I agree with Davids comments and appreciate his straightforward approach. I think all of us who work at public universities make individual choices of how we respond to these situations. The newer you are into the system the more risk you may feel by introducing revolutionary concepts. Part of that is because, appropriately, we face challenges to anything we propose as a part of the vetting of the information we deliver. It is part of the beauty of science. It's not perfect and it has to survive the realities of the alleys of life, natural selection if you will. Sometimes there's collateral damage. I think any of us with a sense of responsibility tries very hard to avoid that kind of impact but it is inherent to what we do. Administrators are much more senistive to the backlash than we are because they are closer to the elected officials. Another form of natural selection. Its all imprecise and imperfect and quite consistent with the way the natural world works, IMHO. Kind o! f ! like the marketplace, I think. Now that I think about it, it's probably a good thing I'm in the latter phases of my career! ";>) And its a shame, but there are fewer and fewer of us all the time.
Bill >Hi, Dave -- > "Intimidation" may by too strong a word, and I certainly have >never felt any sense of intimidation concerning my expression of >opinions or my selection of research projects. However, I think that >all of us are just a bit reluctant to back away from cherished >concepts that we viewed for many years as points of progress toward >common goals (i.e., IPM, minimizing pesticide use, environmental >progress, etc.). As a result, we may be too slow to admit when some >of these strategies no longer work as intended. I probably should >not have use the PC terminology to express this concern, but there is >some of that involved. > Ultimately, there can be little doubt that universities are >backing away from the kind of applied research that is needed to >address complex problems in agriculture. That fact is clearly >illustrated by recognizing that Andrew Landers' program is perhaps >the only university-supported program in northeastern United States >that deals with issues of spray deposition despite the fact that >virtually all other research on agricultural pest controls (whether >biological, biorational, or traditional pesticides) are ultimately >dependent on effective methods for getting the "pesticide" applied to >the target. > > >> I think public universities are the locus of origin and >>propagation of much that has become "politically correct" in >>American culture, yet I am surprised by the suggestion >>(at the end of Dave Rosenberger's useful observations) that unspoken >>intimidation may now influence the content of university >>publications on spray recommendations. >>There could be no enterprise in which unbiased science is more >>essential than in its application to commercial tree-fruit culture. >> >>David Kollas >>Kollas Orchard >>Tolland, CT >> >>On Jan 16, 2010, at 11:45 AM, Dave Rosenberger wrote: >> >>> Tree-row volume is a complex subject that always generates >>>widely divergent reactions. I'll add my personal perspectives to >>>further muddy the water. >>> First, as I recall, the TRV concept was introduced by >>>horticulturists looking for a way to reduce variability in results >>>when they applied chemical thinners, and it helped them to meet >>>that objective. However, sprays applied to adjust crop load are >>>different than pest control sprays because, with chemical thinners, >>>there are significant economic penalties both for applying too much >>>and for applying too little. With pest control sprays, you may pay >>>a bit extra for the pesticides when products are over-applied, but >>>you lose MUCH more if you under-apply and have a control failure. >>>Thus, the risk-benefit ratio for implementing TRV changes >>>significantly when one moves from thinning sprays to pesticide >>>sprays unless one assigns high values to the social merits >>>minimizing pesticide use, etc. >>> Nevertheless, TRV worked pretty well for most pesticides when >>>it was first introduced. I think that to some extent, this occurred >>>because during the 1960s and 1970s we were in the habit of almost >>>always applying pesticides at far higher rates than were generally >>>needed. I recall being told at the start of my career in the 1970s >>>that as scientists we needed to test products under the highest >>>inoculum levels possible so as to arrive at generalized >>>recommendations