Evaluation of Selected Insecticides for Control of Insect Pests of Soybeans. Beaumont, TX

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Clementine Bridges
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1 Title: Evlution of Selected Insecticides for Control of Insect Pests of Soyens. Beumont, TX Project Investigtor: M.O. Wy Texs A&M University Agriculturl Reserch & Extension Center 1509 Aggie Drive Beumont, TX (409) (phone) (409) (fx) (e-mil) Introduction Novel insecticides should e continully evluted for ctivity ginst insect pests of soyens. Efficcy dt provide crucil informtion to ssist in the registrtion of new pest mngement tools for Texs soyen frmers. The purpose of this experiment ws to evlute novel nd stndrd insecticides for ctivity ginst the rry of insects ttcking soyens grown on the Upper Gulf Cost of Texs. Mterils nd Methods The experiment ws conducted t the TAMU Agriculturl Reserch nd Extension Center t Beumont in 2001 nd ws designed s rndomized complete lock with 12 tretments nd four replictions. Plot size ws 8 rows (30 inches etween rows) x 90 ft. On 18 My, Hrtz 7550 RR soyens were plnted into Levc soil followed y ppliction of Squdron t 3 pt/cre. Plots were not irrigted ut were rinfed throughout the experiment. Soyens emerged to good stnd on 24 My. Weeds were controlled y timely cultivtion. Soyens were inspected for stge of growth t pproximtely weekly intervls from emergence to mturity. On 4 Sep (when soyens were R4/5), Lepidopter were oserved eginning to increse in plots. On this dte, plots were smpled for insects y tking 20 sweeps per plot with 15 inch dim sweep net. This ws the pre-tretment smple. Contents of the net were plced in plstic g which ws frozen. At lter dte, contents of gs were thwed nd inspected for rthropods (identified nd counted). On 6 Sep, tretments were pplied with two-person spry rig (13 nozzles, tip size, 50 mesh screens, 21.7 ft spry swth, finl spry volume 12.3 gp) pressurized with CO 2 t psi. Ltron CS-7 t 0.125% v/v ws dded to the Intrepid tretments. Plots were smpled s previously descried on the following dtes: 7 Sep, 10 Sep, 14 Sep, 25 Sep, 2 Oct nd 18 Oct. On 22 Oct, 30 leflets (10 from ottom, middle nd top 1/3 of cnopy) were collected from ech plot. Leflets were frozen nd thwed lter for determintion of % defolition (sed on defolition templtes). On 26 Nov, plots were hrvested (two, 90 ft rows in the center of ech plot) with smll plot comine. Yields were djusted to 13% moisture. Smples of seed were collected from ech plot nd rted for qulity. 127

2 Results Lepidopter: Popultions of soyen looper (Pseudoplusi includens) nd green cloverworm (Plthypen scr) were too low for tretment evlution; however, ll tretments significntly reduced velveten cterpillr (Anticrsi gemmtlis) 1 nd 7 dys fter ppliction (Tles 1-3). A second infesttion of velveten cterpillr ppered out 3 weeks fter tretment ppliction. This ws n unusul occurrence. At 26 dys fter ppliction, Asn; Krte; ll rtes of Stewrd nd Intrepid; nd the low rte of Trcer tretments significntly reduced velveten cterpillr popultions. Best residul control ws chieved y the Krte, Asn, Stewrd, nd high rte of Intrepid tretments. Penttomide: For the most prt, phytophgous stink ug [primrily southern green stink ug (Nezr viridul) nd rown stink ug (Euschistus spp.)] popultions were too low for meningful evlution; however, 26 dys fter ppliction, the Krte tretment gve the est control (Tle 7). Memrcide: Threecornered lflf hopper (Spissistilus festinus) nymphl popultions were low during the experiment ut dult densities were high (Tles 8 nd 9). The only tretments tht controlled threecornered lflf hopper were Krte nd Asn. At 4 dys fter ppliction, the Asn nd Krte tretments provided etter thn 90% control. Miscellneous: Popultions of ll other rthropods were too low for meningful evlutions, lthough the mid nd high rtes of Stewrd tretments my hve prtilly controlled grsshoppers (Tles 11-15). Yield: Yields rnged from 27.6 to 34.2 u/cre, ut tretment differences were not significnt (Tle 18). Seed Qulity: Seed qulity ws, in generl, reltively good (Tle 19). Best seed qulity ws produced in the Krte tretment. Defolition: Defolition ws highest in the untreted ut ll insecticide tretments exhiited over 20% defolition which suggests tht tretment pplictions were pplied lte (Tle 19). Erlier pplictions my hve reduced defolition in selected tretments. 128

