Scaffolds 6/5/00

Moths of the obliquebanded leafroller started flying in the Hudson Valley over the weekend (official first catch is today, June 5, because that's when the traps were checked) and have not yet shown up in traps in western N.Y., which pretty much puts us about back on a more normal schedule for insect activity, although by way of some quick-change alternations of hot and cold stretches. First hatch is generally assumed to occur about 360 DD (base 43°F) after the flight starts, and we'll be updating you each week with values for Highland and Geneva. This brings us quite naturally to the perennial question of how best to approach management of OBLR populations this year, so a brief synopsis of last year's research efficacy trials might be in order.

Pesticide control programs for the first summer brood of OBLR were conducted in two Wayne Co. orchards in 1999, one of them an Empire/Cortland mix and the other Empire/Idareds. All sprays were applied using three of the following timings after the beginning of summer adult flight on 6/5: Peak Flight (6/16), First Hatch (6/24), 40% Hatch (6/30) and "cover sprays" at various timings: 7/7, 7/14, 7/21, and 7/28.

• Three products were compared at 6/16, 6/30, and 7/14: Confirm 2F, Calypso 70WG (a "2nd generation" neonicotine like Provado), and Intrepid (a "second generation" molt accelerating compound like Confirm).

• Two products were tested starting at 6/30, then again at 7/14 and 7/28: Spintor 2SC and Lorsban 75WG.

• A large number of other new products were tested at 6/24, 7/7, and 7/21: Crymax WDG and Dipel DF (both B.t. materials), Warrior (lambda cyhalothrin, a pyrethroid), Avaunt (indoxacarb, a carbamate), Proclaim (emamectin benzoate, an avermectin), as well as Asana, Lorsban 50WS and SpinTor.

OBLR infestations were considerably lighter in the Empire/Idared orchard than in the Empire/Cortlands, and the trees there were also smaller in size, which allowed considerably better spray coverage. Terminal infestations in July were quite high in all plots, and none of the treatments were particularly effective in controlling larvae in the growing terminals.

Crymax was no more effective than the Dipel standard in preventing fruit damage. The most effective materials were Confirm, Intrepid, and Proclaim. Higher rates of both Intrepid and Proclaim gave better results than respective lower rates. Both tests involving Spintor were comparable and as effective as the standards of Dipel, Asana, and Lorsban. Warrior, Calypso, and Avaunt offered no improvement over these standards.

Because of Confirm's availability against the overwintered brood of OBLR for the first time this year, a number of plots were set out last month to test the effectiveness of petal fall sprays against the traditionally larger larvae present at that time. Comparisons were made in a series of sites around western N.Y. and terminal infestations were recorded by evaluating 1000 terminals per treatment last week (5/31—6/2). The results, which follow, show that the relative effectiveness of Confirm is somewhat variable, being quite good in some orchards and not particularly evident in others. Intrepid may be somewhat better than Confirm, but not all of those plots have been evaluated yet:

Our recommendations for OBLR management this year continue to follow along lines similar to those we have given previously. Most materials available should be at their maximum potential effectiveness when used 2—3 times (in moderate or high pressure orchards, respectively) against the first summer brood larvae. Applications in a 3-spray program should be made at times approximately corresponding to periods of first hatch, mid-hatch, and 2 weeks after mid-hatch. In orchards where SpinTor is being used, the inclusion of a low rate of an adjuvant such as LI-700 or Sil-Wet is recommended. As always, standard materials such as Lorsban and Asana are likely to work better against populations not having a history of extensive exposure to them.

OBLR --THE UNAUTHORIZED BIOGRAPHY