Information Requests Monitoring System

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Request ID: 127
Request From: Steve Toth
Date Requested: Jun 03, 2005
Request: Thank you for your recent replies to questions on oxytetracycline and streptomycin. USDA's Office of Pest Management Policy has a conference call with the EPA regarding oxytetracycline and streptomycin on June 21 and has received additional questions. We have expressed to USDA OPMP our displeasure over receiving additional questions about the same chemicals, but it is really out of the control of OPMP. Please pass along these questions to the experts in your respective states/territories and submit their responses to the Southern Region IPM Center Information Request Monitoring System. Please submit the responses by Friday, June 17, 2005. Thanks. Steve Toth ------------------------------------------ Where possible, please provide information for both oxytetracycline and streptomycin. Use: 1. Approximately how many times per year is this pesticide typically applied? 2. What are the typical application rates (as opposed to maximum label rates)? 3. What are typical reapplication intervals (in days)? 4. What factors influence the number of times per year this pesticide is applied (i.e., how do growers determine whether or not to apply/reapply)? 5. In the last ~15 years, what is the maximum number of times per year this pesticide has been applied? 6. What is the most common application method for this pesticide (e.g., ground spray)? 7. If applicable, what precautions are taken to prevent spray drift or off-site pesticide migration? 8. Over the years, has the typical number of applications increased, decreased, or stayed the same? 9. Over the years, have application rates (i.e., number of pounds of active ingredient applied per acre) increased, decreased, or stayed the same? Target pests: 10. Is this pesticide the only (or one of very few) tools for combating any pests? If so, please list the pests and why alternatives are ineffective. 11. To what extent do growers rely on this pesticide to combat fire blight and bacterial spot? 12. What are the alternatives for this pesticide (in particular for fire blight, bacterial spot, and any pests identified in question 10)? 13. Are the alternative products comparable in efficacy and price to this pesticide? Antibiotic resistance: 14. How do growers react to pests that show resistance to this pesticide? Do they use an alternative product, apply more of this pesticide, or use other methods to manage pests? 15. What strategies, if any, are currently in place or being developed to monitor and/or reduce the likelihood of contributing to antibiotic resistance both in target and non-target organisms? 16. What amount of public concern has been encountered with the use of antibiotics as pesticides? If applicable, please provide examples. 17. To what degree are you concerned that the use of this pesticide may result in increased resistance to antibiotics used to treat human diseases (pathogens) or that the use of these chemicals may increase the number of human pathogens that are resistant to antibiotics? 18. How fast is resistance developing to this pesticide? 19. If pests become resistant to this pesticide, what is the proposed path forward?

Responses
Responder: Allen Straw
State: TN
Date Requested: Jun 06, 2005
Response: RE: Streptomycin and Oxytetracycline, Response needed by June 17th........ >===== Original Message From Steve_Toth@ncsu.edu ===== MESSAGE FROM: Steve_Toth@ncsu.edu DATE: 03/06/2005 MESSAGE TO: Darrell Hensley This is a request for information from Steve Toth Thank you for your recent replies to questions on oxytetracycline and streptomycin. USDA's Office of Pest Management Policy has a conference call with the EPA regarding oxytetracycline and streptomycin on June 21 and has received additional questions. We have expressed to USDA OPMP our displeasure over receiving additional questions about the same chemicals, but it is really out of the control of OPMP. Please pass along these questions to the experts in your respective states/territories and submit their responses to the Southern Region IPM Center Information Request Monitoring System. Please submit the responses by Friday, June 17, 2005. Thanks. Steve Toth ------------------------------------------ Where possible, please provide information for both oxytetracycline and streptomycin. Use: 1. Approximately how many times per year is this pesticide typically applied? 1 to 2 2. What are the typical application rates (as opposed to maximum label rates)? Most growers apply at the maximum labeled rate. 3. What are typical reapplication intervals (in days)? Reapplication intervals probably range from 7 to 14 days, averaging about 10 days. 4. What factors influence the number of times per year this pesticide is applied (i.e., how do growers determine whether or not to apply/reapply)? The primary factor is habit, but weather is an important factor along with disease pressure the season prior. 