March 17, 2003 Volume 12 No.1 Update on Pest Management and Crop Development
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JOY IN MUDVILLE
(Art Agnello, Entomology, Geneva)
No doubt most of us have seen quite enough winter weather by now, and so were appreciative of last weekend's warm-up, however much a mess it made of the ground. Despite the fact that we're certain not to be completely finished with temperatures on the leaner side of 50, it's difficult to resist the thought that we may finally have repaid much of the winter deficit that has accumulated in recent years.
The mailing list for this newsletter awakens to re-define itself each spring. Delivery of the hard copy to subscribers failing to return the re-subscription card will cease after some famously arbitrary period of time. I also post it to the CCE Tree Fruit Discussion Group BB, a list-serve, at:
As always, we are happy to consider contributions (particularly from N.Y. sources) in the form of articles on topics in any of the fruit crop protection or crop production areas, as well as N.Y. field observations, trap data, etc. We generally do not send the mailed version of this newsletter to growers, homeowners, or other private individuals not having some fruit extension, commercial, university or governmental affiliation, as the extension superstructure that pays the bills would rather that audience obtain this information from their local Cornell Cooperative Extension programs. Unless things get too out of hand, the e-mail version will be sent to anyone who requests it; just don't ask how this squares with all that stuff in the previous sentence.
Rumor has it that the 2003 Pest Management Guidelines for Commercial Tree-Fruit Production has actually made it through the black hole of the printshop and found its way into the hands of many growers (although the people who actually wrote the book have yet to see a copy). Moreover, an online version of the new edition is available as a series of pdf files that can be printed off, from:
We're also in the process of updating the html-format version, which contains the appropriate interactive links to all of our other online resources. Incidentally, these can all be accessed at the still-evolving Cornell fruit web page: http://www.fruit.cornell.edu/
That said, it's not too early to point out a couple of corrections to this masterwork that have reached my attention. Probably these will be the ONLY errors in the entire book:
p. 43, Bacillus thuringiensis formulations: registrant of Agree WG is now known as "Certis".
p. 65, Table 14 Abbreviations: WNY = Western New York
p. 218, Table 53: REI for both Lorsban formulations should be 96 hours
PRODUCT REGISTRATION UPDATE
(Art Agnello, Entomology, Geneva)
Labels in Limbo
Time for the annual laundry list of our progress in coming up to speed with the rest of the country, according to the most recent bits of news we've received from those in the know about the status of those elusive state registrations:
Acramite - This product received a NY registration last fall, so it is already available. Acramite (bifenazate) is a carbazate that acts as a contact acaricide against both the motile stages of mites and the larvae and nymphs that hatch from treated eggs. Because this represents a new class of chemistry, no cross-resistance to this material has been demonstrated versus other currently used acaricides. It is effective against both European red mite and twospotted spider mite, exhibiting a rapid knockdown of contacted motile forms and a relatively long residual efficacy period. For greatest efficacy, the manufacturer strongly recommends that water hardness be reduced with an ammonium sulfate product (e.g., Choice, Quest) prior to adding the product and any surfactant. It is labeled in New York for use on apples, pears, peaches, nectarines, plums and prunes. Only one application per year is permitted. It is moderately toxic to honeybees upon direct contact, but low in toxicity by foliar residue; it therefore has a moderate bee-poisoning hazard. Formulation available and EPA registration number: Acramite (Crompton) 50WS: 400-503.
Actara - Another johnny-come-lately registration, Actara was labeled for use in NY last June, considerably after its recommended use timing of pink to petal fall. Actara has shown efficacy and is labeled for the control of plum curculio, rosy apple and green aphids, tarnished plant bug, European apple sawfly, Comstock mealybug, and mullein plant bug. Although this was a much-anticipated registration by the fruit industry in this state, the delay in this decision effectively carried us past the recommended use timing of pink to petal fall, so most growers have not had occasion to use it yet. The NY label carries the further restriction of one application per season, which serves to render the product's efficacy to essentially half of its optimum potential. Efforts are under way to address this label inadequacy, although chances of a full label are uncertain at this point. Actara has a 12-hr REI and a 35-day PHI.
Entrust - This is a recently labeled organically approved formulation of spinosad, the same a.i. as in Spintor, with a similar activity spectrum against pests of pome and stone fruits (leafrollers, internal worms, apple maggot and cherry fruit fly suppression, thrips, leafminers). Available now for use in NY.
