:45 - Bob Mulherin, Riverside Agriculture Commission. Laws and Regulation Updates
2:15 – Wrap up
Space is Limited-Register online at:
http://ucanr.edu/survey/survey.cfm?surveynumber=28232
*No Cash/Check payment will be excepted on site, day of
DPR/ISA Continuing Education Credits Upon Request
- Author: Ben Faber
What a great find and it was there all along, just like a used book store can be a gold mine at times.
http://www.avocadosource.com/papers/research_articles/ebelingwalter1959b.pdf
This is the section of Subtropical Fruit Pests by Walter Ebeling that covers avocado pests in not only California, but what was and is known to exist in other avocado growing regions around the US and the world. It was reproduced at the Hoshi Foundation's Avocadosource website. At this point it only contains the chapters pertaining to avocado. Other chapters in the full text cover citrus, grape, walnut, almond pecan, olive, fig, date and other "Minor Subtropical Fruits". The beauty of the book is not only historical, but that it is still current (although the DDT recommendations are out of date) for many pests. It also chronicles pests that have appeared in the past, disappeared and then reappeared. An example is Avocado Bud Mite - here, gone, here and seemingly gone again, probably to reappear sometime in the future. This is no replacement for the UC-IPM website, http://ipm.ucanr.edu/PMG/crops-agriculture.html , but it is a good look at how the pest has been managed in the past and is done so currently.
I thought I had the only copy of this book in Ventura County, but you could too. There are some listed on ABE Books for cheap.
This pestiferous book was compiled by Walter Ebeling at UC Riverside/Los Angeles. He was of some note, considered the Father of Urban Entomology. As you can see from the descriptions of avocado pests, he was a good all round entomologist, as well. Urban entomology really forces you to know a lot because of the diversity of arthropods in urban settings. He passed in 2010 and was recognized world-wide for his work.
IN MEMORIAM
WALTER EBELING
Professor Emeritus of Entomology
UC Riverside
November 26, 1907 – December 17, 2010
Walter Ebeling, world-renowned entomologist and pioneer in the field of Urban Entomology, died 17 December 2010 in a care facility in Bandon, Oregon at the age of 103. "Professor Ebeling was a legendary research entomologist," said Dr. Michael Rust, Professor of Entomology at the University of California, Riverside, who replaced Dr. Ebeling upon his retirement in 1975. "He had tremendous abilities, tireless energy, and a passion for science. He was an expert in so many fields of entomology including agriculture, physiology, and insect behavior. Dr. Ebeling helped develop Urban Entomology into a respected independent area of research."
Read more of his Memoriam: http://senate.ucr.edu/agenda/120221/IN%20MEMORIAM-Walter%20Ebeling.pdf
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[From the August 2016 issue of the UC IPM Green Bulletin]
The South American palm weevil (SAPW), Rhynchophorus palmarum, was recently discovered in a Canary Island date palm in San Ysidro, southern San Diego County.
Twenty additional Canary Island date palms in the San Ysidro area appear to be infested, but have not yet been confirmed.
Weevil Biology
The biology of SAPW is similar to the red palm weevil that was eradicated from Laguna Beach, Orange County, between 2010–2012.
The SAPW, native to Mexico and Central and South America, destroys the apical growth of the palm by feeding on the growing tissue in the palm crown, eventually killing the palm (Figure 3). This differs from the symptoms of fusarium wilt which causes dying of lower branches.
Symptoms and Signs
Signs of the pest include accumulated frass (insect excrement) at the base of the leaves and pupal cases on the ground near the tree. Holes and tunneling can also be found at the base of palm fronds.
In addition to Canary Island date palms, the South American palm weevil is also known to attack coconut palms, date palms, and the king sago palm in the cycad family.
It is believed that the spread of this pest can be delayed with the fast detection and removal of infested trees. Chipping (Figure 4), burning, and burying infested material deeply can reduce the likelihood that SAPW will emerge and escape from infested palms.
Report a Find
-Jennifer Pelham, UCCE Area Environmental
Horticulture Advisor UCCE San Diego & Orange counties,
jlpelham@ucanr.edu;
-Tracy Ellis, Agricultural Entomologist, County of San Diego, Tracy.Ellis@sdcounty.ca.gov
/h2>/h2>/h2>/span>- Author: Brad Hanson, UC ANR Weed Specialist
Here is an updated guide for herbicides that are registered for citrus, avocado and a few other tree crops.