5. In the last ~15 years, what is the maximum number of times per year this pesticide has been applied? Possibly 4 times. 6. What is the most common application method for this pesticide (e.g., ground spray)? In fruit, ground application with an air blast sprayer. In transplant production, ground application with a backpack or pump up sprayer. 7. If applicable, what precautions are taken to prevent spray drift or off-site pesticide migration? Applying when the wind is minimal. 8. Over the years, has the typical number of applications increased, decreased, or stayed the same? Stayed the same to slightly decreased. 9. Over the years, have application rates (i.e., number of pounds of active ingredient applied per acre) increased, decreased, or stayed the same? Stayed the same. Target pests: 10. Is this pesticide the only (or one of very few) tools for combating any pests? If so, please list the pests and why alternatives are ineffective. Yes; these products are the only products we have for bacterial disease control in stone and pome fruits. Streptomycin is also an integral step in the control of bacterial diseases in transplant production of fruiting vegetables (tomatoes and peppers). 11. To what extent do growers rely on this pesticide to combat fire blight and bacterial spot? 100% 12. What are the alternatives for this pesticide (in particular for fire blight, bacterial spot, and any pests identified in question 10)? In pome and stone fruit, there are no alternatives. In transplant production, Actigard and coppers are labeled for field use, but Streptomycin and copper are the only products that can be used in greenhouse. Again, all of these are tools in bacterial disease control. Using all of them, we can still have serious bacterial disease problems in tomatoes. 13. Are the alternative products comparable in efficacy and price to this pesticide? There are no alternatives for tree fruit or transplant production. Antibiotic resistance: 14. How do growers react to pests that show resistance to this pesticide? Do they use an alternative product, apply more of this pesticide, or use other methods to manage pests? I have seen little evidence of resistance to these products. However; since there are no alternatives, they would generally apply higher rates, look for other cultural controls, and start looking for alternative chemical controls. 15. What strategies, if any, are currently in place or being developed to monitor and/or reduce the likelihood of contributing to antibiotic resistance both in target and non-target organisms? Following label instructions for resistance management. 16. What amount of public concern has been encountered with the use of antibiotics as pesticides? If applicable, please provide examples. I have witnessed very little concern. I do not believe that the general public even know that some antibiotic's are being used as pesticides. 17. To what degree are you concerned that the use of this pesticide may result in increased resistance to antibiotics used to treat human diseases (pathogens) or that the use of these chemicals may increase the number of human pathogens that are resistant to antibiotics? I am not very concerned about this issue. 18. How fast is resistance developing to this pesticide? Personally, I have seen little resistance developing. 19. If pests become resistant to this pesticide, what is the proposed path forward? Find something new. Because there is nothing else at this time. Please respond online using the following URL http://www.sripmc.org/requests/answer.cfm?RID=127 Please respond even if the requested action does not impact your state(s). -------------------------- Darrell Hensley University of Tennessee 2431 Joe Johnson Drive, 205 PSB Knoxville, TN 37996-4560 Phone (865) 974-7958 Fax (865) 974-8868 email = dhensley@utk.edu

Responder: David Lockwood
State: TN
Date Requested: Jun 06, 2005
Response: 1. Streptomycin for fireblight control is applied about 3 times per year, depending on weather conditions during the bloom period for apples. With the variety Mutsu (Crispin), 2 addtional applications may be used for blister spot control. Oxytetracycline is being used for bacterial spot control in peach. It is being applied 4 to 5 times during the growing season. 2. The typical application rate for streptomycin is 4.8 to 8 ounces per 100 gallons or 1 1/2 to 2 1/2 pounds per acre. The higher rate is suggested for orchards having a history of fireblight infections and where environmental conditions favor infections. Oxytetracycline (Mycoshield 17W)is used at the rate of 0.75 to 1.0 lbs. per acre 3. When weather conditions favor infection, streptomycin is applied every 3 to 4 days beginning at first bloom and going until petal fall. Oxytetracycline used for bacterial spot control should be applied on a 5 to 7 day schedule depending on weather conditions. 