Impact of Rice Harvest Cutting Height and Ratoon Cropping on Late Season and Overwintering Stem Borer Infestations

Transcription

1 Impct of Rice Hrvest Cutting Height nd Rtoon Cropping on Lte Seson nd Overwintering Stem Borer Infesttions Stem oring pests of rice in the Gulf Cost Region (Lepidopter: Crmide) Sugrcne orer Ditre scchrlis (F.) Mexicn rice orer Eoreum loftini (Dyr) J.M. Beuzelin, A. Mészáros,M.O. Wy, nd T.E. Regn LSU AgCenter, Den Lee Reserch Sttion Formerly LSU AgCenter, Deprtment of Entomology Texs A&M AgriLife, Reserch & Extension Center t Beumont LSU AgCenter, Deprtment of Entomology Wy et l., Rey-Jones et l. 7 J. Sichuk J. Sichuk Stem orer injury to rice (Oryz stiv L.) Lck of uniformity in grin development Stem orer mngement in rice Insecticides -Chlorntrniliprole seed tretments - Pyrethroid pplictions, no economic thresholds Cultivr resistnce -Commercil cultivrs re susceptile Biologicl control -Prsitoids re not efficient Whiteheds nd roken culms Wy B. Cstro, Non-crop hosts -Yer-round source of E. loftini popultions Wy et l., Rey-Jones et l. 7, Lv et l., Beuzelin et l. Rice stule is potentil source of stem orer popultions Rice stule mngement in the Gulf Cost region Hrvest cutting height - vs. cm stule A. Mészáros N. Hummel

2 Rice stule mngement in the Gulf Cost region Hrvest cutting height - vs. cm stule Production of rtoon crop -Second crop developing from the min crop stule Rice Stule Mngement Experiments Ojective: Determine the impct of hrvest cutting height nd rtoon crop on stem orer infesttions in rice stule from summer to spring N. Hummel Beuzelin et l.. Crop Prot. : 7-55 Rice stule mngement experiments Southest Texs, yers: 7-8 nd 8-9 Cultivr: Cocodrie Plot size:.9 m.7 m (9 rows, 8. m ) Rice stule mngement experiments Dt collection fter min crop hrvest (lte August) Two min crop hrvest heights: cm vs. cm (RBD: strips, plots/hrvest height/strip) Impct of rice min crop hrvest cutting height on post-hrvest stem orer infesttions (lte August) 7 8 Stem orer loction in rice culms fter min crop hrvest (lte August, -cm stule) 7 8 No. stem orers / m 5 cm cm * E. loftini D. scchrlis No. stem orers / m 8 9 * cm cm E. loftini D. scchrlis No. stem orers / m 5 5 Ner culm se Low High E. loftini D. scchrlis No. stem orers / m 8 Ner culm se Low High E. loftini D. scchrlis E. loftini: F = 7.; P =. D. scchrlis: F =.; P =.78 E. loftini: F = 9.; P <. D. scchrlis: F =.7; P =.97 E. loftini: F = 9.; P <. D. scchrlis: F =.8; P <. E. loftini: F = 9.; P <. D. scchrlis: F =.; P =.8 ANOVA: SAS, Proc Glimmix, Norml distriution ANOVA: SAS, Proc GLIMMIX Tukey s HSD, α =.5: rs with the sme letters re not different

3 Rice stule mngement experiments Two stule mngement regimes -Min crop only (left unmnged) -Rtoon crop (fertilized, flooded, not treted with insecticides, hrvested in Novemer) No. E. loftini / m E. loftini lte nd post-growing seson densities in rtoon nd non-rtoon stule (Octoer-Mrch) Non-rtoon Rtoon No. E. loftini / m 7 5 Non-rtoon Rtoon Octoer Jnury Mrch Octoer Jnury Mrch Dt collection in lte Octoer, mid-jnury, nd mid-mrch Rtoon: F =.8; P =. Dte: F =.; P <. Rtoon Dte: F = 7.; P <. ANOVA: SAS, Proc GLIMMIX, Norml distriution Rtoon: F =.; P <. Dte: F = 89.; P <. Rtoon Dte: F =.7; P <. D. scchrlis lte nd post-growing seson densities in rtoon nd non-rtoon stule (Octoer-Mrch) No. D. scchrlis / m Octoer Jnury Mrch Rtoon: F =.; P =.89 Dte: F = 8.; P <. Rtoon Dte: F =.; P =.99 Non-rtoon Rtoon No. D. scchrlis / m Non-rtoon Rtoon Octoer Jnury Mrch Rtoon: F =.; P =. Dte: F = 5.5; P =.5 Rtoon Dte: F =.; P =. Discussion Rice stule mngement Lowering rice hrvest cutting height hs the potentil to decrese E. loftini infesttions Compred to D. scchrlis lrve nd pupe, reltively more E. loftini immtures re locted ner the top of rice culms Rice stule, rtoon nd non-rtoon, hrors lte seson nd overwintering stem orer popultions ANOVA: SAS, Proc GLIMMIX, Norml distriution Conclusions E. loftini nd D. scchrlis mngement in Gulf Cost rice Under conditions conducive to stem orer infesttions, stule mngement etween fll nd spring my e justified E. loftini nd D. scchrlis re not interchngele pests -Loction in rice culms -Oviposition ehvior -Tunneling ehvior -Sesonl ctivity Species-specific IPM strtegy needed? Acknowledgements Technicl ssistnce -Dvid Blouin, Professor of Sttistics (LSU AgCenter) - Blke Wilson, WseemAkr, Reserch ssocites (LSU AgCenter) -Jck Vwter, Frm reserch services mnger (Texs A&M AgriLife) Funding -USDA CSREES Crops-At-Risk IPM progrm grnt 8-5- Legspi et l. 997, Rey-Jones et l. 7, Showler & Cstro, Beuzelin et l.

4 Impct of Rice Hrvest Cutting Height nd Rtoon Cropping on Lte Seson nd Overwintering Stem Borer Infesttions

5 Insecticidl Control of Sp Feeders, Cheneyville, LA st Stule, HoCP 9-5 Insect numers counted on rd or th lef down from the whorl Tretments pplied with CO - pressurized ckpck spryer clirted to deliver gp t psi on July, Insecticidl Control of Sp Feeders Tretment Rte / cre No. per lef* Pre-tretment DAT DAT WIC SA WIC SA WIC SA Untreted check c Trnsform WG (sulfoxflor).5 oz c Bythroid XL (β-cyfluthrin). fl oz Besiege (chlorntrniliprole 9. fl oz γ-cyhlothrin) Admire Pro (imidcloprid). fl oz c Leverge (β-cyfluthrin + imidcloprid). fl oz c *Mens within columns followed y the sme letter re not different (P >.5, Tukey s test)