2010 Buyer s Guide for Bt Corn in Alabama

Transcription

1 2010 Buyer s Guide for Bt in Albm Kthy Flnders, Extension Entomologist nd Associte Professor; Brend Ortiz, Extension Agronomist nd Assistnt Professor; nd Austin Hgn, Extension Plnt Pthologist nd Professor, Auburn University Februry 5, 2010 Bt corn* is relly form of crop insurnce tht comes in the seed bg. The presence of one or more Bt genes in corn hybrid will not increse yield potentil. Insted, the gene(s) prevent yield losses from certin insects. Therefore, the most importnt thing to remember is tht if the insect popultion in your field is high enough, the Bt corn will py off. If the insect pressure is not there, then you won t get your money bck. So it is mtter of deciding if the risk is high enough to wrrnt the insurnce. This informtion sheets discusses situtions in which Bt corn cn py off. There re different kinds of Bt corn. Some of the Bt genes protect ginst stlk borers. Some protect the roots from western corn rootworm. Still others help prevent lef nd er dmge from vrious cterpillrs including corn erworm nd fll rmyworm. These genes re bundled together in vrious combintions, with or without herbicide tolernce genes. See Tbles 1-2 below for detils regrding trnsgenic products tht include Bt insect resistnce. Mke sure tht the seed deler explins exctly wht kind of Bt corn hybrids he is selling. How much does Bt technology cost? It is importnt to work with your seed deler to understnd how much you re pying for the Bt technology, then weigh tht ginst the expected benefits. The price of corn seed hs risen drmticlly in the pst decde. This is becuse the price includes insecticide nd fungicide seed tretments, s well s herbicide tolernce nd Bt trits. The cost of Bt technology tht protects ginst corn borers nd other cterpillrs is bout $3.70 for older products such s YieldGrd Borer, Agrisure CB/LL, nd Herculex I. The cost of the Bt technology for western corn rootworms is lso bout $3.70 per cre. This yer mny corn hybrids include suite of trnsgenes mrketed under the product nme Genuity VT Triple Pro (GENVT3P). This product contins genes for Roundup tolernce, s well s for cterpillr nd western corn rootworm control. The insect protection prt of GENVT3P costs bout $10.50 per cre.** Alwys pick hybrids with good good gronomic fit for your frm, nd mke sure the hybrid hs good disese resistnce. Alwys consider the yield potentil of the hybrid fmily involved, nd mke sure the hybrid is dpted for plnting in the Southest. Then think bout wht other vlue-dded trits re vilble, such s herbicide resistnce or Bt corn technology. * tht contins insect resistnce genes from the bcterium Bcillus thuringiensis ** bsed on compring the cost of hybrid with GENVT3P with the sme hybrid sold with Roundup resistnce lone.

2 To help preserve the usefulness of Bt corn, the Environmentl Protection Agency requires tht non-bt corn be plnted on prt of the corn cres on ech frm s refuge. See Tbles 1-2 below for detils bout the mount of refuge corn needed for ech type of Bt corn. Most Bt corn for boveground cterpillrs hs 50% refuge requirement. However, hybrids contining Genuity VT Triple Pro hve just 20% refuge requirement. This difference in the refuge requirement will ffect the economic returns relized from prticulr Bt technology. There re four situtions where it is esy to recommend plnting Bt corn hybrids (see Tble 1 for listing of Bt corn products recommended for ech of these situtions). The resoning for these recommendtions is described below for ech of these situtions. Sitution 1. Northwest Albm, with consistently high Southwestern corn borer popultions Sitution 2. tht will be plnted fter the recommended plnting dte Sitution 3. plnted in the southern tier of counties where pressure from fll rmyworm is the highest Sitution 4. Non-rotted (corn fter corn) in north Albm, where western corn rootworm cn be problem The fifth sitution in the tble is corn plnted t the recommended plnting dte, in which the corn erworm is the primry insect contributing to yield loss, yer in nd yer out. Genuity VT Triple Pro (GENVT3P) my py off in this sitution. See below for the resoning involved. Tble 1. Bt corn technology worksheet showing which Bt corn products re pproprite for different situtions. For every cre Sitution* with this tech- Product Trde Nme 1 stlk 2 lte 3 South 4 rootworworm 5 er- nology plnt this mny non-bt (Abbrevition)** borers plnting AL cres s refuge Genuity VT Triple PRO (GEN yes yes yes yes yes 0.25 cre VT3P) YieldGrd Borer (YGCB) yes yes mybe no no 1 cre or Agrisure CB/LL Herculex I (BT (HX I)) yes yes yes no no 1 cre Herculex XTRA (CRW yes yes yes yes no 1 cre (HXRW) + BT (HX 1)) YieldGrd VT Triple (VT3) or yes yes mybe yes no 1 cre YieldGrd Plus (YGPL) Agrisure CB/LL/RW or yes yes mybe yes no 1 cre Agrisure 3000 GT Herculex RW (CRW (HXRW)), Agrisure RW, or YieldGrd Rootworm (YGRW) no no no yes no.25 cre *See below for detiled discussion of ech of these situtions **The most commonly vilble commercil products re listed. Others re vilble, see Tble 2 below for complete listing including products tht my be vilble for Southern dpted hybrids in 2011).