4. As stated in question #3, weather conditions during bloom will affect the number of streptomycin applications made for control of fireblight. Temperature and relative humidity affect the infection potential as can rainfall. The duration of bloom will also impact the number of applications made. This period will vary somewhat from year to year depending on weather conditions. Moisture is very conducive to bacterial spot infection. 5. Over the last 15 years, the maximum number of streptomycin applications a grower might have used will be about 45 to 50. Over the last 15 years, the maximum number of oxytetracycline applications a grower might have used is about 35 to 40. 6. All applications of streptomycin and oxytetracycline in Tennessee are made by ground equipment, primarily air blast sprayers. 7. Protections against spray drift and off-target migration include spraying only when conditions are relatively calm and adjusting the sprayer for the size trees to be sprayed. 8. The number of applications made each year have remained about the same over the years. 9. Application rates have remained the same for the last several years. 10. Streptomycin is one of very few materials showing benefits for the control of fireblight. Since streptomycin resistance has not been found in Tennessee, oxytetracycline has not been used. Therefore, streptomycin is the only material for use during the critical bloom period. Resistant vatieties are employed wherever possible to diminish dependence on pesticides for bacterial spot control. Copper fungicides are also used for control of bacterial leaf spot. It is used in the Pink stage and can be used in place of or in rotation with oxytetracycline. leaf burn may be associated with the use of copper during the growing season. 11. Streptomycin is part of a comprehensive management program aimed at fireblight. It is the only material used during bloom for control and has shown to reduce the severity of infections when used in a timely manner. Therefore, growers rely on the use of streptomycin very heavily. Growers rely on the use of oxytetracycline for control of bacterial spot moreso than coppers during the growing season. 12. Oxytetracycline is the only alternative to streptomycin for control of firebblight during bloom. Since resistance to streptomycin has not been reported in Tennessee, all growers still rely on streptomycin. Despite label clains, Alitte has not shown any beneficial results for reducing fireblight problems, therefore it is not used. Apogee is being used by a few growers to lessen the period of shoot elongation, thus lessening the potential time period for shoot blight infection. A copper spray prior to bloom is being used by most growers. Cultural practices being utilized to lessen fireblight problems include dormant pruning and modest nitrogen fertilization. Alternatives to the use of oxytetracycline include the use of resistant varieties where possible and the use of copper sprays in place of, or in rotation with, oxytetracycline. 13. Since no resistance to streptomycin has been reported in Tennessee and since streptomycin continues to be available, growers have not tried to secure alternative products. Work with the use of copper sprays for control of bacterial spot has shown control about like that which has been received through the use of oxytetracycline. However, in Tennessee, testing has not been sufficient to warrant replacing oxytetracycline in recommendations. 14. To lessen the potential for resistance, growers are using streptomycin only at the recommended rates and times. They have focused more on sprays and practices that would be of value in lessening fireblight potential. For bacterial spot control, growers may elect to try copper sprays instead of oxytetracycline when the latter does not appear to be giving control. Hwever, resistance has not been identified in Tennessee. 15. The answer is the same as for question #14. 16. We have not experienced much public concern over the use of antibiotics as pesticides. 17. I am not concerned regarding the use of streptomycin and oxytetracycline for plant disease control as it might impact the resistance to them for human diseases. Judicious use of the materials should lessen the potential for this. 18. I do not know how fast resistance to these pesticides is developing. It is difficult to gauge under field conditions since the pesticides do not provide total control and so many factors can affect the severity of the diseases they are supposed to control. 19. If resistance does show up, alternate materials will be investigated. Cultural programs that lessen disease potential will be stressed more (although growers are currently doing a good job in this area). Cultivar selection for future plantings will have to be emphasized and selection of those showing lower levels of susceptibility will need to be selected. In some cases, however, suitable options do not exist. Breeding programs will nave to focus on disease resistance.

