As biopesticides become more available to the grape industry, growers and PCAs may wonder how to best go about incorporating them in the integrated pest management programs. This was a topic addressed by Dan Rodrigues from Vina Quest and the Cal Poly Viticulture & Enology Department at Malcolm Media’s recent Central Coast Grape Expo. Watch his brief interview here and read more about it in American Vineyard Magazine.
Stakes at All-Time High for Backyard & Commercial Trees in 2019
Detections of Huanglongbing (HLB), an incurable plant disease that kills citrus trees, increased by 160 percent in 2018 compared to the previous year, signaling the growing threat to the state’s iconic citrus trees, landscape and economy.
HLB is spread by a small pest called the Asian citrus psyllid as it feeds on citrus tree leaves. The disease is not dangerous to humans or pets, but it is fatal for citrus trees and has no cure. Once a tree is confirmed with the disease, it must be removed from the property in order to protect neighboring citrus trees.
The disease was first discovered in California in 2012 in Hacienda Heights. HLB was detected in 269 trees in 2017 and 699 trees in 2018, with a majority of these occurring in Los Angeles and Orange counties. The disease has not yet been detected in a California commercial grove.
HLB has devastated commercial citrus production in Florida. Over the course of 10 years, Florida’s commercial citrus industry lost $7.8 billion in revenue, 162,200 citrus acres and more than 7,500 jobs due to HLB. Should the disease spread from backyard trees in Southern California to nearby commercial citrus groves, the livelihood of California’s citrus production could impact about 3,900 farmers and 292,000 acres of citrus production in the state. Commercially grown citrus contributes $7 billion in economic impact to the state and employs more than 22,000 individuals.
“The livelihood of California’s commercial citrus industry and the generations of families it supports is at risk because of HLB,” said Jim Gorden, a citrus grower in the San Joaquin Valley and chair of the Citrus Pest & Disease Prevention Committee. “We are at a crossroads, and we must all work together to do what is necessary to protect our citrus.”
The California Department of Food and Agriculture (CDFA) has established quarantines throughout the state that limit the transport of citrus across state and international lines, and between areas where the psyllid and disease have been found. Additionally, CDFA has agriculture crews canvasing the state to inspect backyard citrus trees for the Asian citrus psyllid and HLB.
“The Department is committed to our partnership with California’s commercial citrus industry and residential citrus growers to fight HLB,” said Victoria Hornbaker, interim director of the citrus program at CDFA. “With more than half of California residences estimated to have a citrus tree on their property, and California citrus production supporting billions of dollars in our state’s economy, we all play an instrumental role in protecting our citrus.”
California residents play an important role in protecting the state’s citrus trees. Residents should: 
More information and photos of Asian citrus psyllids and HLB symptoms are available at CaliforniaCitrusThreat.org.
Once confined mostly to the Great Plains of North America, coyotes have spread across much of the continent, and can be a real threat and nuisance to farming communities. Check out this brief interview with USDA Wildlife Specialist Derek Milsaps, as he offers some recommendations on how to identify and deal with these pests. Read more about it in the coming issue of Pacific Nut Producer Magazine. Don’t currently receive it, subscribe for FREE Here.
Rodents of unusual size —California has got them! The new kid on the block is Nutria, a semiaquatic rodent, that has invaded California’s waterways, and is doing a lot of damage. USDA is asking farmers for help in locating these pests to be removed. Derek Milsaps from USDA-APHIS presented some information on this pest at the Tree & Vine Expo in Turlock recently. Watch his brief interview from the expo, and read more about it in the coming issue of Pacific Nut Producer Magazine. Don’t currently receive the magazine? Subscribe FREE today at: https://malcolmmedia.com/pacific-nut-producer-magazine-subscriptions/
Biosolarization Shows Promise for Conventional & Organic Farmers
By Diane Nelson
Farmers spend a lot of time and money controlling weeds and other pests, and often have to turn to chemical fumigants to keep the most destructive pests at bay. Farmers also wrestle with what to do with low-value byproducts of crop production, such as skin, seeds and hulls from fruit, vegetable and nut processing.
What if those agricultural waste streams could generate alternatives to chemical fumigants and make farming more productive, profitable and environmentally friendly?
Maybe they can. Researchers at the University of California, Davis, are encouraged by early results from collaborative experiments with “biosolarization,” a process that combines the sun’s heat with soil amendments to manage weeds and other soil-borne pests.
“It looks promising,” said food science and technology professor Christopher Simmons, who is testing biosolarization with various crops and working with farmers throughout the state. “We still have a lot of work to do, but biosolarization is showing real potential as a safe, sustainable way to control pests while improving crop quality and yield.”
Strengthening solar power
Many backyard gardeners know the power of solarization. When you lay a clear plastic tarp over moist soil, you can trap solar radiation and heat the soil enough to kill weeds and other soil-borne pests. It’s effective, but can take four to six weeks, which is often too long for commercial fields to lay fallow.
