Posts Tagged: almonds
KARE scientist visits Australia to share insights into disease control and food safety strategies for tree nut crops.
Themis Michailides, plant pathologist and lecturer in the Department of Plant Pathology at UC Davis, and Kearney Agricultural Research and Extension Center, recently visited Australia, primarily to visit pistachio and almond orchards and discuss disease control and food safety strategies for these crops.
In 2011, Australia had excessive rains at harvest time, which resulted in pistachio crop losses of 40 to 50 percent due to anthracnose fungi. The lost crop was worth about $15 million. To help prevent the problem in the future, the growers went to California to get input on current disease management strategies. Themis Michailides’ research and extension program was very helpful. As a result, the pistachio and almond crop growers of Australia created protocols to prevent and control the disease. The Australian Pistachio Industry invited Dr. Michailides to tour the Riverland and Sunraysia regions this year to inspect orchards that were previously affected by the anthracnose as well as meet with Australian researchers.
Dr. Michailides was surprised to find lower limb dieback in Australia. This is a problem that his program studied in California for many years with funds from the Californian Almond Board.
The trip was mutually beneficial. The Australian industry and researchers received expert advice and Dr. Michailides learned about practices in Australia that can benefit his research and extension program in California.
Highlights of the trip are summarized below.
- Brisbane: met with Australian plant pathologists from the local area and discussed many plant diseases of interest to the local region.
- Adelaide: stayed and enjoyed visiting with his UC Davis classmate Prue McMichael’s family; visited local laboratories and research organizations to discuss pistachio, pomegranate and almond disease control and food safety strategies.
- Mallee and Riverland regions: met with growers and researchers to discuss disease control and food safety strategies for pistachios and almonds. Displayed samples of Anthracnose and Botryosphaeria infected nuts and leaves that were collected during Dr. Michailides’ Australian orchard visits.
- Mildura: met with the Australian Pistachio Research and Development Committee and discussed some of the pistachio disease control efficacy research being done in Australia. Recommended that the committee access “Fungicides, Bactericides, and Biologicals for deciduous Tree Fruit, Nut, Strawberry, and Vine Corps 2012” to review current pest management strategies for tree fruit, tree nut, strawberry and vine crops. Shared how to closely inspect trees, bark, wood, leaves and nuts to identify and diagnose symptoms of various diseases, as well as predict disease risks based on inoculum levels and weather conditions.
Dr. Themis Michailides inspecting pistachio trees in Australia for disease symptoms. (Photo courtesy of The Murray Pioneer Pty. Ltd.)
He sounded the alarm.
“We need 1.6 million colonies, or two colonies per acre, and California has only about 500,000 colonies that can be used for that purpose,” said Mussen in a news release we posted Feb. 8 on the Department of Entomology website. “We need to bring in a million more colonies but due to the winter losses, we may not have enough bees.”
Those winter losses--still being tabulated--and the resulting fewer bees per hive could spell trouble for almond growers, he said.
He said 2012 was a bad year for bee nutrition.
“Last year was not a good year for honey production in the United States,” Mussen said, “and it could be one of the worst honey production years in the history of nation, although it’s been pretty rough in some of the previous years. Usually when we’re short of nectar, we’re short on pollen, and honey bees need both. So, 2012 was a bad year for bee nutrition.”
The winter of 2012-2013, in general, was bad for bees. In fact, it's never been good since the winter of 2006 with the onset of colony collapse disorder, a mysterious malady characterized by adult bees abandoning the hive, leaving behind the queen bee, brood and food stores.
Bee scientists think CCD is caused by a multitude of factors, includes, pests, pesticides, parasites, diseases, malnutrition and stress. On the average, beekeepers report they're losing one-third of their bees a year.
“We don’t know how many more bees will be lost over the winter,” Mussen told us on Feb. 8. “We consider the winter ending when the weather warms up and the pollen is being brought into the hives.”
“Many, many colonies are not going to make it through the winter. We won’t have as large a bee population as in the past.”
Mussen, a member of the UC Davis Department of Entomology since 1976, knows honey bees. He is a honey bee guru, a global expert on bees. "Have a question about bees? Ask Eric Mussen." This month, especially, he is in great demand as a news source.