Responder: Phillip Brannen
State: GA
Date Requested: Jun 06, 2005
Response: 1. Approximately how many times per year is this pesticide typically applied? OXYTETRACYCLINE IS APPLIED AS MANY AS SIX OR MORE APPLICAIONS. STREPTOMYCIN IS GENERALLY APPLIED BETWEEN 3-6 TIMES IN GA 2. What are the typical application rates (as opposed to maximum label rates)? TYPICAL RATES ARE THE FULL LABEL RATES FOR STREPTPYCIN. OXYTETRACYCLINE RATES ARE GENERALLY AROUND 12 OZ COMMERICIAL PRODUCT PER ACRE 3. What are typical reapplication intervals (in days)? ONE WEEK FOR OXYTETRACYCLINE AND 3-4 DAYS FOR STREP 4. What factors influence the number of times per year this pesticide is applied (i.e., how do growers determine whether or not to apply/reapply)? FOR BOTH ANTIBIOTICS, THERE ARE PROGRAMS AVAILABLE WHICH HELP TO DETERMINE THE APLLICATION TIMING. SOME PRODUCERS USE THESE, BUT OTHERS DETERMINE BASED ON A A GENERAL ASSESSMENT OF THE WEAHTER. 5. In the last ~15 years, what is the maximum number of times per year this pesticide has been applied? PROBABLY SIX FOR STREPTOMYCIN AND NINE FOR OXYTETRACYCLINE 6. What is the most common application method for this pesticide (e.g., ground spray)? AIRBLAST GROUND SPRAY IN BOTH CASES 7. If applicable, what precautions are taken to prevent spray drift or off-site pesticide migration? PRODUCERS GENERALLY AVOID SPRAYING DURING WINDY CONDITIONS. 8. Over the years, has the typical number of applications increased, decreased, or stayed the same? APPLICATIONS ARE ROUGHLY THE SAME, THOUGH SOME PEACH PRODUCERS ARE USING LOW RATES OF COPPER MATERIALS INSTEAD OF OXYTETRACYCLINE, LARGELY DUE TO COST SAVINGS 9. Over the years, have application rates (i.e., number of pounds of active ingredient applied per acre) increased, decreased, or stayed the same? ROUGHLY THE SAME. Target pests: 10. Is this pesticide the only (or one of very few) tools for combating any pests? If so, please list the pests and why alternatives are ineffective. OXYTETRACYCLINE IS THE ONLY REGISTERED MATERIAL FOR USE IN THE COVERS SPRAYS FOR CONTROL OF BACTERIALS SPOT ON PEACH. COPPER CAN CAUSE DAMAGE DURING THIS TIME FRAME, SO IT IS NOT IDEAL. STREPTOMYCIN IS STILL THE MOST EFFECTIVE MATERIAL FOR CONTROL OF FIRE BLIGHT. 11. To what extent do growers rely on this pesticide to combat fire blight and bacterial spot? HEAVILY ON BOTH COUNTS 12. What are the alternatives for this pesticide (in particular for fire blight, bacterial spot, and any pests identified in question 10)? FOR STREPTOMYCIN, THERE IS NO EFFECTIVE ALTERNATIVE IN GEORGIA. OTHER REGISTERED PRODUCTS ARE NOT EFFECTIVE UNDER OUR CONDITIONS. FOR OXYTETRACYCLIN, COPPER CAN BE USED IN 2-3 EARLY COVER SPRAYS, BUT NO PRODUCTS ARE AVAILABLE FOR LATER COVER SPRAYS 13. Are the alternative products comparable in efficacy and price to this pesticide? NA. Antibiotic resistance: 14. How do growers react to pests that show resistance to this pesticide? Do they use an alternative product, apply more of this pesticide, or use other methods to manage pests? WE HAVE NOT OBSERVED RESISTANCE TO EITHER ANTIBIOTIC TO DATE. GROWERS WILL NOT LIKELY APPLY MORE, SINCE THIS WOULD BE ILLEGAL. WE WOULD HAVE TO FIND ALTERNATIVES, OF WHICH THERE ARE NO GOOD ONES AT THIS TIME. 15. What strategies, if any, are currently in place or being developed to monitor and/or reduce the likelihood of contributing to antibiotic resistance both in target and non-target organisms? WE ARE EXPLORING THE ALTERNTION OF LOW RATES OF COPPER FOR ALTERNATION WITH OXYTETRACYCLINE IN PEACH. IF THIS WORKS, IT MAY HELP. IN THE CASE OF STREPTOMYCIN, WE DO NOT HAVE GOOD RESISTANCE MANAGEMENT OPTIONS. 16. What amount of public concern has been encountered with the use of antibiotics as pesticides? If applicable, please provide examples. NO PUBLIC CONCERNS HAVE BEEN BROUGHT FORWARD IN GEORGIA. 17. To what degree are you concerned that the use of this pesticide may result in increased resistance to antibiotics used to treat human diseases (pathogens) or that the use of these chemicals may increase the number of human pathogens that are resistant to antibiotics? I AM NOT OVERLY CONCERNED ABOUT THIS. I THINK IT IS ACADEMICALLY POSSIBLE, BUT HOSPITAL USE IS LIKELY TO RESULT IN MORE SIGNIFICANT RISKS IN MY OPINION. 18. How fast is resistance developing to this pesticide? TO DATE, NONE HAS BEEN OBSERVED IN GEORGIA. IN THE CASE OF STREPTOMYCIN, I AM SURPRISED AT THIS. THE BACTERIAL SPOT PATHOGEN IN PEACH EVIDENTLY DOES NOT READILY DEVELOP RESISTANCE TO OXYTETRACYCLINE, BUT IT IS STILL A REAL CONCERN TO ME. 19. If pests become resistant to this pesticide, what is the proposed path forward? FOR FIRE BLIGHT, WE WOULD APPLY FOR A SECTION 18 FOR OXYTETRACYCLINE. FOR OXYTETRACYCLINE, WE WOULD HAVE TO REGISTER LOW RATES OF COPPER FOR THE ENTIRE COVER SPRAY PERIOD, BUT THIS WOULD BE AN UPHILL BATTLE, SINCE COMPANIES ARE RISK-AVERSE RELATIVE TO THE POSSIBILITY OF LAW SUITS FROM DAMAGED TREES.

