I agree with Peter that it's an old term but always took it to mean codling moth sprays, which back in the old days were hard insecticides that killed everything. In Washington most years three were needed, occasionally four. The term covered is also used to numerate the number of days your cover spray application was good for. Could be that one term was the origin of the other. Doesn't seem like the term should apply much anymore since some of the newer insecticides need to be applied weekly. Some growers would be applying eight to ten cover sprays nowdays.
Bill Fleming Montana State University Western Ag Research Center 580 Quast Ln Corvallis, Montana ________________________________ From: apple-crop-boun...@virtualorchard.net [mailto:apple-crop-boun...@virtualorchard.net] On Behalf Of Peter J. Jentsch Sent: Monday, April 11, 2011 2:14 PM To: Apple-crop discussion list Subject: Re: [apple-crop] definitions question: first, second, third cover Greetings Rye, I believe this term is a carry over from a time when pest management applications would 'cover' the commodity in a blanket of spray following the critical petal fall application. This PF event typically occurs at roughly 80% of the petals falling from a variety such as Mcintosh in apple. At this point in time the flowers loose their attractiveness to bees allowing for insecticide pest management to occur. In New York's Hudson Valley, this application of insecticide will control European apple sawfly, plum curculio, the overwintering stage of obliquebanded leafroller, tarnish plant bug, rosy apple aphid, and others, depending on the insecticide used. Typically insecticide applications follow a 10 to 14 day interval called cover sprays or covers for short, depending of course on insecticide longevity and the weather (OP's longer, Bt's shorter). The residual of the previous application carrying over for this interval based on its residual to withstand weathering or hydrolysis, its U.V. stability and so on. These applications then target the same insect (PC for the 1st and possibly 2nd cover), or a different insect species or complex of insects (such as codling moth at 2nd, SJS at 3rd cover; summer generation of OBLR at 4th cover; apple maggot & SJS at 5th -7th cover) at different periods relative to their timing after petal fall. All of which depends on pest management strategies, weather, population density to name but a few of the variables that increase or decreasing the timing interval. Regards, Peter Hello all, I'm looking over pesticide information and I see a lot of references to first cover, second cover and third cover and also references to first cover spray, second cover spray and third cover spray. All references seem to expect the reader to know what that is. Searching the web I found one reference that said second cover is 4-6 weeks after petal fall. Another reference seemed to refer to the number of wet days to get to second cover and that didn't make any sense to me at all. I guess I'm really unclear on what "cover" means in this context. What does the term refer to? What is being covered at these stages and/or what is doing the covering? Or what observation do you make and say "ah! we are reached second cover today!" (same question for first and third.) Also, what is the relationship between "second cover" and "second cover spray"? (same question for first and third) I think I would understand once I understand what second cover is, but my general confusion on the topic leaves me with little confidence in that. I have found references for definitions of some stages such as green tip, pre-pink, pink. But these "cover" stages elude me. Thanks for sharing your expertise! Rye Hefley Future Farmers Marketer So. Cal. Content-Type: text/plain; name="ATT00001..c" Content-Description: ATT00001..c Content-Disposition: attachment; filename="ATT00001..c"; size=224; creation-date="Mon, 11 Apr 2011 15:25:19 GMT"; modification-date="Mon, 11 Apr 2011 15:25:19 GMT" Attachment converted: MacIntosh HD:ATT00001. 84.c (TEXT/ttxt) (0692E256) -- Peter J. Jentsch Senior Extension Associate Department of Entomology Cornell University's Hudson Valley Lab 3357 Rt. 9W; PO box 727 Highland, NY 12528 email: p...@cornell.edu Phone 845-691-7151 Mobile: 845-417-7465 http://www.nysaes.cornell.edu/hudson/faculty.php http://www.nysaes.cornell.edu/ent/faculty/jentsch/
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