Progress Report of Lettuce Field Tests in 2010 of Select Insecticides

Transcription

1 Progress Report of Lettuce Field Tests in 2010 of Select Insecticides Vonny Brlow University of Cliforni, Agriculturl nd Nturl Resources Blythe, CA Abstrct The projects completed this pst summer sought to evlute the efficcy of DuPont Corgen s 2 bnd over the top t plnting, Byer CropScience Movento, Dow AgroSciences Rdint SC, Byer CropScience Synpse WG, nd DuPont Avunt insecticides ginst the industry stndrd use of DuPont Corgen for the mngement of the top pests of Southern Cliforni lettuce(s); the silverlef whitefly, Bemisi rgentifolii Bellows & Perring (Hemipter: Aleyrodide) nd Lepidopter complex of rmyworms, cbbge loopers nd imported cbbgeworms (Lepidopter). Evlution of Corgen used s n environmentl low risk ppliction vi soil ppliction during plnting mkes it idel s prt of n IPM system for mnging insects like the silverlef whitefly in dmge sensitive crops like lefy greens. The lck of differences in tretments nd the untreted controls reflects the impct tht light insect pressure hs during the trnsition from the hottest prt of the yer to the coolest in the Plo Verde Vlley. Adult silverlef whiteflies popultions seemed to plteu between 11/10-11/18 nd were found only in low numbers cross ll tretments including the un-treted control. Relisticlly it is difficult to stte tht the tretments were unsuccessful since pest pressure ws reltively light for evlution of select insecticide formultions. Project Title Effect of Selected Insecticides for Whitefly, Bemisi tbci nd Lepidopter Mngement on Lefy Greens Principl investigtor: Vonny M. Brlow Summry The lck of differences in tretments nd the untreted controls reflects the impct tht light insect pressure hs during the trnsition from the hottest prt of the yer to the coolest in the Plo Verde Vlley. Adult silverlef whiteflies popultions seemed to plteu between 11/10-11/18 nd were found only in low numbers cross ll tretments including the un-treted control. Relisticlly it is difficult to stte tht the tretments were unsuccessful since pest pressure ws reltively light for evlution of select insecticide formultions. Min Body: Project Title Effect of Selected Insecticides for Whitefly, Bemisi tbci nd Lepidopter Mngement on Lefy Greens Principl investigtor: Vonny M. Brlow