Responder: John Hartman
State: KY
Date Requested: Jun 06, 2005
Response: Response: 1. Approximately how many times per year is this pesticide typically applied? STREPTOMYCIN IS TYPICALLY APPLIED 2-4 TIMES PER SEASON. OXYTETRACYCLINE IS NOT USED MUCH IN KENTUCKY. 2. What are the typical application rates (as opposed to maximum label rates)? STREPTPYCIN IS APPLIED GENERALLY AT THE 2 LB/A RATE. OXYTETRACYCLINE WOULD BE USED AT THE LABELED RATE. 3. What are typical reapplication intervals (in days)? STREPTOMYCIN IS REAPPLIED TO APPLES EVERY 4 DAYS DURING BLOOM. 4. What factors influence the number of times per year this pesticide is applied (i.e., how do growers determine whether or not to apply/reapply)? MANY GROWERS USE THE MARYBLYT COMPUTER PROGRAM OR THE EQUVALENT EXPERIENCE-BASED PROGRAM; SOME USE MARYBLYT-BASED WARNINGS ISSUED BY UNIVERSITY SPECIALISTS. APPLE GROWERS WHO ACTIVELY PARTICIPATE IN OUR APPLE IPM PROGRAMS AVERAGE 1.5 - 2 STREPTOMYCIN SPRAYS PER SEASON WHILE OTHER GROWERS APPLY 3.5 SPRAYS. STREPTOMYCIN IS ONLY USED DURING BLOOM - USE AT OTHER TIMES IS STRONGLY DISCOURAGED. 5. In the last ~15 years, what is the maximum number of times per year this pesticide has been applied? WE HOPE, ONLY 4 TIMES. GROWERS ARE TOLD NOT TO EXCEED 4 APPLICATIONS PER SEASON IN ORDER TO AVOID RESISTANCE TO STREPTOMYCIN. 6. What is the most common application method for this pesticide (e.g., ground spray)? GROWERS USE AN AIRBLAST GROUND SPRAYER. 7. If applicable, what precautions are taken to prevent spray drift or off-site pesticide migration? APPLE GROWERS TRY TO SPRAY STREPTOMYCIN LATE IN THE DAY WHEN THE AIR IS STILL. 8. Over the years, has the typical number of applications increased, decreased, or stayed the same? NUMBERS OF STREPTOMYCIN APPLICATIONS HAVE DECREASED, ESPECIALLY FOR APPLE IPM PARTICIPATING GROWERS. 9. Over the years, have application rates (i.e., number of pounds of active ingredient applied per acre) increased, decreased, or stayed the same? RATES ARE THE SAME. Target pests: 10. Is this pesticide the only (or one of very few) tools for combating any pests? If so, please list the pests and why alternatives are ineffective. STREPTOMYCIN IS THE ONLY EFFECTIVE LABELED MATERIAL FOR CONTROL OF FIRE BLIGHT PRIMARY INFECTIONS (DURING BLOOM). 11. To what extent do growers rely on this pesticide to combat fire blight and bacterial spot? APPLE GROWERS RELY VERY HEAVILY ON STREPTOMYCIN. 12. What are the alternatives for this pesticide (in particular for fire blight, bacterial spot, and any pests identified in question 10)? THERE IS NO EFFECTIVE ALTERNATIVE FOR STREPTOMYCIN UNDER KENTUCKY CONDITIONS. 13. Are the alternative products comparable in efficacy and price to this pesticide? THERE ARE NONE AVAILABLE. Antibiotic resistance: 14. How do growers react to pests that show resistance to this pesticide? Do they use an alternative product, apply more of this pesticide, or use other methods to manage pests? STREPTOMYCIN RESISTANCE HAS NOT BEEN DOCUMENTED IN KENTUCKY. 15. What strategies, if any, are currently in place or being developed to monitor and/or reduce the likelihood of contributing to antibiotic resistance both in target and non-target organisms? GROWERS MANAGE STREPTOMYCIN RESISTANCE BY LIMITING THE NUMBER OF SEASONAL APPLICATIONS TO 4 PER YEAR. 16. What amount of public concern has been encountered with the use of antibiotics as pesticides? If applicable, please provide examples. OUR EDUCATIONAL PROGRAMS ADVISE AGAINST USE OF STREPTOMYCIN ON HOME FRUIT ORCHARDS AND FLOWERING FRUIT TREES IN THE LANDSCAPE TO MINIMIZE HUMAN MICROBE EXPOSURE TO ANTIBIOTIC RESISTANT ERWINIA AMYLOVORA. COMMERCIAL GROWERS ONLY APPLY DURING THE RELATIVELY SHORT BLOOM TIME IN EARLY SPRING WHEN THERE IS LITTLE EXPOSURE TO HUMANS IN THE ORCHARD. 17. To what degree are you concerned that the use of this pesticide may result in increased resistance to antibiotics used to treat human diseases (pathogens) or that the use of these chemicals may increase the number of human pathogens that are resistant to antibiotics? THIS SHOULD BE AN IMPORTANT CONCERN FOR ALL OF US WHICH IS WHY STREPTOMYCIN IS SUGGESTED FOR USE ONLY IN CIRCUMSTANCES WHERE HUMAN EXPOSURE TO FIRE BLIGHT RESISTANT BACTERIA IS MINIMIZED. WE NEED NEW PLANT AGRICULTURAL ANTIBIOTICS THAT ARE NOT USED IN ANIMAL AND HUMAN MEDICINE. 18. How fast is resistance developing to this pesticide? STREPTOMYCIN RISISTANCE IS NOT BEING OBSERVED, BUT IS AN IMPORTANT CONCERN. 19. If pests become resistant to this pesticide, what is the proposed path forward? GROW MORE FIRE BLIGHT-RESISTANT TREES. PAY MORE ATTENTION TO CULTURAL PRACTICES SUCH AS APPLICATION OF APOGEE, A GROWTH REGULATOR, PROPER FERTILIZATION AND PRUNING.

Responder: Charles Luper
State: OK
Date Requested: Jun 16, 2005
Response: Please see responses from Dr. Sharon Von Broembsen in the attached file.
