Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Kawasaki disease wikipedia , lookup
Transmission (medicine) wikipedia , lookup
Behçet's disease wikipedia , lookup
Sociality and disease transmission wikipedia , lookup
Onchocerciasis wikipedia , lookup
Chagas disease wikipedia , lookup
Hospital-acquired infection wikipedia , lookup
Infection control wikipedia , lookup
Schistosomiasis wikipedia , lookup
Germ theory of disease wikipedia , lookup
Globalization and disease wikipedia , lookup
Childhood immunizations in the United States wikipedia , lookup
Bacterial Ring Rot….a Wide Spread Problem….. What Does it Look Like & What to do When Found Philip B Hamm Plant Pathologist Oregon State University Hermiston Agricultural Research & Extension Center Why Have This “Conversation”? 1. Because we can not afford to concentrate on other issues and forget this very serious pathogen 2. Most have never seen this problem or it has been a long time since last seen 3. There was a number of farms that had this disease last year….at a large cost 4. The problem just doesn’t go away….it will likely be an issue in 2014 if proper practices are not followed Specific Areas to be Covered • Bacterial Ring Rot (BRR) – What is Bacterial Ring Rot and why it is important – Symptoms • Above ground • Below ground – Where does it come from…how does the disease happen – Management What is Bacterial Ring Rot? • A bacterial problem, seedborne, caused by Clavibacter michiganensis subsp. sepedonicus • Given the nature of bacteria, easily spread, particularly at seed cutting • Damage/loss is caused by the rot that occurs in the field, in storage, and issues during processing • This disease clearly is one, if not “THE” disease in potato not to have! EVER! What is Bacterial Ring Rot….continued • Infection – Wounds are necessary for ring rot bacteria to enter potatoes; readily transmitted during seed cutting – Handling (moving, shipping etc.) are all ways to wound tubers and provide a way for the bacteria to enter – Chewing insects, such as Colorado potato beetle and flea beetles have been reported to transmit the bacteria – BRR bacteria can survive in volunteer potato plants so contamination could occur when “volunteer” potatoes are mixed at harvest with the planted crop Why is this disease important? • Obvious…yield reduction (rot in the field and rot problems in storage) • Processor contracts have little or zero tolerance for this disease….fields were rejected this past year due to this disease – Lightly symptomatic or non symptomatic but infected tubers result in discolored fries or chips Symptoms Foliar Symptoms of BRR External Tuber Symptoms of BRR Internal Tuber Symptoms of BRR Name comes from This symptom Where does it come from…how does the disease happen? Where does it come from…how does that happen? • Essentially poor sanitation – This is the reason why recommendations were originally made about cleaning and disinfecting equipment and facilities between lots and between years – Generally potatoes are resilient…In other words they overcome many negative things we do to them….but BRR is an exception…this one will get the grower!!! Where does it come from…how does that happen • Seldom seen by most potato growers in their career…so the problem is not recognized • Progressive – Seed lot gets contaminated in one of the years of seed lot expansion due to poor sanitation practices • Infection starts out at very low incidence • Next generation or even two may have little or no symptomatic plants • When the Gen 3 seed is cut by the commercial grower the level of infection could easily become 1-5% • Therefore the older the generation (3, 4, 5) the greater the chance of BRR at significant levels • The earlier the generation the seed lot is infected the higher the potential incidence of infection Management…. whether seed grower or commercial grower Management • The use of certified disease free seed – Adequately tested/observed and confirmed “Zero” for this specific disease • 4400 tubers from each “average” size seed lot, twice that many if a large seed lot. 1100 tubers minimum for small lots. • Tested with PCR using proscribed methods • Winter grow out field readings also helpful but do not take the place of laboratory testing Management ..Continued • The maintenance of a very strict and comprehensive sanitation program…why? – The bacteria are capable of surviving 2-5 yrs. in dried slime on the surfaces of crates, bins, burlap sacks, truck beds, harvesting and grading equipment. • Clean equipment between seed lots and between years. – Temperatures below freezing does not eliminate the bacteria – Bacteria do not survive in soil but can survive in volunteer potatoes…control volunteers! Management Continued…. Sanitation of Facilities • Remove all trash (tubers, vines, soil, broken boxes and old bags, etc.) from the storage, and properly discard or burn • Once cleaned, storage bins and walls and floors should be thoroughly washed with a highpressure washer using hot soapy water, and then rinsed well • After washing and rinsing, a disinfectant must be applied according to label directions Management Continued…. Sanitation during seed cutting • The bacteria can be spread by knives during seed cutting (one infected tuber can spread the bacteria to the next 20-100 seed pieces • All containers, tools, and implements (including knives, cutters, belts, graders, truck beds, planters, etc.) should be cleaned, and then sanitized • Clean and disinfect cutting equipment, preferably 3x per day, and always between lots • Open-cell sponge rollers that absorb water (and bacteria) are best avoided--use water impermeable (closed-cell) rollers instead Management Continued… Sanitation During Planting • Disinfect trucks and planter(s) between each seed lot • Don’t use a pick planter • Do not plant in a field with BRR last year • Do not plant in a field with volunteers with a history of this disease What to do or not do if found in the field • Be watchful…again confirm by lab testing • Not all tubers are infected and/or will exhibit symptoms if a hill is dug • No pesticide can be applied that will reduce infection • Letting infected tubers rot before harvest may limit the number of tubers at harvest that are infected • Placing tubers in storage with BRR is a potential time bomb given the chance of hot spots in the pile developing from infected potatoes Summary • BRR is a very significant potato disease problem • The presence of this pathogen in potato production is cyclic – 10-12 yr cycle; 4-5 yr impact per cycle – Likely due to the failure to maintain good sanitation practices – Also likely due to inadequate testing methods to confirm BRR • For management….Maintain/Increase sanitation efforts • For management…New testing technology and increased sample size could have a significant impact on confirming this disease in a seed lot • Don’t plant seed unless it has been correctly tested for BRR Questions?? • Special thanks to Brenda Schroeder and Debra Inglis for supplying some of the slides used today.