Beers, E.

Bret, B.

Lampson, L.

Undetermined

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4. Chemical Control/New ProductsEFFECT OF TIMING AND ADJUVANTS ON LEAFMINER CONTROLWITH SUCCESS™E. Beers, L. Lampson and B. BretWSU-Tree Fruit Research & Extension Center, 1100 N. Western Ave., Wenatchee, WA 98801Tests against western tentiform leafminer were performed from 1995-1998 in an effort todetermine optimum rates, timing, and adjuvant with spinosad (Success). This material wasregisterd for the first time in apples in early 1998. Tests included the current standard, Agri-Mek, and often the previous standard, Vydate.Initial tests performed with an earlier formulation (NAF-144) indicated that rate had littleeffect on performance, but timing was critical (Fig. 3). Applications made when most of thelarvae were in the tissue feeding stage, and had begun to pupate, were the least successful. The 2applications timed for primarily sap-feeding stages provided good control. Tests in 1997explored both rate and the use of an adjuvant (Figs. 1, 4, 2nd generation). In both cases, theaddition of an adjuvant to an intermediate rate provided greatly superior control to spinosadalone. During the 3rd generation, this approach was explored further using different rates of 2adjuvants, oil and Sylgard (Fig. 2). Again the addition of an adjuvant provided superior control,and there appeared to be a (nonsignificant) rate effect when Sylgard or oil was added (Fig. 4).Although 2nd generation is the most typical target for leafminer sprays, a trial against the1st generation was performed in 1998, to check efficacy during approximately the timing forleafrollers (ca. petal fall) (Fig. 5). Performance of all materials tested (including the standard,Agri-Mek) was poor, perhaps due to slightly later than optimum timing. This prompted us torevisit the timing issue for the 2nd generation test (Fig. 6), and try a timing earlier than ourstandard one (ca. 90% sapfeeders, 10% tissuefeeders). The positive effect of an adjuvant wasagain apparent, and the earlier timing appeared to have a slight (nonsignificant) advantage overthe standard timing. A double application at the early and standard timing did not improvecontrol.Our conclusions to date are that the addition of an adjuvant will enhance the activity ofSuccess, and that either oil or Sylgard will suffice. In addition, the timing may be more criticalthan with previous materials, and that even a few days later than optimum may mean thedifference between "Success and failure". Growers are well advised to err on the early side ofapplications, rather than the late side.83NAF-315 0.06 lbNAF-315 0.09 lbNAF-315 0.14 lbNAF-315 0.09+Sylgard 0.25%NAF-315 0.09 +Oil 0.25%Vydate 2 ptAgri-Mek 10 floz +Orchex 0.25%Check0 12 3 4 5 6WTLM Live Mines/leaf (26 Jun)NAF-315 0.09 lbNAF-315 +Sylgard 4 flozNAF-315 +Sylgard 8 flozNAF-315 +Orchex 0.25%NAF-315 +Orchex 1.00%Agri-Mek 10 floz+ Orchex 1%Vydate 2 ptCheckcdcddd12 3 4 5WTLM Live Mines/leaf (13 Aug)Fig. 1.. WTLM 2ndd generation, Milton-Freewater, OR, Fig. 2. WTLM 3rd generation, Milton-Freewater, OR, L.L.Lampson (appl. 19 June 1997. Lampson (applied 6August 1997)NAF-144 25ppmNAF-144 50ppm20 Jun (98-2-0)26 Jun (85-15-0)4 July (21-75-4): Rate EffectTiding EffectWTLM Live Mines/LeafNAF-315 0.06 lbNAF-315 0.09 lbNAF-315 0.14 lbNAF-315 0.09OrchexAgri-MekOrchexCheck12 3 4 5 6WTLM Live Mines/leaf (15 July)Fig. 3.. WTLM 2ndd generation, Milton-Freewater, OR, Fig. 4. WTLM 2nd generation, Brewster, WA E. Beers,E. Beers, (1995); timing in () refer to % sap, tissue, applied 9 July 1997.pupae at time of application.Success 6 fl ozSuccess +Orchex 0.25%Agri-Mek +Orchex 0.25%Comply 40W 5ozCheckab1 2 3WTLM Live Mines/leaf (15 May)Success alone(S)be1 2 3WTLM Live Mines/leaf (1 July)Fig. 5.. WTLM 1stgeneration, Brewster, WAE. Beers Fig. 6. WTLM 2nd generation, Brewster, WA,E. Beers(applied 7May 1998). (application date is E=18June;S=25 June, 1998).84

Effect of timing and adjuvants on leafminer control with Success™

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Effect of timing and adjuvants on leafminer control with Success™

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