Attachment included in response [Download]

Responder: Mark Mossler
State: FL
Date Requested: Jun 16, 2005
Response: Oxytetracycline (OTC) use in Florida - This antibiotic is used for lethal yellows disease of palm. OTC is injected into coconut palms at a rate of 1-3 g ai per palm once every 4 months. The overall use of this product in the landscape is probably similar to what it was 10 years ago and that probably won't change much. We know of no evidence of resistance of phtyoplasmas such as the one causing LY to OTC anywhere in the world and recommended application rates and frequencies have not changed in over 30 years. This product is injected into palm trunks, so there is no impact on non-target plants. Keeping this in mind, the questions are answered thusly: >1. Approximately how many times per year is this pesticide typically >applied? Can be continuous > >2. What are the typical application rates (as opposed to maximum label >rates)? 1-3 g ai/tree > >3. What are typical reapplication intervals (in days)? If the disease is not controlled the first time, it will be dead - so there is no retreatment generally > >4. What factors influence the number of times per year this pesticide is >applied (i.e., how do growers determine whether or not to >apply/reapply)? Growers treat based on presence of vector (insect) in area and sometimes beginning of signs > >5. In the last ~15 years, what is the maximum number of times per year >this pesticide has been applied? NA > >6. What is the most common application method for this pesticide (e.g., >ground spray)? Injected into trunk > >7. If applicable, what precautions are taken to prevent spray drift or >off-site pesticide migration? Injected into trunk > >8. Over the years, has the typical number of applications increased, >decreased, or stayed the same? Stayed the same - one > >9. Over the years, have application rates (i.e., number of pounds of >active ingredient applied per acre) increased, decreased, or stayed the >same? Stayed the same > >Target pests: > >10. Is this pesticide the only (or one of very few) tools for combating >any pests? If so, please list the pests and why alternatives are >ineffective. This is the only treatment for palm lethal yellows disease > >11. To what extent do growers rely on this pesticide to combat fire >blight and bacterial spot? Not at all in FL. > >12. What are the alternatives for this pesticide (in particular for fire >blight, bacterial spot, and any pests identified in question 10)? No alternatives have been identified for lethal yellows control > >13. Are the alternative products comparable in efficacy and price to >this pesticide? NA > >Antibiotic resistance: > >14. How do growers react to pests that show resistance to this >pesticide? Do they use an alternative product, apply more of this >pesticide, or use other methods to manage pests? No resistance seen in 30 years > >15. What strategies, if any, are currently in place or being developed >to monitor and/or reduce the likelihood of contributing to antibiotic >resistance both in target and non-target organisms? No programs currently in place > >16. What amount of public concern has been encountered with the use of >antibiotics as pesticides? If applicable, please provide examples. None > >17. To what degree are you concerned that the use of this pesticide may >result in increased resistance to antibiotics used to treat human >diseases (pathogens) or that the use of these chemicals may increase the >number of human pathogens that are resistant to antibiotics? Coconuts from treated trees not to be eaten (by label), incidental ingestion may provide minor transient dose with insignificant effect > >18. How fast is resistance developing to this pesticide? Not developing because many cases not treated - only the most precious/desired palms are treated > >19. If pests become resistant to this pesticide, what is the proposed >path forward? None currently identified

Responder: Mark Mossler
State: FL
Date Requested: Jun 16, 2005
Response: Streptomycin use in Florida - This antibiotic is used for controlling pectolytic bacteria that affect vegetative tropical ornamental plant propagation. Diffenbachia and chrysanthemums (mums) cuttings are soaked in streptomycin solution prior to planting. For mums, that solution is 50 PPM. For diffenbachia, a 200 PPM treatment solution is used initially at planting, and then a 100 PPM solution may be applied weekly thereafter during establishment and early growth. Extension professionals feel that streptomycin resistance is in the general population in FL, but others have success when using it (they may not have the problem but use it anyway). Keeping this in mind, the questions are answered thusly: >1. Approximately how many times per year is this pesticide typically >applied? Can be weekly during early establishment > >2. What are the typical application rates (as opposed to maximum label >rates)? 50 for 4 hours (mums)or 200 PPM for 20 minutes (diffenbachia) > >3. What are typical reapplication intervals (in days)? Can be weekly > >4. What factors influence the number of times per year this pesticide is >applied (i.e., how do growers determine whether or not to >apply/reapply)? Treatment based on prophylacsis > >5. In the last ~15 years, what is the maximum number of times per year >this pesticide has been applied? Can be weekly > >6. What is the most common application method for this pesticide (e.g., >ground spray)? Cuttings by immersion of plant section or stem, spray with 100 PPM solution > >7. If applicable, what precautions are taken to prevent spray drift or >off-site pesticide migration? Typically used in greenhouse > >8. Over the years, has the typical number of applications increased, >decreased, or stayed the same? Stayed the same > >9. Over the years, have application rates (i.e., number of pounds of >active ingredient applied per acre) increased, decreased, or stayed the >same? Stayed the same > >Target pests: > >10. Is this pesticide the only (or one of very few) tools for combating >any pests? If so, please list the pests and why alternatives are >ineffective. This is a questionable treatment tool > >11. To what extent do growers rely on this pesticide to combat fire >blight and bacterial spot? Not at all in FL. > >12. What are the alternatives for this pesticide (in particular for fire >blight, bacterial spot, and any pests