Intrepid - This is the more-active replacement successor to Confirm, which we finally have a label for, just as it's due to be phased out of the tree fruit market. Dow has the state registration packet submitted to DEC, but they're apparently waiting to get additional information on the product (reports that are called "Data Evaluation Records", or DER's) from the EPA, who naturally are slow to respond since they feel they've already done their job by giving it a federal label. If it doesn't proceed smoothly, some timely arrangement may still be reached for this season's use; we'll keep you posted.
Assail - A new member of the neonicotinoid group of insecticides (which includes Provado and Actara), this selective product has activity on aphids, leafminers, leafhoppers, and psylla, but more importantly, codling moth and oriental fruit moth are also susceptible. Its NY registration status is similar to Intrepid's, only perhaps somewhat dimmer, as it's newer on the scene. These are the kinds of situations where being on a first-name basis with a sympathetic legislator could help to expedite the process.
Isomate-L - This is the pheromone tie formulation for mating disruption of lesser peachtree borer, which we erroneously thought had already been labeled in NY, but somehow slipped through the net. The package is being reviewed by DEC, and a decision is expected in time for its use in late May.
Warrior - A new synthetic pyrethroid (lambda-cyhalothrin) intended for use on pome fruits and stone fruits. Registration in NY is anticipated sometime in May.
IT DON'T MEAN A THING IF IT AIN'T GOT TO SPRING
(Art Agnello, Entomology, Geneva)
Just a word here about the anticipated effects of a really cold winter on insect and mite populations in this region. First, we most frequently get questions about the winter weather pattern's effect on ERM eggs, in terms of their ability to either tolerate exceptionally cold temperatures, or to take advantage of unusually mild weather. The fact is that there is always some winter mortality of ERM eggs, that it can be quite variable (ranging from perhaps 15% to nearly 60% in severe cases), and that it is dependent on many different factors, such as orchard micro-habitat and air drainage, amount of snow cover, and genetic characteristics of local populations, in addition to simple raw temperature readings. One study conducted in NY after the extremely cold winter of 1956-57 showed that ERM hatch was cut drastically (to 1-20% of normal) in western NY after a 3-5-day period in the -23 to -28°F range, but that hatch reduction was not uniformly this severe in the Lake Champlain growing region following the same temperature pattern. These results suggest that the eggs in that district may have been conditioned to withstand lower winter temperatures than in warmer parts of the state. The long-term average winter minimum in Peru is approximately -22°F, whereas in the Geneva area it ranges from -10 to -15°F.
In general, a severely cold winter can reduce the viability of the eggs that are present in the spring, but favorable developmental weather early in the season can easily compensate for a small founding egg population, whereas a cold, wet and extended April and May can serve as effectively to retard mite development as would a good early season spray program.
Similarly, regardless of the cold winter, which generally only predicts higher overwintering mortality of things like mite eggs and small OBLR larvae, the fate of the season's insect populations probably depends more on what kind of early spring weather we end up having. Observations over the years support the conclusion that the growth of most prebloom arthropod populations is pretty much determined for the first half of the season by spring weather patterns.
European red mite, rosy apple aphid, spotted tentiform leafminer, tarnished plant bug, San Jose scale, and mullein bugs are only the most obvious of the species that suffer from a cold, wet, rainy and windy (in other words, typical) spring. They may be slowed considerably until the summer generations, or they might fail to show up at all in some cases. Conversely, a warm, dry, quick spring can result in nearly spontaneous generation of most of these pests. After the petal fall period, the rate of heat unit (Degree Days) accumulation is a primary factor in the duration of plum curculio oviposition (hotter = shorter period) and the speed of summer mite population growth. This latter case is especially crucial, as the first summer ERM eggs are generally hatching in June so the population is already primed to expand; additionally, the trees are particularly susceptible to foliar feeding stress, so a failure to act against a threshold-level infestation early will result in a long, hard battle for the rest of the summer. As usual, we'll be publishing accumulated DD values for various spots around the state, together with advisories relating to timely control interventions where appropriate.
This material is based upon work supported by Smith Lever funds from the Cooperative State Research, Education, and Extension Service, U.S. Department of Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.
Scaffolds is published weekly from March to September by Cornell University -- NYS Agricultural Experiment Station (Geneva), and Ithaca -- with the assistance of Cornell Cooperative Extension. New York field reports welcomed. Send submissions by 3 p.m. Monday to:
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