Information Requests Monitoring System

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Request ID: 158
Request From: Steve Toth
Date Requested: Jun 01, 2006
Request: Please note the following request for information regarding copper rates on selected crops. Please circulate to the experts in your respective states/territories and submit any responses to the Southern Region IPM Center Information Response Monitoring System by Friday, June 9, 2006. (This is a much easier request than past copper information requests) Thanks. Steve Toth ------------------------------------------------------------------ Attached is a cover letter and a table from EPA covering the crops that they have perceived as the heaviest users of the coppers. It is critical that each of you review these Maximum application rates, the Maximum seasonal rates and the Minimum re-treatment intervals. Do these possible rates and restrictions fit your individual crop use patterns? While we do need response from the crops included on the table we also need to hear about any cropping system that does not find the range of rates and restrictions amenable to their use patterns. Please note that the highest rates which are for Filbert(Hazelnut) in Oregon and Washington should be viewed as special case and the general range of application rates should be considered with it omitted. While your comment should go to the CSTF c/o Ron Landis, rlandis@landisintl.com, please copy to me. Please be aware that the Agency is requesting a rapid turn around for this response; I know that for many of you this is a very busy time but please try to fit this review and response into your schedules, particularly if you see that any of the rates or restrictions on retreatment intervals will constrain your use of copper to manage disease problems in your cropping systems. The Agency has requested that responses be in by June 9. If there are those that you believe are not on this master list or that you think should review this table, please forward it. If there are any of you who are seeing this via a third party please be sure to include you phone number in your response so that I may add you to my coppers master list. Finally please feel free to call or email me if you have any questions about this mailing. Ted Rogers Biologist, Senior Policy Analyst USDA Office of Pest Management Policy 202-720-3846 trogers@ars.usda.gov http://www.ars.usda.gov/opmp/

Responses
Responder: Mark Mossler
State: VI
Date Requested: Jun 02, 2006
Response: See comments from FL

Responder: Mark Mossler
State: PR
Date Requested: Jun 02, 2006
Response: See comments from FL

Responder: Mark Mossler
State: FL
Date Requested: Jun 02, 2006
Response: After reviewing the metallic copper values for citrus, pepper, tomato, and strawberry, the values are all at the limit of what we need in FL and the Caribbean. The only oversight was the omission of lime from the list of citrus species. The additional concern was that cross formulation labeling would be placed on copper products indicating a total amount of metallic copper per season or year.

Responder: Brian Cummins
State: TX
Date Requested: Jun 05, 2006
Response: Copper fungicides are used by organic producers and by some commercial producers in East Texas. I recommend copper containing fungicides for control of diseases in apples, peaches, certain vegetable crops and to control ball moss and lichens in ornamental trees.

Responder: Ples Spradley
State: AR
Date Requested: Jun 05, 2006
Response: The following response is from Dr. John Clark, Professor - Horticulture, Univ. of Arkansas: I am quite far away from being up on spray compounds now since I have been away from managing this at Clarksville for some years. I do know that coppers are important to peaches, grapes and brambles but not sure on others. Interesting is a parasitic alga that is causing trouble further south on blackberries and copper is likely the best bet on that. have not see in Arkansas yet tho.

Responder: Scott Strawn
State: TX
Date Requested: Jun 06, 2006
Response:

Responder: Joseph Daniel
State: TX
Date Requested: Jun 06, 2006
Response: These materials are helpful in managing bacterial disease. They are not heavely used but would not want to lose them.