Biosolarization can accelerate and improve the process. Simmons and his team are adding organic amendments such as grape and tomato skins or ground nut hulls to the soil before they tarp it, which promotes growth of beneficial bacteria. The helpful microorganisms compete with pests and temporarily make the soil more acidic and therefore less hospitable to weeds and other pests.
Together, the soil-heating and microbial activity can reduce the treatment time to days, not weeks.
“And by activating beneficial microbes in the soil, biosolarization has the potential to improve soil health over the long term,” Simmons explained.
Testing under commercial conditions
Chemical fumigants are expensive, and many have been identified as carcinogenic by state and federal regulatory agencies. But when it comes to killing soil-borne pests, they are very effective.
“Fumigants are broadly biocidal, meaning they affect beneficial microorganisms along with the pests,” Simmons said. “Biosolarization allows more innocuous and beneficial microorganisms to persist in the soil.”
But for farmers to adopt biosolarization as an alternative to chemical fumigants, the treatment must be effective, predictable and economical. So the team is testing biosolarization with a wide variety of crops, amendments and soils against different pests in various locations at commercial scale throughout the state.
“We have field trials underway with lettuce, tomatoes, melons and various cover crops,” Simmons said. “And we have a long-term, 10-acre trial with almonds at a conventional orchard in Chico.”
In Chico, Simmons and his team are collaborating with almond grower Rory Crowley at Nicolaus Nut Company with funding support from the Almond Board of California and the Western Center for Agricultural Health and Safety. They are one year into a 25-year experiment to see if almond-processing residues and the sun can boost soil health and reduce weeds and other soil-borne pests. So far, Crowley is impressed.
“It’s been great for the soil,” Crowley said. “Using biosolarization and a mustard cover crop, we’ve increased organic matter by 1.25 to 1.75 percent, which is a huge jump. That’s good for carbon sequestration and the overall health of the soil.”
It’s too soon to tell if the soil improvements will translate to greater crop yield, but Crowley thinks biosolarization could become a good pest-management tool and a valuable use for what would otherwise be agricultural waste.
“We need to find a home for the co-products of almond processing, so why not see if we can use them to improve soil health while controlling pests?” Crowley asks.
Field tests continue
Simmons and his team are testing biosolarization on several annual and cover crops in plots on the UC Davis campus using agricultural waste streams from tomato and wine processing. Soon they will begin tests with strawberries, which are commonly treated with fumigants each season as farmers plant berries anew.
Simmons’ hope is to demonstrate to farmers that biosolarization can be effective and economical under a wide range of conditions against a broad number of pests.
“We’re making significant ground,” he said. “We’re hopeful biosolarization can help farmers return food and agricultural waste back into the system to control pests and improve crop production.”
To date, the deadly citrus greening disease Huanglongbing or HLB has not been found in California’s commercial citrus orchards; however, it’s only a matter of time. HLB strikes continue to be detected in residential areas, and its vector has spread all over the state. Watch this brief interview with Victoria Hornbaker, head of the CDFA’s statewide citrus program, as she shares the current status of the spread of HLB and its vector the Asian citrus psyllid, and CDFA’s eradication efforts. Read more about it in California Fresh Fruit Magazine. Don’t currently receive California Fresh Fruit Magazine? Subscribe for free at https://malcolmmedia.com/california-fresh-fruit-subscriptions/.
Malcolm Media’s Tree & Vine Expo was once again a big hit for growers & crop consultants looking to get a better grip on pest management in their orchards. One of the seminars featured UC IPM Advisor Jhalendra Rijal who shared how to more effectively incorporate mating disruption in their navel orangeworm control programs. Watch his brief interview and read more about it in Pacific Nut Producer Magazine. Don’t currently receive the magazine? Subscribe for free at: https://malcolmmedia.com/pacific-nut-producer-magazine-subscriptions/.
The posting of this video is a little belated as almond harvest has already begun, but if you’ve had hull rot issues this season, be sure to watch this brief video interview with Nut Crops Advisor Mae Culumber as she provides some tips to prevent hull rot and trunk damage through better irrigation practices, as explained at a mid-July Nut & Vine Irrigation seminar at the UC Cooperative Extension office in Fresno. Read more about it in Pacific Nut Producer Magazine. Culumber will also be addressing almond growers at the Annual Grape, Nut & Tree Fruit Expo coming up on November 13th at the Big Fresno Fairgrounds, so be sure to attend!
Pocket gophers can be very detrimental for growers, especially those with young orchards. So how do you minimize populations of these pesky critters? Watch this brief interview with Julie Finzel from the UC Cooperative Extension as she offers growers three quick tips for effective management. Julie will also be addressing growers on wildlife issues at the upcoming Grape, Nut & Tree Fruit Expo at the BIG Fresno Fairgrounds on November 13th, so be sure to attend. Learn more about it on AgExpo.biz.
Farmers are used to dealing with insect pest and small furry rodents, but how about wild pigs? Now, this is a more common issue in some areas more than others; nonetheless, pigs can wreak a lot of havoc in vineyards, orchards and field crops, so exploring your management options is key. Watch this brief interview with Julie Finzel from the UC Cooperative Extension as she provides some recommendations for growers.