2 The objective: Assess the efficcy of insecticide use for whitefly nd Lepidopter mngement on lefy green lettuce, ssess the comptibility of Corgen s protectnt when incorported 2 t plnting nd/or s 2 bnd ppliction t plnting. Evlution of Corgen s environmentl low risk ppliction vi soil ppliction during plnting mkes it idel s prt of n IPM system for mnging insects like the silverlef whitelfy in dmge sensitive crops like lefy greens. Mterils & Methods Reserch plots were estblished on University of Cliforni controlled lnd for evlution of select insecticides for mngement of silverlef whitefly (Corgen, Movento ) nd lepidopter lrve (Avunt, Synpse, Rdint ) (Fig. 1) ginst un-treted controls. Experimentl plots were estblished into direct seeded double row beds of seprtely plnted hed (Iceberg) lettuce cv. Experimentl 1221 nd erly green (lef) Romin cv. Del Sol. Rised beds were 3.33 ft (40 ) on center nd 300 ft. long with individul tretment rows bordered by untreted rows to minimize spry interctions between tretments (Fig. 2). Tretments in ech of the lettuce vrieties used were rndomly ssigned nd blocked by repliction (RCBD) with 4 replictions used. Individul tretment plots consisted of 13.1 ft. x 3.33 ft. ( A). Corgen tretments were either pplied s 2 in. bnded tretment over the top of the seed line or s sub-surfce soil injection (SSI). The SSI Corgen tretment ws trctor-pplied prior to plnting with totl H 2 O volume of 1 gl./300 ft. of rised bed with 1 min. 18 sec. ppliction time/row. The surfce bnded (SB) tretment ws pplied s 2 in. wide bnd directly over the seed line immeditely fter seed plcement with bck-pck spryer fitted with cone nozzle delivering gl. H 2 O/52.4 ft./lettuce vriety. Folir pplictions were mde with CO 2 pressurized bck-pck spryer using 3-nozzel hnd-held spry boom fitted with TXVS-8 ConeJet nozzles. Folir pplictions were mde 7 d for totl of 8 pplictions on Oct. 18, 25, Nov. 2, 8, 15, 24, 29, Dec. 6. End of seson dmge ssessments to determine tretment efficcy ws mde on Dec. 21. All mrketble lettuce heds were hrvested in ech of the 13.1 ft. plots nd processed seprtely. Lettuce heds were smpled destructively to detect lrvl tunnels nd live worms. Dt ws trnsformed (log + 0.5) prior to nlyzing using 1-wy nlysis of vrince (ANOVA) followed by mens seprtion test (P<0.05). Results & Discussion Whitefly pressure ws high in djcent fields prior to the strt of these lettuce efficcy trils nd then dropped with the onset of cooler tempertures. Cooler effectively suppressed whitefly popultions for the durtion of these experiments (Figs. 3 & 4). Whitefly popultions remined low nd never exceeded n un-treted control men of (± SD) of 0.28 ± 0.06 whiteflies. As result, tretment yields were reltively unffected in the green (lef) Romin cv. Del Sol trils with mrketble yields not significntly different (P = 0.062) mong tretments including the un-treted controls (Fig. 3). End-of-seson yield nd weight ssessments showed no significnt difference similrly mong tretments (P = 0.25 nd P = 0.15 respectively) (Fig. 5). Lepidopter counts essentilly equled 0.0 over the course of the seson but lepidopteron dmged green lef heds were detected t the end-of-seson ssessments (Fig. 6). Yields nd weights of lepidopteron dmged green lef heds were not found significntly different mong tretments including the un-treted controls (P = 0.50 nd P = 0.58 respectively) (Fig.6). Plots of hed (Iceberg) lettuce cv hd fewer whiteflies with the un-treted control men of 0.08 ± 0.02 when compred to plots of green (lef) Romin cv. Del Sol (Fig. 4). Whitefly counts

3 over the course of the growing seson were not significntly different mong tretments nd the un-treted controls (P = 0.95) (Tble 1). This is reflected similrly in the lck of significnt differences in mrketble yields nd weights mong the tretments nd the un-treted controls (P = 0.25 nd P = 0.15) (Fig. 7). Yields nd weights of lepidopteron dmged hed (Iceberg) heds were not found significntly different mong tretments including the un-treted controls (P = 0.50 nd P = 0.56 respectively) (Fig.6). Plnt tissue nlysis ws done to determine potentil tretment effects on nitrogen (N) nd potssium (K) content. However, the lbortory compiled the smples bsed on tretment nd the bility to nlyze the dt vrition mong replictions in tretment ws lost. I hve ttched the nlysis reports s n ppendix to this document to be used s ncillry dt. Summry The lck of differences in tretments nd the untreted controls reflects the impct tht light insect pressure hs during the trnsition from the hottest prt of the yer to the coolest in the Plo Verde Vlley. Adult silverlef whiteflies popultions seemed to plteu between 11/10-11/18 nd were found only in low numbers cross ll tretments including the un-treted control. Relisticlly it is difficult to stte tht the tretments were unsuccessful since pest pressure ws reltively light for evlution of select insecticide formultions.

4 13.1 ft ft ft ft. Fig. 1. Aeril mp of 6 th Ave. University of Cliforni reserch plot. Broccoli Erly lettuce Iceberg 3 2 Buffer row Treted row Untreted row Buffers re 10 ft Control Untreted Control Plot (checks) 2 Shnk Corgen (5 fl. Oz/A) Spry Corgen 2 bnd over the top (5 fl. Oz./A) 4 Spry Movento (5 fl. Oz./A) every 7d Spry Rdint SC (5 fl. Oz./A) every 7d 6 Spry Synpse (3 Oz./A) every 7d Spry Avunt (3.5 fl. Oz./A ) every 7d Mx. (14 fl. Oz./A) Fig. 2. Plot mps of treted lettuce plots compred to un-treted controls with plot size of 39.3 ft3 (13.1 liner feet x 3 ft./on center) in 2010.