that would always work on commercial farms no >>>matter how dire the situation. Given those conditions, applying >>>pesticides with TRV rates involved very little risk because the >>>high rates that we were using as a base allowed plenty of room for >>>error without risk of control failures. >>> Several big changes over the past 30 years have made the >>>generalized formulas for TRV less reliable. Apple production >>>statistics for NY indicate that over the past 30 years we have >>>doubled production per acre, and at the same time we have probably >>>reduced tree size by at least 50% if not more. Put those two >>>together, and you will realize that we are now growing apples at >>>least four times closer together on the trees than was the case >>>when TRV was introduced. I'm not certain how fruit-to-leaf ratios >>>differ between old standard trees and trees on M.9, but I suspect >>>that we still need nearly as many leaves/fruit as we did 30 years >>>ago, so we are probably growing our leaves 4 times as close >>>together as we previously did. This creates problems for spray >>>coverage. When I look at high-producing orchards on M.9 rootstock >>>and envision the tree row as a two-dimensional plane, I see many >>>areas in the canopy that look like solid walls of fruit touching >>>one another with additional fruit located behind the front wall and >>>with additional leaves and fruit on the other side of the canopy. >>>The only way to get enough product deposited on the back sides of >>>the fruit wall is to over-spray the front side and hope that enough >>>fine particles are blown around to the back side or that the >>>chemical will redistribute with rains. >>> To take Jonathan's initial analogy of spraying houses of >>>different sizes, I would suggest that we can envision changes in >>>canopy/fruit density as follows: Assume the 2500 square foot house >>>has exactly the same layout as the 5000 square foot house, but all >>>of the studs are just twice as close together in the smaller house. >>>The houses are all framed up, but have no siding or wallboard >>>covering the studs. Now you must drive down the street and spray >>>the houses so that you have complete paint coverage over all >>>surfaces on the interior studs in both houses. I suspect that you >>>would find that you need nearly as much paint for the small house >>>as for the larger house, in part because it will be more difficult >>>to get the paint to penetrate to the interior of the smaller house >>>with its more closely spaced studs. >>> Another aspect of TRV that has always bothered me is the >>>assumption that the ratio of on-target versus off-target spray >>>deposition is equal for all tree sizes. I suspect that for smaller >>>trees, especially in young orchards where trees have not yet filled >>>their spaces, we actually end up with more spray on the ground than >>>on the trees. To go back to the house painting analogy, the >>>difference in paint required might be less than initially expected >>>if the paint is applied using a sprayer traveling at a set speed in >>>front of the houses. The smaller house will just end up with more >>>paint on the lawn! Using smart sprayer to turn off the nozzles >>>between trees can help, but we are still using really crude methods >>>to get pesticides deposited on trees. It seems logical that >>>differences in deposition efficiency could be so huge as to negate >>>the validity of TRV calculations. >>> Another major concern that I have about TRV is that, for most >>>of the fungicides introduced in the past 20 years, application of >>>low rates is known to speed selection for resistance. In fact, I >>>am aware of several cases in NY where I am convinced that using SI >>>fungicides at TRV rates contributed to rapid development of >>>resistance to SI fungicides. This concern about resistance >>>development is one reason that some labels have statements >>>indicating a legal minimum rate/A that must be applied. >>>(Personally, I don't like to see minimum rate/A statements on >>>labels, but I can understand the rationale for having them.) >>> Using reduced rates with new products is especially risky. >>>Pesticide companies have significant incentives for labeling >>>products at the lowest possible rate per acre that will be >>>effective. For most products, I suspect that product pricing is >>>based on "willingness to pay" rather than on actual costs for >>>making the product. Thus, if my new product is so good compared to >>>competing products that growers will likely pay $35/A for it, then >>>I can maximize profits by keeping the application rate just above >>>the breaking point because I'm going to get the same income >>>regardless of whether the product is labeled at 1 oz/A or at 3 >>>oz/A. Labeling the product at lower rates also reduces the >>>contribution of pesticide residues on apples to my risk cup, so I >>>can label my product on more different crops. As a result of these >>>factors, there is much less room for error in using new products >>>compared to older products like Guthion, Captan, and mancozeb >>>fungicides that seemed to work well with TRV. >>> In summary, I still believe that TRV can be useful if it is >>>done carefully, and I like Dave Kollas's suggestion of actually >>>checking with water to determine what is required as a dilute base >>>in your own orchards. Most growers, however, will not have the >>>time or patience to do that for blocks of different sizes. Thus, >>>for the majority of apple growers, and especially when using newer >>>products, the safest bet will be to apply the recommended amount of >>>product/A regardless of tree size. That suggestion runs counter to >>>IPM philosophy and initially may seem illogical vis-a-vis >>>minimizing pesticide use. However, as outlined above, I think that >>>we have good scientific reasons for questioning the validity of the >>>TRV formulas that were developed 30 years ago, but it is not >>>"politically correct" to remove TRV recommendations from university >>>publications. (Uh-Oh! perhaps that last statement went a bit too >>>far?) >>> >>> >>>>Lots of input on this one Jonathan. It seems that some labels say >>>>not to go below a certain rate per acre. I am aware of at least >>>>one case where a pyrethroid failed to control apple maggot. I >>>>agree that the OPs give more room for error. It looks like pest >>>>management will get much more precise as we get into "softer" >>>>materials in terms of timing, monitoring and rates. >>>> >>>>Art Kelly >>>>Kelly Orchards >>>>Acton, ME >>> >>>-- >>>************************************************************** Dave >>>Rosenberger >>>Professor of Plant Pathology Office: 845-691-7231 >>>Cornell University's Hudson Valley Lab Fax: 845-691-2719 >>>P.O. Box 727, Highland, NY 12528 Cell: 845-594-3060 >>> http://www.nysaes.cornell.edu/pp/faculty/rosenberger/ >>> >>> >>> >>>-------------------------------------------------------------------------- >>> >>>The 'Apple-Crop' LISTSERV is sponsored by the Virtual Orchard >>><http://www.virtualorchard.net> and managed by Win Cowgill and Jon >>>Clements <webmas...@virtualorchard.net>. >>> >>>Apple-Crop is not moderated. Therefore, the statements do not >>>represent "official" opinions and the Virtual Orchard takes no >>>responsibility for the content. >>> >>> >>> >>> >> >> >> >>-------------------------------------------------------------------------- >> >>The 'Apple-Crop' LISTSERV is sponsored by the Virtual >>Orchard<http://www.virtualorchard.net> and managed by Win Cowgill >>and JonClements <webmas...@virtualorchard.net>. >> >>Apple-Crop is not moderated. Therefore, the statements do not >>represent"official" opinions and the Virtual Orchard takes no >>responsibility forthe content. > > >-- >************************************************************** >Dave Rosenberger >Professor of Plant Pathology Office: 845-691-7231 >Cornell University's Hudson Valley Lab Fax: 845-691-2719 >P.O. Box 727, Highland, NY 12528 Cell: 845-594-3060 > http://www.nysaes.cornell.edu/pp/faculty/rosenberger/ > > > >-------------------------------------------------------------------------- > >The 'Apple-Crop' LISTSERV is sponsored by the Virtual Orchard ><http://www.virtualorchard.net> and managed by Win Cowgill and Jon >Clements <webmas...@virtualorchard.net>. > >Apple-Crop is not moderated. Therefore, the statements do not represent >"official" opinions and the Virtual Orchard takes no responsibility for >the content. > > > > > William H Shoemaker, UI-Crop Sciences Sr Research Specialist, Food Crops St Charles Horticulture Research Center 535 Randall Road St Charles, IL 60174 630-584-7254; FAX-584-4610 -------------------------------------------------------------------------- The 'Apple-Crop' LISTSERV is sponsored by the Virtual Orchard <http://www.virtualorchard.net> and managed by Win Cowgill and Jon Clements <webmas...@virtualorchard.net>. Apple-Crop is not moderated. Therefore, the statements do not represent "official" opinions and the Virtual Orchard takes no responsibility for the content.