The New York Times quoted Mussen in its March 28th article, "Mystery Malady Kills More Bees, Heightening Worry on Farms."
Eric Mussen, an apiculturist at the University of California, Davis, said analysts had documented about 150 chemical residues in pollen and wax gathered from beehives.
"Where do you start?" Dr. Mussen said. "When you have all these chemicals at a sublethal leel how do they react with each other? What are the consequences?"
Experts say nobody knows.
Meanwhile, Mussen spent much of the day today granting news media interviews. On Tuesday, April 2, it will be for Dan Rather Reports: Buzzkill.
It was not so long ago that honey bees drew little attention, despite the fact that they pollinate about one-third of the food we eat. A three-letter acronym, CCD, changed all that.
Rich Schubert, a beekeeper in the Winters/Vacaville area, said it best during a question-and-answer session at Mussen's UC Davis Distinguished Seminar on Oct. 9, 2007.
If 5600 dead cows were found in a pasture, instead of 5600 dead bees, people would start paying attention, Schubert told the crowd.
So true. And now they are.
Honey bee foraging on almond blossom. (Photo by Kathy Keatley Garvey)
Close-up of honey bee on an almond blossom. (Photo by Kathy Keatley Garvey)
Symphony in the almond blossoms...
There's a wild almond tree planted in a field off Bee Biology Road at the University of California, Davis, that's incredibly beautiful.
Honey bees from the nearby apiary at the Harry H. Laidlaw Jr. Honey Bee Research Facility reunite on the blossoms, each bee seemingly vying for the best pollen to take back to her hive.
The tree is not quite in full bloom, but don't tell that to the bees. We captured a few images of them in flight, a moving symphony performance in the almonds.
Honey bee heading toward almonds blossoms on Bee Biology Road, UC Davis. (Photo by Kathy Keatley Garvey)
Honey bee, packing pollen, in mid-flight. (Photo by Kathy Keatley Garvey)
A blur of bee wings. (Photo by Kathy Keatley Garvey)
California almonds are on a roll. In the last 20 years, scientific discovery and grower ingenuity have nearly doubled almond per-acre productivity. A good yield in the 1980s was 1,400 pounds per acre. The average yield for 2011 was 2,670 pounds of shelled almonds per acre.
Forty years ago, California farmers produced less than 100 million pounds of almonds on about 200,000 acres of almond orchards. Mechanization, improved irrigation efficiency, advances in insect and disease management, pruning research and fertilization studies have fueled explosive growth in the industry. Farmers in California’s Central Valley now tend 760,000 acres of almond trees, producing about 2 billion pounds of shelled nuts a year. The crop, which represents 100 percent of U.S. almond production and 75 to 80 percent of world production, was valued in 2011 at $3.87 billion, surpassing table, wine and raisin grapes, which were valued at $3.86 billion.
“Even with this record production, we have more demand than we have supply,” said Bob Curtis of the Almond Board. “The driver behind that is nutrition studies that show almonds are a healthy food and snack.”
A tremendous amount of UC research is behind the California almond success story, said Bruce Lampinen, UC Cooperative Extension specialist in the Department of Plant Sciences at UC Davis, an expert in almond canopy management.
“Higher density plantings of almonds and a trend towards less pruning, and improved water management have led to much higher yields,” Lampinen said.
Many almond growers have replaced flood irrigation with micro-sprinkler or drip irrigation, said Larry Schwankl, UC Cooperative Extension specialist in the Department of Land, Air and Water Resources at UC Davis. Schwankl is based at the UC Kearney Agricultural Research and Extension Center in Parlier. These irrigation systems increase the precision of water and fertilizer application. Over the years, UC Cooperative Extension advisors and specialists established demonstrations of micro-sprinkler and drip systems in many parts of the Central Valley and reached out to farmers to show how they could be managed to optimize production.
“Twenty years ago, we simply guessed at the amount of water that the trees needed and we applied it on a calendar basis,” said Joe MacIlvaine, president of Paramount Farming Company in Kern County, one of the state’s largest growers of almonds, pistachios and pomegranates. “Today, we are delivering water and nutrients directly to the root zones when they are needed.”