identified in question 10)? Most soft-rotting bacteria can be/are controlled culturally. Soft rot indicative of to much unutilized (freestanding) water > >13. Are the alternative products comparable in efficacy and price to >this pesticide? NA > >Antibiotic resistance: > >14. How do growers react to pests that show resistance to this >pesticide? Do they use an alternative product, apply more of this >pesticide, or use other methods to manage pests? Some keep using it even with suspected resistance, but most successful growers bacterial rot culturally > >15. What strategies, if any, are currently in place or being developed >to monitor and/or reduce the likelihood of contributing to antibiotic >resistance both in target and non-target organisms? Extension personnel stress cultural control > >16. What amount of public concern has been encountered with the use of >antibiotics as pesticides? If applicable, please provide examples. None > >17. To what degree are you concerned that the use of this pesticide may >result in increased resistance to antibiotics used to treat human >diseases (pathogens) or that the use of these chemicals may increase the >number of human pathogens that are resistant to antibiotics? No edible commodities are generated by FL use of streptomycin > >18. How fast is resistance developing to this pesticide? Bacteria are thought to be resistant but not widely monitored > >19. If pests become resistant to this pesticide, what is the proposed >path forward? Generally controlled with cultural practices

Responder: Mark Mossler
State: PR
Date Requested: Jun 16, 2005
Not Important/Relevant to my state(s)
Response:

Responder: David Ritchie
State: NC
Date Requested: Jun 16, 2005
Response: TO: Steve Toth, Charles Walker, Charlie Meister, Phil Brannen, and Dan Horton FROM: Dave Ritchie RE: Response to questions about oxytetracycline use on peaches. It seems as though this material has reached the radar screen of EPA! Attached are my responses to 19 questions, which are in addition or reduntant to those that I answered a few weeks ago. Charles and Charlie, I though you both may also be interested in my responses to these questions. Charlie, question #15 asks for information about monitoring for resistance. Is there any type of funding in IR-4 for developing such a system that could be used in the Southeast? And possibly including the eastern U.S. peach areas where oxytetracycline and copper are used? Historically, streptomycin and fireblight have generally received more attention than have oxytetracycline and peaches. Regards, Dave -- David (Dave) F. Ritchie Professor and Director of Graduate Programs Department of Plant Pathology North Carolina State University Raleigh, NC 27695-7616 USA Tel: 919.515.6809 FAX: 919.515.7716 ------------------------------- Comments from David F. Ritchie, Dept. Plant Pathology, NC State University, Raleigh, NC – 7 June 2005. Where possible, please provide information for both oxytetracycline and streptomycin. Use: My comments apply only to oxytetracycline use on peaches 1. Approximately how many times per year is this pesticide typically applied? On average my estimate is 6 to 10 applications on peaches at risk – NOT on all peach acreage. 2. What are the typical application rates (as opposed to maximum label rates)? 0.75 to 1.25 lb of formulated product per acre with most at 0.75 to 1.0 lb/A usually in 100 to 125 gal of water per acre. 3. What are typical reapplication intervals (in days)? Intervals are 7 to 14 days and less if weather conditions very favorable. 4. What factors influence the number of times per year this pesticide is applied (i.e., how do growers determine whether or not to apply/reapply)? Frequency and amount of rainfall and the presence of bacterial spot in the orchard. 5. In the last ~15 years, what is the maximum number of times per year this pesticide has been applied? 15-20 times for late season ripening varieties, which in my opinion is excessive and is uncommon anymore. 6. What is the most common application method for this pesticide (e.g., ground spray)? Orchard airblast ground sprayer. 7. If applicable, what precautions are taken to prevent spray drift or off-site pesticide migration? Not spraying when excessively windy. 8. Over the years, has the typical number of applications increased, decreased, or stayed the same? Decreased because there have been attempts to alternate with the use of low rates of copper-containing materials as long as phytotoxicity from copper does not become unacceptable and as a result of cost of material. Also as a result of the use of pre-fruit set copper sprays to reduce or delay an epidemic thus reducing the amount and number of oxytetracycline applications needed post-fruit set. 9. Over the years, have application rates (i.e., number of pounds of active ingredient applied per acre) increased, decreased, or stayed the same? Rates have mostly remained about the same to possibly slightly decreased being driven by weather conditions and disease severity and cost of the product. Target pests: 10. Is this pesticide the only (or one of very few) tools for combating any pests? If so, please list the pests and why alternatives are ineffective. On peaches, the only target is the bacterial pathogen, Xanthomonas arboricola pv. pruni, causal agent of bacterial spot. Oxytetracycline is the only effective product that can be used on peaches after fruit set for bacterial spot control without risk of unacceptable phytotoxicity. Copper-containing materials are very effective against this pathogen but pose a high risk of phytotoxicity when used after fruit set and also could potentially have resistance develop to copper. Although other materials (e.g., biologicals (SERENADE), plant activators (ACTIGARD, phosphites) have been and continue to be evaluated, so far none are as effective as oxytetracycline and copper materials. 11. To what extent do growers rely on this pesticide to combat fire blight and bacterial spot? Oxytetracycline is the chemical around which a bacterial spot management program is designed after fruit set. 12. What are the alternatives for this pesticide (in particular for fire blight, bacterial spot, and any pests identified in question 10)? See answer to #10. 