5 Men no. whitefly dults/lef Men no. whitefly dults/lef 2.50 Fll lettuce whitefly chemicl efficcy tril on green ('Del Sol') Romin lettuce in the Plo Verde vlley Untreted Corgen (5 fl. Oz/A) Corgen 2 bnd over the top (5 fl. Oz./A) Movento (5 fl. Oz./A) Rdint SC (5 fl. Oz./A) Synpse (3 Oz./A) Avunt (3.5 fl. Oz./A ) Smple dte Fig. 3. Men cumultive weekly whitefly counts on treted Romin lettuce plots compred to un-treted control in Fll lettuce whitefly chemicl efficcy tril on hed ('1221') lettuce in the Plo Verde vlley Untreted Corgen (5 fl. Oz/A) Corgen 2 bnd over the top (5 fl. Oz./A) Movento (5 fl. Oz./A) Rdint SC (5 fl. Oz./A) Synpse (3 Oz./A) Smple dte Fig 4. Men cumultive weekly whitefly counts on treted Iceberg lettuce plots compred to untreted control in 2010

6 Fll Hed (cv. '1221') Lettuce Eend-of-seson Yield nd Weights for Individul Tretments Count Weight (Kg) Tretments Fig. 5. End-of-seson hed lettuce yield dt showing tretment yields nd weights (Kg) evluted in the Plo Verde Vlley Fll Hed (cv. '1221') Lettuce End-of-seson Lepidopter Dmge Yield nd Weights for Individul Tretments Count Weight (Kg) Tretments Fig. 6. End-of-seson hed lettuce yield dt showing lepidopteron dmged heds nd weights (Kg) by tretment evluted in the Plo Verde Vlley

7 35 Erly (cv. 'Del Sol') Lettuce End-of-seson Yield nd Weights for Individul Tretments Count Weight (Kg) Tretments Fig. 7. End of seson erly lettuce yield dt showing tretment yields nd weights (Kg) evluted in the Plo Verde Vlley 3 3 Erly (cv. 'Del Sol') Lettuce End-of-seson Lepidopter Dmge Yield nd Weights for Individul Tretments Count Weight (Kg) Tretments Fig. 8. End-of-seson erly lettuce yield dt showing lepidopteron dmged heds nd weights (Kg) by tretment evluted in the Plo Verde Vlley

8 Tble 1. Whitefly insect counts, lettuce(s) yield, weights, lepidopteron dmged lettuce yields nd weights. Blythe CA Men whitefly counts ± SE Men yields (counts) nd weights (Kg) ± SE Cultivr n # Whitefly n # Totl yield Totl weight # Lepidopter dmged Lepidopter Dmged weight Del Sol 1 Untreted control ± ± ± ± ± Corgen (5 fl. Oz./A) ± ± ± ± ± Corgen 2 (5 fl. Oz./A) ± ± ± ± ± Movento (5 fl. Oz./) ± ± ± ± ± Rdint SC (5 fl. Oz./A) ± ± ± ± ± Synpse (3 Oz./A) ± ± ± ± ± Avunt (3.5 fl. Oz./A) ± ± ± ± ± 0.17 Experimentl Untreted control ± ± ± ± ± Corgen (5 fl. Oz./A) ± ± ± ± ± Corgen 2 (5 fl. Oz./A) ± ± ± ± ± Movento (5 fl. Oz./) ± ± ± ± ± Rdint SC (5 fl. Oz./A) ± ± ± ± ± Synpse (3 Oz./A) ± ± ± ± ± Avunt (3.5 fl. Oz./A) ± ± ± ± ± 0.17

9 Appendix Pictures of erly (cv. Del sol ) lettuce in experimentl plots just prior to field evlution hrvest Pictures of hed (cv ) lettuce in experimentl plots just prior to field evlution hrvest