3 Tle 1. Soyen insecticide evlutions (soyen looper), Beumont, TX, no. soyen looper/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer Trcer Lrvin Intrepid 2F Intrepid 2F Intrepid 2F Stewrd SC Stewrd SC Stewrd SC Asn XL Krte Z Untreted NS NS NS NS NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 129

4 Tle 2. Soyen insecticide evlutions (green cloverworm), Beumont, TX, no. green cloverworm/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer Trcer Lrvin Intrepid 2F Intrepid 2F Intrepid 2F Stewrd SC Stewrd SC Stewrd SC Asn XL Krte Z Untreted NS NS NS NS NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 130

5 Tle 3. Soyen insecticide evlutions (velveten cterpillr), Beumont, TX, no. velveten cterpillr/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer cd cd 2.0 Trcer c Lrvin cd c 3.0 Intrepid 2F c cd 3.3 Intrepid 2F c cd 0.8 Intrepid 2F de 1.3 Stewrd SC c cde 1.5 Stewrd SC de 1.5 Stewrd SC e 0 Asn XL d e 1.3 Krte Z d e 1.8 Untreted NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 131

6 Tle 4. Soyen insecticide evlutions (lepidoptern lrve), Beumont, TX, no. lepidoptern lrve/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer cd cd 2.8 Trcer c Lrvin cd c 4.8 Intrepid 2F c cd 4.3 Intrepid 2F cd 1.0 Intrepid 2F de 2.0 Stewrd SC c cde 1.8 Stewrd SC de 1.5 Stewrd SC e 0.3 Asn XL d e 3.0 Krte Z cd e 3.5 Untreted NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 132

7 Tle 5. Soyen insecticide evlutions (phytophgous stink ug nymphs), Beumont, TX, no. phytophgous stink ug nymphs/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer c Trcer d Lrvin cd Intrepid 2F cd Intrepid 2F Intrepid 2F cd Stewrd SC cd Stewrd SC d Stewrd SC d Asn XL c Krte Z d Untreted NS NS NS NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 133

8 Tle 6. Soyen insecticide evlutions (southern green stink ug dults), Beumont, TX, no. southern green stink ug dults/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer Trcer Lrvin Intrepid 2F Intrepid 2F Intrepid 2F Stewrd SC Stewrd SC Stewrd SC Asn XL Krte Z Untreted NS NS NS NS NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 134

9 Tle 7. Soyen insecticide evlutions (rown stink ug dults), Beumont, TX, no. rown stink ug dults/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer Trcer Lrvin Intrepid 2F Intrepid 2F Intrepid 2F Stewrd SC Stewrd SC Stewrd SC Asn XL Krte Z Untreted NS NS NS NS NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 135

10 Tle 8. Soyen insecticide evlutions (phytophgous stink ug nymphs + dults), Beumont, TX, no. phytophgous stink ug nymphs + dults/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer Trcer Lrvin Intrepid 2F c 4.3 Intrepid 2F c 7.8 Intrepid 2F c 5.3 Stewrd SC c 3.5 Stewrd SC c 5.3 Stewrd SC c 3.3 Asn XL c 5.8 Krte Z c 2.5 Untreted NS NS NS NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 136

11 Tle 9. Soyen insecticide evlutions (threecornered lflf hopper nymphs), Beumont, TX, no. threecornered lflf hopper nymph/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer Trcer Lrvin Intrepid 2F Intrepid 2F Intrepid 2F Stewrd SC Stewrd SC Stewrd SC Asn XL Krte Z Untreted NS NS NS NS NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 137

12 Tle 10. Soyen insecticide evlutions (threecornered lflf hopper dults), Beumont, TX, no. threecornered lflf hopper dults/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer c Trcer e Lrvin de Intrepid 2F cde Intrepid 2F Intrepid 2F cd Stewrd SC c cd Stewrd SC cde Stewrd SC Asn XL cd 4.0 c 4.8 c 7.5 e Krte Z d 3.0 c 5.8 c 15.3 cde Untreted cde NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 138