Responder: David Ritchie
State: NC
Date Requested: Jun 11, 2006
Response: June 2, 2006 TO: Dr. Ron Landis, Chair CSTF FROM: Dr. David Ritchie, Plant Pathology, NC State University, Raleigh, NC RE: Copper Use Rates/Minimum Retreatment Intervals for Peaches First, listed maximum rates of metallic copper equivalent (MCE, Cu2+) for both the ‘per application’ and ‘maximum seasonal’ are very appropriate for use on eastern US peaches and particularly in the southeast for bacterial spot management and other diseases (eg. leaf curl). However, the ‘bloom/growing season’ rate should range as low as 0.05 lb (0.80 oz) MCE per acre. If the grower is restricted to no less than 0.25 lb MCE per acre, unacceptable phytotoxicity occurs when applied at certain post-bloom tree growth stages. Thus, I would prefer the range for ‘bloom/growing season’ be 0.05 – 1.5 lb MCE per acre per application. The 1.5 lb rate could probably be reduced to 1.0 lb MCE per acre if this helps in other parts of the uses; thus making the range 0.05 – 1.0 lb MCE per acre per application. Once petal-fall starts an application greater than 0.25 lb MCE per acre usually causes unacceptable phytotoxicity. Second, my greatest concern is with the minimum retreatment intervals. The ‘dormant/late- dormant’ 30 days interval will NOT work for successfully managing bacterial spot of peaches. This interval needs to be a maximum of 7 days; 5 days would be even better. Multiple applications of copper materials from late dormant through early bloom are critical if bacterial spot is to be managed. In a season when environmental conditions (frequent periods of precipitation) are highly favorable for bacterial spot, 3 to 5 copper applications with one or two at a 5 to 7 interval may be needed prior to full-bloom. This also is the time when copper can be applied to peaches with the least risk for unacceptable phytotoxicity. A rigorous spray program pre-bloom can reduce the number of applications needed post-bloom (which are usually not effective if the disease was allowed to infect emerging plant tissues) and its proper use determines if the disease will be successfully managed. The extended retreatment intervals make no sense for the use of a metal-containing material such as copper. Because the metal, copper, does not breakdown, it would seem that the minimum time (days) interval between applications is irrelevant and should be dictated by the disease epidemiology. What should be important environmentally is the total MCE applied regardless of the interval between applications. The reason for multiple applications is ‘wash-off’ as dictated by precipitation and to protect newly emerging plant tissues (eg leaves and fruit). The use of copper on peaches for management of bacterial spot is not based so much on application of large quantities of copper at anyone time (peach foliage will not tolerate it), but on the use of rates that are greatly reduced once the initial dormant/late-dormant application, which still does not exceed 2.0 to 2.5 lb MCE per acre, is applied. For bacterial spot management, the total dormant/late-dormant through early bloom quantity of copper does not need to exceed 6.0 lb MCE per acre. The total post-bloom (starting with late petal-fall) quantity used also does not need to exceed 1.5 lb MCE per acre. As stated previously, peach foliage does not tolerate copper well and this acts as a ‘quantity used regulator’. C: Ted Rogers, USDA Office of Pest Management Policy Phil Brannen, Extension Fruit Pathology, University of Georgia Steve Toth, Associate Director – Regulatory Issues, SRIPMC

Responder: Barbara Shew
State: NC
Date Requested: Jun 11, 2006
Response: Copper use on peanut is not great. Labeled rates range from 0.35 to 1.2 lb as Cu++. According to a quick survey of agents, perhaps 5 to 10% of North Carolina growers would apply a copper compound once or twice a season. No one gave me a typical rate. For an organic study last year, we used 0.7 lb Cu++ per application x 5 applications at 14 day intervals. Under severe pressure, it might take one or two more applications, but I don't have enough experience with it to be sure. I hope we can maintain a copper label on peanuts for use in organic production, assuming we can get this industry off the ground. Barbara Shew Department of Plant Pathology North Carolina State University

Responder: Todd Swift
State: TX
Date Requested: Jun 13, 2006
Response: Copper fungicides are recommended extensively in our area for control of ball moss and lichens in Live oak trees. They are also used in commercial and homeowers gardens.

Responder: Mani Skaria
State: TX
Date Requested: Jun 22, 2006
Response: Copper use on citrus in Texas is far below the rate given in the table. The most important disease that citrus growers try to control with copper in Texas is greasy spot caused by Mycosphaerella citri. Copper is only one of the products used for greasy spot control. Survey efforts are underway for citrus canker and citrus greening diseases in the Lower Rio Grande Valley and elsewhere in Texas. If/when these diseases are detected, the need for copper sprays will increase. At that time it may require to exceed the copper use beyond what is listed in the table because Texas will be trying to eradicate an exotic pathogen(s).

Responder: Mark Black
State: TX
Date Requested: Jun 30, 2006
Response: I am comfortable with the maximum rates per application. However, I feel that the number of applications used in the western half of Texas are lower than the number implied by the seasonal rates column. I suggest Maximum seasonal rates (lbs Cu2+_/Ac) are approximately 7 for tomato, 5 for pepper, 7 for strawberry, 7 for apple, and 3 for grape. I apologize for the delay in responding--it's been hectic here this summer of drought. Best regards.

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