Researchers target threat from ancient rice disease By Bob Johnson
Now researchers are focusing on an fungal disease turning up in California rice growing regions in recent years as burning has decreased. Bakanae is an ancient disease in Asian rice production systems. But it did not appear in California until the start of this century. It has since spread to all the growing regions in the state. “I seemed to find more bakanae the last three years,” Luis Espino, University
of California Cooperative Extension rice farm advisor, said. “It is seed borne and causes blank panicles.” A month after planting, seedlings in- fected with bakanae look slender, elon- gated and slightly chlorotic. By then it is too late to manage the dis- ease, however, because if these slender stems survive, they will produce blank panicles and leave fungal pathogens in the soil.
Researchers studying the disease shared insights in an online session for California rice growers earlier this year. They said one step to control bakanae is to plant seed that is not infested—be- cause even the heat inside a truck can be enough to germinate the spores of infested seeds. Although soaking seeds in a mild Clorox treatment shortly before planting can be effective, seed companies and researchers are working on seed treatments that are economical, practical and effective. Stem rot disease first appears as black lesions at the water line, caused when flooding brings pathogens that survived in the soil up to the water line. Stems infected with this disease can die off without producing rice and can also make the crop more susceptible to lodging. Farm advisors say it is important to avoid using excess nitrogen, which makes stem rot worse and to minimize the amount of infected crop residue left in the field after harvest. The fungicide Quadris can be effective against stem rot and variety choice can also significantly reduce the impact of the disease, researchers say. Variety choice makes less of a dif- ference in managing aggregate sheath spot, a crop disease that first appears as circular spots at the water line at the tillering stage. Quadris can also be effective as a pre- ventive material for aggregate sheath spot. Minimizing the pathogen load on crop residue is also important in managing this disease and, if burning is not possi- ble removing residue from the field may be advisable, Espino said. (Bob Johnson is a reporter in Monterey County. He may be contacted at bjohn11135@gmail.com.) The California Department of Food and Agriculture is seeking to fill two va- cancies on its Feed Inspection Advisory Board Technical Advisory Subcommittee. Applicants must have general knowl- edge about the California feed industry as well as technical, applied and scientific expertise in fields of toxicology, pathol- ogy and ruminant and non-ruminant nutrition. The term of office for subcom- mittee members is three years. Applicants should send a résumé and a Feed TASC Prospective Member Appointment Questionnaire, found at www.cdfa.ca.gov/is/ffldrs/pdfs/FIAB- TASC_PMAQ.pdf, to SAFE@cdfa.ca.gov. The application deadline is Sept. 30. For further information, call 916-900-5022 or visit www.cdfa.ca.gov/ is/ffldrs/Feed_FIAB.html. Feed inspection panel has two vacancies to fill
Rice growers are still piecing together management strategies for diseases that have become more problematic in the decades since burning crop residue after harvest stopped being a standard practice. Burning led to smoke over the Sacramento Valley, but it had the ben- efit of killing pathogens on residue that could otherwise live in the soil and infest future crops.
yf&r farmpac Clay shoot Fundraiser
Benefiting the Fund to Protect the Family Farm ( FarmPAC ® )
Saturday October 22 2022 Yolo Sportsmen's Association 24189 Aviation Avenue Davis, California 95616
Registration Open $100 per person $400 for a team of 4 includes clays and lunch
Limited to 100 shooters $35 lunch only
sponsorship opportunities available
For more information and to register, visit www.cfbf.com/farmpac. Contributions or gifts to FarmPAC are not tax-deductible. Paid for by California Farm Bureau Federation Fund to Protect the Family Farm (FarmPAC ® ).
12 Ag Alert September 14, 2022
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