13 Tle 11. Soyen insecticide evlutions (threecornered lflf hopper nymphs + dults), Beumont, TX, no. threecornered lflf hopper nymphs + dults/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer c Trcer e Lrvin de Intrepid 2F cde Intrepid 2F Intrepid 2F cd Stewrd SC c cd Stewrd SC cde Stewrd SC Asn XL c 4.0 c e Krte Z c 3.3 c cde Untreted cde NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 139

14 Tle 12. Soyen insecticide evlutions (orthoptern nymphs + dults), Beumont, TX, no. orthoptern nymphs + dults/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer c 2.8 cd Trcer c 1.3 cd Lrvin c 2.5 cd c Intrepid 2F Intrepid 2F Intrepid 2F c c Stewrd SC c 1.5 cd c Stewrd SC c 0.5 d c Stewrd SC c 1.0 d c Asn XL c 1.8 cd c Krte Z c c Untreted c 3.5 c c NS NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 140

15 Tle 13. Soyen insecticide evlutions (nded cucumer eetle), Beumont, TX, no. nded cucumer eetle/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer Trcer Lrvin Intrepid 2F Intrepid 2F Intrepid 2F Stewrd SC Stewrd SC Stewrd SC Asn XL Krte Z Untreted NS NS NS NS NS NS Mens in column followed y the sme or no letter re not significntly different t 0the 5% level (ANOVA nd DMRT). Before ppliction 141

16 Tle 14. Soyen insecticide evlutions (lefhoppers), Beumont, TX, no. lefhoppers/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer c 0.3 c Trcer d 0 c Lrvin cd 0 c Intrepid 2F d Intrepid 2F c Intrepid 2F cd 0 c Stewrd SC cd 0.5 c Stewrd SC c Stewrd SC cd 0 c Asn XL d 0.3 c Krte Z cd 0 c Untreted cd NS NS NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 142

17 Tle 15. Soyen insecticide evlutions (mush ugs), Beumont, TX, no. mush ugs/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer Trcer Lrvin Intrepid 2F Intrepid 2F Intrepid 2F Stewrd SC Stewrd SC Stewrd SC Asn XL Krte Z Untreted NS NS NS NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 143

18 Tle 16. Soyen insecticide evlutions (spiders), Beumont, TX, no. spiders/20 sweeps Dys fter ppliction Tretment [l(ai)/c] B Trcer Trcer Lrvin Intrepid 2F Intrepid 2F Intrepid 2F Stewrd SC Stewrd SC Stewrd SC Asn XL Krte Z Untreted NS NS NS NS NS NS NS Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). Before ppliction 144

19 Tle 17. Soyen insecticide evlutions (yield), Beumont, TX, 2001 Yield (u/a) djusted to 13% moisture Tretment [l(ai)/c] I II III IV 0 Trcer Trcer Lrvin Intrepid 2F Intrepid 2F Intrepid 2F Stewrd SC Stewrd SC Stewrd SC Asn XL Krte Z Untreted Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). NS 145

20 Tle 18. Soyen insecticide evlutions (seed qulity), Beumont, TX, 2001 Seed qulity (1-5) Tretment [l(ai)/c] I II III IV 0 Trcer Trcer c Lrvin c Intrepid 2F Intrepid 2F c Intrepid 2F c Stewrd SC c Stewrd SC Stewrd SC Asn XL c Krte Z c Untreted c Seed qulity (1-5): 1 = excellent, 5 = very poor Mens in column followed y the sme or no letter re not significntly different t the 5% level (ANOVA nd DMRT). 146

21 Tle 19. Soyen insecticide evlutions (defolition), Beumont, TX, 2001 Defolition (%) Tretment [l(ai)/c] I II III IV 0 Trcer Trcer Lrvin Intrepid 2F Intrepid 2F Intrepid 2F Stewrd SC Stewrd SC Stewrd SC Asn XL Krte Z Untreted Mens in column followed y the sme or no letter re not significntly different t the 11% level (ANOVA nd DMRT). 147

Project Title: Developing Stink Bug Thresholds for Late Maturity Group Soybeans on the Upper Gulf Coast. Beaumont, TX

Project Title: Developing Stink Bug Thresholds for Late Maturity Group Soybeans on the Upper Gulf Coast. Beaumont, TX. 2001. Principal Investigator: M.O. Way Associate Professor, Entomology Texas Agricultural