- Author: Mary Louise Flint
- Editor: Melissa G. Womack
Dear Master Gardeners,
I was hired to create Integrated Pest Management (IPM) programs for agriculture, but my interest in Master Gardeners started early. I remember attending the California State Fair in the early 1980's and being somewhat horrified to find the UC Master Gardeners answering questions using the Ortho Problem Solver and the Rodale Guide to Organic Gardening. I was told that they relied on these books because UC provided very little garden pest management information. This motivated me to write Pests of the Garden and Small Farm and later to hire Steve Dreistadt to compile Pests of Landscape Trees and Shrubs. From there we moved on to the Pest Notes, Quick Tips, UC IPM web site, UC IPM kiosk, our YouTube channel, blog and Twitter. Master Gardeners embraced and promoted all these products and now UCIPM is as well known for its home and garden information as for agricultural IPM.
I have loved teaching Master Gardener volunteers. They are the most enthusiastic students ever. I learn something every single time I go out and teach a class—and I've taught thousands of them. UC Master Gardeners inspire so much of what we do.
For example, it was Master Gardeners who stimulated our research on convergent lady
beetle releases for aphid control. All the published literature said releases weren't useful, but Master Gardeners challenged this idea. Over a 3-year study, Steve Dreistadt and I found that they were right, and we published several journal articles documenting the results.
Last but not least, thank you to all of you Master Gardener Coordinators. Each of you does an incredible job gently guiding and informing your enthusiastic volunteers. I have watched you in action and you do something special every day.
- Author: Jodi Azulai, UC Statewide IPM Program
Summer is upon us, and nothing quite says summer more than eating freshly picked blueberries or using them in delicious desserts. California blueberry growers can find an additional treat - the newly published UC IPM Pest Management Guidelines for blueberry on the UC IPM web site. California is quickly becoming a top producer of blueberries, and the new guidelines can help with management information on blueberry pests such as thrips, light brown apple moth, and spotted wing drosophila with additional information on pesticides and resistance.
In 1995 the University of California Small Farms Program and cooperating farmers started evaluating low-chill southern highbush varieties in San Luis Obispo and Ventura counties. They found that “low-chill” southern highbush varieties offered the most promise for extended season production on the central coast. By 1997, Kearney Agricultural Center trials found that southern highbush cultivars were also well adapted to the semiarid climate of the San Joaquin Valley. Further evaluations identified the best yielding and flavorful cultivars. Initial and ongoing UC Small Farms studies have escalated California blueberry production swiftly up the learning curve, providing California farmers of small to moderate operations a niche in a very competitive market.
- Author: Mary Louise Flint
When people move wood from place to place, they may also be moving invasive insects and diseases that threaten California's landscape and wildland trees. The goldspotted oak borer, which is devastating native oaks in San Diego, was likely brought there from Arizona in firewood. The polyphagous shothole borer, walnut twig beetle and thousand cankers disease, and the pathogen causing sudden oak disease, all continue to spread to new areas on infested wood chips, plant debris, or wood moved for woodworking or firewood.
Over the past year, the California Firewood Task Force has asked the public to "buy it where you burn it"—that is, don't bring wood from home when you camp, do use wood from local sources, and leave leftover wood at the campsite for the next camper. Even if wood does not appear to have borer holes or other evidence of pests, don't assume that the wood is pest free. Be on the safe side and don't move it.
The California Forest Pest Council established the Task Force in 2011 to educate Californians about what they can do to prevent movement of invasive pests in wood. The Task Force developed a Web site, put up billboards across California, sponsored children's activities at parks and fairs, encouraged campgrounds to sell only local firewood, gave presentations across the state, and developed best management practices, posters, and other information to engage the public.
For more information visit www.firewood.ca.gov
- Author: Deborah M Mathews
One of California's most adored flowering plants, impatiens, is being threatened by a serious pest. You may have noticed the common garden impatiens missing from nurseries, retail store shelves, and landscapes, parks, and gardens this year.
Impatiens are dying from a relatively new plant disease called impatiens downy mildew, caused by the fungus-like, oomycete pathogen Plasmopara obducens. The pathogen primarily affects varieties of Impatiens walleriana, or hybrids with an I. walleriana parent and wild impatiens (I. balsamina). Note that this pathogen does not affect New Guinea impatiens (Impatiens hawkeri) or other bedding plant genera. This disease develops rapidly, with a few leaves on apparently healthy impatiens beginning to show slight yellowing and stunting followed by development of white, powdery spores on the undersides of leaves, and later, by leaf and flower drop. Plants are likely to become completely defoliated within several weeks. The pathogen produces airborne spores, which can travel for many miles, as well as swimming zoospores and oospores, which can survive within soil and plant debris for long periods and infect healthy plants when replanted in the same area.
Early detection is especially critical for this disease since chemical control has been shown to be ineffective once sporulation begins. Scout routinely to identify and remove diseased plants before epidemics can result. Removing infected plants may limit spread to other areas of the landscape.
Consider growing alternative bedding plants that will grow well in shady areas of the landscape but that will not be affected by the disease. Some examples include Bergenia hybrids, Caladiums, Coral bells, Lobelia, New Guinea impatiens, Sweet alyssum, and wax begonias.
This article was originally published in the December 2013 issue of the UC IPM Green Bulletin./span>
- Editor: Pamela M. Geisel
- Author: Aubrey Bray
I love the taste of summer. For me the taste of summer is that first charcoal-grilled hot dog of the season, sun brewed iced tea, and the big bowl of slightly chilled cherries that is always present at summer BBQs. If you are about to start collecting your summer bounty of beautiful, red ripe cherries be aware that this year might not be the bumper crop you expected due to one pesky little problem.
Spotted wing drosophila (SWD), Drosophila suzukii, is a fruit fly that infests soft-fleshed fruit such as cherries, raspberries, blackberries, blueberries, and strawberries. A native of Japan, SWD found its way to California in 2008 and has been giving commercial and home gardening operations problems ever since. Unlike its relatives, SWD attacks fruit as it ripens as well as damaged or overripe fruit. This is due to the female’s serrated ovipositor that allows her to literally saw into healthy, intact fruit to lay eggs. Females oviposit or “sting” healthy ripening fruit and deposit 1-3 eggs per sting site, and can go on to sting many more times. Eggs hatch and grow into maggots that feed on the fruit, turning it brown and soft.
Bill Krueger, Farm Advisor and County Director for Glenn County Cooperative Extension, found SWD on his cherries this week. He identified the pest on an early-ripening variety, but hopes he’ll be able to protect his second variety that ripens a little later. He's lucky to have caught it, as most backyard gardeners won't see the microscopic punctures or other signs of SWD until it is too late.
Because SWD infest healthy fruit it is essential to identify early and take appropriate measures. Waiting until harvest to spray or take other measures will not be of any use because maggots are already in the fruit. Some management options highlighted in “Pest Notes” a publication of the UC Statewide Integrated Pest Management System Program, include: securing a fine mesh netting over whole plants pre-ripening to exclude adult females, early harvest to reduce exposure, and spraying organic insecticide spinosad (“Monterey Garden Insect Spray”) 2-3 weeks before harvest just as fruit turns from yellow to pink. Another application may be needed 7-10 days later.
For more information about SWD identification and management options see the UC IPM Pest Notes.