Two decades ago, a granular form of nitrogen fertilizer was generally applied to almond orchards in the fall to allow winter rain and irrigation to move it into the soil for use by the trees in spring and early summer. Nitrogen use efficiency was believed to be about 40 percent. Now, nitrogen fertilizer is applied through the irrigation system during the growing season, when the tree needs it.
“Today, our nitrogen use efficiency can be as high as 85 percent,” said Blake Sanden, UCCE advisor in Kern County, an irrigation expert. He and Patrick Brown, professor in the Department of Plant Sciences at UC Davis, have conducted nitrogen trials in almonds with Paramount Farming.
“When you increase the conversion of applied nitrogen fertilizer to higher crop yield, there is significantly less potential for nitrogen to leach below the rootzone and contaminate groundwater,” Sanden said. “But each field is unique and requires site-specific management to achieve these high levels of efficiency.”
Another area where UC research has led to significant crop yield growth is in canopy management and tree spacing. Research by Mario Viveros, UCCE advisor emeritus in Kern County, and other scientists showed that a tendency among growers to over prune was taking a toll at harvest time.
“A lot of farmers who are now growing almonds had experience with fresh fruits, where you do need to prune to get light on the fruit for good color. In almonds more canopy generally means more yield,” Lampinen said. “Today, most almond growers only prune when branches are growing in the way of tractors or other equipment.”
UC research also found that orchards planted with traditional wide spacing between the trees weren’t making the most efficient use of sunlight on the farms. Older orchards had 60 to 70 trees per acre. Today, almond orchards are planted at an average density of about 110 trees per acre based on results of UC research.
However, studies have also shown that crowding still more trees into orchards triggers diminishing returns. In almond production, the nuts are shaken from the trees to dry on the ground before they are harvested.
“If the orchard floor becomes too shaded by trees planted too densely, the orchard floor temperature and humidity become optimal for growth of pathogens that could become a food safety problem,” Lampinen said. “You want enough sunlight to hit the orchard floor to reduce potential pathogens, like salmonella.”
MacIlvaine acknowledged the role of UC Cooperative Extension in helping the almond industry achieve the production milestone in 2011.
“The University of California has been a wonderful partner in improving our farming practices,” he said. “The whole system is not only more efficient, but more sustainable at the same time.”
Hear more of MacIlvaine's comments in the video posted below:
When you first see the leaffooted bug, you know immediately how it got its name.
The appendages on its feet look like leaves!
This morning we saw one in our catmint (Nepeta) patch. It crawled beneath the tiny leaves, sharing space with honey bees, European wool carder bees, butterflies and assorted spiders.
Tonight scores of them stormed our pomegranate tree. In fact, they made the immature fruit their kitchen, living room and bedroom.
Although the leaffooted bug (Leptoglossus clypealis) is a pest of pistachios and almonds, we've never seen it on our pomegranate tree until today. Our tree, planted in 1927--back when Herbert Hoover was the U.S. president--has few pests. One year white flies attacked it mercilessly. Tonight leaffooted bugs claimed squatters' rights.
The adult bug is about an inch long with a white or yellow zigzag across its back. Shades of Zorro! Its most distinctive feature, however, are the leaflike appendages on its feet.
Back in 2009, integrated pest management specialist Frank Zalom, professor of entomology at the University of California, Davis, co-authored UC IPM Pest Management Guidelines on the leaffooted bug as it pertains to almonds. Zalom and his colleagues called attention to their needlelike mouthparts. The adults feed on young nuts "before the shell hardens." And after the nut is developed, "leaffooted bug feeding can still cause black spots on the kernel or wrinkled, misshapen nutmeats."
As for our pomegranate tree, we're not sure how well these leaffooted bugs can probe the tough, leathery fruit.
We open the pomegranates with a serrated knife...
Close-up of leaffooted bug. (Photo by Kathy Keatley Garvey)
Leaffooted bugs making pomegranates their kitchen, living room and bedroom. (Photo by Kathy Keatley Garvey)
Beady eyes, colorful antennae and appendages on its feet that look like leaves. (Photo by Kathy Keatley Garvey)