13. Are the alternative products comparable in efficacy and price to this pesticide? At this time, the results suggest that the alternatives are not. Copper materials are the exception, but unacceptable phytotoxicity can be a significant problem. Antibiotic resistance: 14. How do growers react to pests that show resistance to this pesticide? Do they use an alternative product, apply more of this pesticide, or use other methods to manage pests? So far no resistance to oxytetracycline has been detected in the bacterial spot pathogen of peach. 15. What strategies, if any, are currently in place or being developed to monitor and/or reduce the likelihood of contributing to antibiotic resistance both in target and non-target organisms? Reduction in continuous, repeated use of oxytetracyline by using copper materials prior to fruit set (shuck split) and alternate or tank-mix with low rates (0.5 – 1.0 oz metallic copper/A) in sprays applied post-fruit set. I am not aware of any systematic program in place for monitoring for resistance. However, periodically, during each growing seasons, bacterial pathogen samples collected from fields that received oxytetracycline and copper are assayed for decreased sensitivity. With appropriate funding, a system could be relatively easily established to monitor for resistance in both the target and non-target microbes. 16. What amount of public concern has been encountered with the use of antibiotics as pesticides? If applicable, please provide examples. I am not aware of an expression of public concern possibly because of unawareness. 17. To what degree are you concerned that the use of this pesticide may result in increased resistance to antibiotics used to treat human diseases (pathogens) or that the use of these chemicals may increase the number of human pathogens that are resistant to antibiotics? This depends somewhat on how much streptomycin and tetracycline antibiotics are still used in human medicine or resistance to these two antibiotics could cause cross-resistance in more commonly used antibiotics. 18. How fast is resistance developing to this pesticide? Oxytetracycline has been used on peaches for almost 25 years, so far there are no reported or confirmed cases of resistance in the bacterial spot pathogen. In contrast, resistance to streptomycin can be readily selected for in the laboratory. 19. If pests become resistant to this pesticide, what is the proposed path forward? There will be more focus on using copper materials while trying to manage the risks from phytotoxicity. If other alternatives such as biologicals and plant activators show efficacy, even at low levels, strategies will be developed to integrate these into a management program still based greatly on copper. The best long-term solution is use of host resistance. Although host resistance is present, many of these cultivars do not have the best production characteristics and market values. Also, in years when environmental conditions are highly favorable for bacterial spot, resistance is not totally adequate.

Responder: Turner Sutton
State: NC
Date Requested: Jun 16, 2005
Response: Where possible, please provide information for both oxytetracycline and streptomycin. oxytetracycline not registered for us in NC so all answers are for strpetomycin Use: 1. Approximately how many times per year is this pesticide typically applied? 1-4 2. What are the typical application rates (as opposed to maximum label rates)? 0.5 lb/acre 3. What are typical reapplication intervals (in days)? depends on weather - in a favorable year every 4-5 days 4. What factors influence the number of times per year this pesticide is applied (i.e., how do growers determine whether or not to apply/reapply)?favorable weather 5. In the last ~15 years, what is the maximum number of times per year this pesticide has been applied? ???????? 4 rarely more 6. What is the most common application method for this pesticide (e.g., ground spray)? airblast 7. If applicable, what precautions are taken to prevent spray drift or off-site pesticide migration? spraying under still conditions 8. Over the years, has the typical number of applications increased, decreased, or stayed the same? same 9. Over the years, have application rates (i.e., number of pounds of active ingredient applied per acre) increased, decreased, or stayed the same? same Target pests: 10. Is this pesticide the only (or one of very few) tools for combating any pests? If so, please list the pests and why alternatives are ineffective. fire blight (Erwinia amylovora) - there are some biological controls registered but they are generally inconsistent in their performance 11. To what extent do growers rely on this pesticide to combat fire blight and bacterial spot? almost exclusively 12. What are the alternatives for this pesticide (in particular for fire blight, bacterial spot, and any pests identified in question 10)? some biologicals 13. Are the alternative products comparable in efficacy and price to this pesticide? not as efficacious Antibiotic resistance: 14. How do growers react to pests that show resistance to this pesticide? Do they use an alternative product, apply more of this pesticide, or use other methods to manage pests? alternate or combine with broad spectrum products if available 15. What strategies, if any, are currently in place or being developed to monitor and/or reduce the likelihood of contributing to antibiotic resistance both in target and non-target organisms? many growers use information from models to spray, as opposed to a calendar basis, which can significantly reduce the number of sprays in an unfavorable year. 16. What amount of public concern has been encountered with the use of antibiotics as pesticides? If applicable, please provide examples. none, at least in NC 17. To what degree are you concerned that the use of this pesticide may result in increased resistance to antibiotics used to treat human diseases (pathogens) or that the use of these chemicals may increase the number of human pathogens that are resistant to antibiotics? very little 18. How fast is resistance developing to this pesticide? we have no documented evidence of resistance in NC 19. If pests become resistant to this pesticide, what is the proposed path forward? will probably seek a registration for oxytetracycline if other effective products (i.e. biologicals, other chemistries) are not registered. Turner B. Sutton Department of Plant Pathology North Carolina State University

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