Lettuce Continued from Page 11
These nine lines are being studied for possible germplasm release to the seed companies. The Salinas researchers are also screening Romaine and crisp head let- tuce lines for their resistance to a combi- nation of pythium and wilt virus. Clark said the Leafy Greens Research Program and its handler members “in- vest research dollars in genetic research and pre-breeding efforts for resistance and other horticulturally important traits that are then available to seed companies developing commercially available leafy green varieties.” Additionally, the Lettuce Genome Sequencing Project at the University of California, Davis, is compiling genetic in- formation on cultivated lettuce to provide resources for other researchers seeking to address crop threats, including fusarium. “Lettuce now has a very high-quality reference genome,” Richard Michelmore, a UC Davis plant pathologist, said in July. Posing a question that inspires the effort, he asked, “Can we look at many of the genes available to breeders in this species rather than just one cultivar?” He added, “We’re getting there.” Michelmore’s report for the Leafy Greens research conference said 43 lettuce lines with fusarium resistance
Richard Michelmore, a plant pathologist at the University of California, Davis, is leading efforts to develop disease resistance in lettuce. Over the past year, researchers have released 43 lettuce lines with resistance to fusarium wilt.
were released over the past year, with re- searchers identifying 17 other lines that may have resistance. Fusarium wilt is a soil borne vascu- lar disease that kills infected seedlings and causes many plants that survive to become stunted and disfigured. The fungus, which is particularly trou- blesome in warmer lettuce regions of Fresno or southern Monterey counties, survives in the soil for many years.
USDA research plant pathologist Frank Martin reported that while only one race of lettuce fusarium has been found in California, three other races have been identified in Japan, Taiwan and the Netherlands. In other studies, researchers are preparing to release lettuce lines that show resistance to both races of verti- cillium wilt that have developed and spread in the Central Coast region in recent decades. Verticillium wilt first appeared in the region’s lettuce fields in 1995. The disease has since spread to more than 10,000 acres. The fungus also survives in the soil, and rotation is difficult because it can affect other common Central Coast crops, includ- ing strawberries, spinach and artichokes.
Work also continues in the never-end- ing struggle to keep up with lettuce downy mildew as the disease evolves to overcome variety resistance. For the last decade, Michelmore’s lab has tracked the rise and fall of five distinct races of downy mildew. Over the last five years, however, a ma- jor share of the lettuce downy mildew in the state has been of novel strains that cannot be identified as belonging to any of those races. Michelmore’s lab has evaluated 30 commonly grown lettuce varieties for their resistance or susceptibility to the disease. (Bob Johnson is a reporter in Monterey County. He may be contacted at bjohn11135@gmail.com.)
2023 Health & Safety on the Farm and Ranch
California Farm Bureau is pleased to offer this year-long program of training sessions presented by Nationwide. Select topics will be presented in both English and Spanish. Members, enjoy access to free classes! Register for the upcoming training webinars. Trainings will be presented via Zoom. The Hazardous Agricultural Materials (HAM) training must be attended in person at a participating County Farm Bureau office or at the California Farm Bureau office in Sacramento. For a list of class dates and to register, visit cfbf.com/FBE or call (800) 698-FARM for assistance. You will receive a Zoom link and details two days prior to your selected webinar date.
Carson Socal Honda Powersports 310-834-6632 www.socalhondapowersports.com
Fresno Clawson Motorsports 559-435-5020 www.clawsonmotorsports.com
Gridley Gridley Honda 530-846-5666 www.gridleyhonda.com
powersports.honda.com PIONEER 1000 IS ONLY FOR DRIVERS 16 YEARS AND OLDER. MULTI-PURPOSE UTILITY VEHICLES (SIDE-BY-SIDES) CAN BE HAZARDOUS TO OPERATE. FOR YOUR SAFETY, DRIVE RESPONSIBLY. ALWAYS WEAR A HELMET, EYE PROTECTION AND APPROPRIATE CLOTHING. ALWAYS WEAR YOUR SEAT BELT, AND KEEP THE SIDE NETS AND DOORS CLOSED. AVOID EXCESSIVE SPEEDS AND BE CAREFUL ON DIFFICULT TERRAIN. WE RECOMMEND THAT YOU COMPLETE THE RECREATIONAL OFFHIGHWAY VEHICLE (ROV) E-COURSE. THE FREE COURSE IS AVAILABLE AT WWW.ROHVA.ORG. READ THE OWNER’S MANUAL BEFORE OPERATING THE VEHICLE. NEVER DRIVE AFTER CONSUMING DRUGS OR ALCOHOL, OR ON PUBLIC ROADS. DRIVER AND PASSENGERS MUST BE TALL ENOUGH FOR SEAT BELT TO FIT PROPERLY AND TO BRACE THEMSELVES WITH BOTH FEET FIRMLY ON THE FLOOR. PASSENGER MUST BE ABLE TO GRASP THE HAND HOLD WITH THE SEAT BELT ON AND BOTH FEET ON THE FLOOR. RESPECT THE ENVIRONMENT WHEN DRIVING. Pioneer® is a registered trademark of Honda Motor Co., Ltd. ©2022 American Honda Motor Co., Inc. (08/22)
Modesto Honda Of Modesto 209-529-5424 www.hkmodesto.com
Yuba City Work & Play Powersports 530-673-5676 www.workplaypower.com
powersports.honda.com PIONEER 1000 IS ONLY FOR DRIVERS 16 YEARS AND OLDER. MULTI-PURPOSE UTILITY VEHICLES (SIDE-BY-SIDES) CAN BE HAZARDOUS TO OPERATE. FOR YOUR SAFETY, DRIVE RESPONSIBLY. ALWAYS WEAR A HELMET, EYE PROTECTION AND APPROPRIATE CLOTHING. ALWAYS WEAR YOUR SEAT BELT, AND KEEP THE SIDE NETS AND DOORS CLOSED. AVOID EXCESSIVE SPEEDS AND BE CAREFUL ON DIFFICULT TERRAIN. WE RECOMMEND THAT YOU COMPLETE THE RECREATIONAL OFFHIGHWAY VEHICLE (ROV) E-COURSE. THE FREE COURSE IS AVAILABLE AT WWW. ROHVA.ORG. READ THE OWNER’S MANUAL BEFORE OPERATING THE VEHICLE. NEVER DRIVE AFTER CONSUMING DRUGS OR ALCOHOL, OR ON PUBLIC ROADS. DRIVER AND PASSENGERS MUST BE TALL ENOUGH FOR SEAT BELT TO FIT PROPERLY AND TO BRACE THEMSELVES WITH BOTH FEET FIRMLY ON THE FLOOR. PASSENGER MUST BE ABLE TO GRASP THE HAND HOLD WITH THE SEAT BELT ON AND BOTH FEET ON THE FLOOR. RESPECT THE ENVIRONMENT WHEN DRIVING. Pioneer® is a registered trademark of Honda Motor Co., Ltd. ©2022 American Honda Motor Co., Inc. (08/22)
12 Ag Alert May 17, 2023
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