Posts Tagged: Kris Tollerup
To control spider mites, many almond farmers have taken to routinely spraying their trees with a miticide in May. However, research by UC Integrated Pest Management advisor Kris Tollerup shows that the pesticide application could cause more harm than good.
“The preventative sprays do suppress spider mite populations, but there's no beneficial effect because the mites show up very late in the season and the population density remains well below an economic level,” Tollerup said. “A natural enemy, six-spotted thrips, will likely show up and suppress the mite population before any damage occurs.”
Tollerup recommends almond farmers monitor their orchards for spider mites and six-spotted thrips to determine whether treatment is necessary.
During the 2017 growing season, about 517,000 acres of almonds in California received a preventative miticide application in May; 93% were treated with the insecticide abamectin.
“This strategy runs counter to sustainable integrated pest management practices,” Tollerup said. “The sprays adversely impact spider mite natural enemies and are based on the calendar, not on the monitoring and economic thresholds that the UC Statewide IPM program has determined help reduce pesticide applications.”
The heavy reliance on abamectin has also caused some spider mites in the mid-San Joaquin Valley to become 16 times more resistant to the miticide than susceptible populations.
Tollerup worked with the Almond Board of California and a large grower in Kern County to compare the effectiveness of the preventative miticide spray with plots that were simply monitored for pests and natural enemies.
“Tollerup and other UCCE advisors have correctly identified the problem and spoken out both in public and private about not treating unless economic thresholds have been met,” said a pest control adviser working in Kern County. “Because of Tollerup's role, we have been able to collaborate with farmers to hold off on spring treatments at many ranches and only treat when warranted, which has essentially removed a spray treatment on a vast number of acres.”
Surveys conducted after the trial results were released showed that 80,000 acres of almonds were not treated with miticide sprays in May 2018 and May 2019. The change in strategy resulted in a savings to farmers of about $2.2 million in miticide and application costs.
Moreover, Tollerup calculated a subsequent reduction of 880,000 pounds of carbon dioxide emissions due to reduced use of diesel tractors and motor-driven application equipment associated with the miticide spray.
For more information on integrated pest management of spider mites, see the UC Integrated Pest Management website and IPM of spider mites on almond improves farm profitability and air quality.
Center director Jeff Dahlberg, who will be 108 years old in 2065, predicted in his letter that today's modern technology – smart phones and computers – will be ditched by then in favor of holographic demonstrations about new plants and agronomic practices.
“You'll be able to see, in 3-D, how plant systems function, how genes work, and what happens when you turn a gene off or on and the cascading effects of those actions,” Dahlberg predicted.
A time capsule containing the letters will be buried on May 26, exactly 50 years after the May 26, 1965, dedication of the sprawling research station near Parlier in the Central San Joaquin Valley. It will also contain a 20-foot-long banner with a timeline showing significant research accomplishments at Kearney. The banner will have signatures and messages from all the attendees at the 50th anniversary celebration on May 26, 2015.
Kearney is one of nine agricultural research and extension facilities UC Agriculture and Natural Resources maintains in California. The northernmost is on the Oregon border near Tulelake; the southernmost is in Holtville, a short drive from the border with Mexico. Centers are found in the Sierra foothills, in the North Coast and in suburban Southern California. Each center represents local conditions and focuses on crops and activities important in the area.
At the 330-acre UC Kearney Agricultural Research and Extension Center, scientists conduct research on a diversity of Central San Joaquin Valley crops, including grapes, stone fruit, almonds, pistachios, pomegranates, kiwi fruit, blueberries, alfalfa and more recently sorghum. Twenty Ph.D.-level scientists are based at the center, where they conduct research in pest control, new crop varieties, plant disease control and irrigation strategies.
A scientist who joined the staff in 2013, Kris Tollerup, UC ANR Cooperative Extension advisor with the UC Statewide Integrated Pest Management Program (IPM), will be looking for some answers from his successors.
“Growers and pest control advisors are reluctant to adopt new IPM practices until they are well proven,” Tollerup wrote. “I am curious, do you face the same challenge?”
Since Tollerup will be 105 when the time capsule is opened, his young children, who will be 54 and 58 in 2065, may have to collect the responses for him.
UC IPM advisor Pete Goodell, who with 34 years of service to UC ANR is approaching retirement, had sage advice for successors that might continue to be bombarded with modern conveniences.
“My advice,” Goodell wrote. “Get out of the office and get to the farm . . . Create and nourish human networks as well as virtual ones.”
Goodell tells his successors that, no matter the technological advances that are sure to come, knowledge transfer will always be based on personal contact and trust.
“Humans, even in your time, are high touch species who thrive on social interaction,” he said.
The other three letters going in the time capsule include these quotes:
“I assume that (nematodes) still will be around when you read this letter. At least this is something that I tell my students: ‘nematode problems will outlive us.'” – Andreas Westphal, UC ANR Cooperative Extension nematology specialist.
“Release of genetically modified mosquitoes carrying sex lethal genes has been approved on a relatively small scale in a few countries. I wonder if this method of control will be better perceived in the future and become the norm?” – Anthony Cornel, entomologist and director of the Mosquito Lab at Kearney.
“It will be interesting to see how the citrus industry adapts to the (Asian citrus psyllid/huanglongbing) situation. Growers are very creative people and I believe they will find a way.” – Beth Grafton-Cardwell, UC ANR Cooperative Extension entomology specialist.
Author: Jeannette Warnert