3 Remember, Bt corn is insurnce, there re no gurntees tht insect pressure will be high enough in every field every yer. A good exmple of this is dt from Austin Hgn s 2009 trils in Brewton nd Firhope, using hybrids contining Herculex I, YieldGrd Borer, or YieldGrd VT Triple. A significnt difference in yield ws observed in Brewton, but not in Firhope (LSD P0.05): Yield (Bushels per Acre) b Bt trit Non-Bt 80 Brewton Firhope Situtions where Bt Technology is Most Likely to Py Off Sitution 1. Do you hve grow corn in n re known to hve consistent stlk borer problems? If so, pick hybrid tht works for Sitution 1 in Tble 1. Advntge for Bt corn for SW corn borer: 9 bushels per cre in 2004 University of Georgi Archive Bugwood.org Southwestern corn borer distribution R. Duffield, AL Whet & Feed Grin Study

4 Sitution 2. Do you think you will hve to plnt fter the recommended plnting dte for your re? If so, pick trit suited for Sitution 2 in Tble 1. The lter you plnt, the greter the risk from cterpillr pests such s fll rmyworm nd corn erworm. Plnting dte studies in , using YieldGrd Borer (YGCB) or Agrisure CB/LL technology, showed tht the lter you plnt, the more likely it ws tht Bt hybrids would yield more thn conventionl hybrids. Newer technologies, such s Herculex I or Genuity VT Triple Pro, will show even more mrked plnting dte effects. Note: lte plnting lso brings risks of poor pollintion, lower yield potentil, nd disese outbreks. Bt hybrids yielding t lest 10% more thn the best stndrd, 1998 No. Bt hybrids yielding 10% Loction more/no. Bt hybrids Plnting Dte norml mid lte Hedlnd 1/4 3/4 4/4 Firhope 2/4 3/4 4/4 Tllssee 0/4 0/4 4/4 Mrion Jct 0/3 0/3 3/3 Crossville 0/3 0/3 3/3 *mid = usully My, lte = usully in June Bt hybrids yielding t lest 10% more thn the best stndrd, 1999 No. Bt hybrids yielding 10% Loction more/no. Bt hybrids Plnting Dte norml mid lte Hedlnd - 1/2 - Firhope 0/3 5/5 5/5 * mid = usully My, lte = usully in June Sitution 3. Do you live in the southern tier of counties which hve the gretest likelihood of dmge from fll rmyworm even t the recommended plnting dte? If so, pick trit for Sitution 3 in Tble 1. This recommendtion is bsed on plnting dte studies conducted in with YieldGrd Borer (YGCB) or Agrisure CB/LL technology (see tble in Sitution 2, bove). Pressure from fll rmyworm ws high enough to recommend plnting YGCB in these res, even though this technology ws only modertely effective ginst the pest. Since then, newer Bt technologies hve become vilble tht re even more effective ginst fll rmyworm (e.g., Herculex I nd Genuity VT Triple Pro).

5 Sitution 4. Do you grow corn fter corn in n re known to hve problems with western corn rootworm? If so, pick hybrid tht works for Sitution 4 in Tble 1. Roots dmged by lrve western corn rootworm dult, bout 1/4" long. Western corn rootworm s of 2009 found in trps re t gretest risk not found in trps A Sitution Where Bt My Py Off Sitution 5. which is perhps the most common sitution in Albm, is corn plnted t the recommended plnting dte, in which the primry insect contributing to yield loss, yer in nd yer out, is the corn erworm. Fll rmyworm dmge vries from yer to yer in this sitution but cn be significnt. One trnsgenic product, Genuity VT Triple Pro (GENVT3P), is highly effective ginst these two pests. In 2011, two more products will be vilble for this sitution (Genuity SmrtStx nd Agrisure Vipter). The yield return from this technology will depend primrily on how high the pressure is from corn erworm nd fll rmyworm. Field trils in the Southest, from industry nd university reserchers, hve shown n verge 3 bushel per cre yield difference between hybrid with GENVT3P nd its corresponding isoline (in res where corn erworm nd fll rmyworm were the primry pests). The following 2009 dt, courtesy Dr. Dvid Buntin, University of Georgi, shows how the GENVT3P product hs significntly less er dmge thn YGCB or non-bt corn. Infested Plnts Non Bt YGCB GENVT3P % Infested plnts b c Griffin PD2 Tifton PD3 Plins PD2 Studies re ongoing to determine if this greter er protection will result in consistently lower fltoxin levels. To dte, results regrding fltoxin hve been mixed. This my be due to the fct tht other insects, including stink bugs, nd mize weevils, hve lso been ssocited with higher fltoxin contmintion. b c c

6 Tble 2. Reltive Efficcy of Vrious Bt Products 1 Product Trde Nme (Abbrevition) Erworm (er) Fll Armyworm (whorl) Borers 2 (stlk) Western Rootworm 3 (roots) Bt for Controlling Above-Ground Cterpillrs (Moths, Lepidopter) Herculex I (BT (HX 1)) Cutworm (seedling) Lesser stlk Borer 4 6 Poor-Fir Excellent Excellent None Good Good- Excellent Refuge Requirement 5 Originl Trget Pests (Bt Protein) Event(s) 50% borer, western ben cutworm, blck cutworm nd fll rmyworm resistnce (Cry1F) Liberty (glufosinte) herbicide tolernce Agrisure CB/LL Fir-Good Good Excellent None Poor Poor-Fir 50% borer protection (Cry1Ab) Liberty (glufosinte) herbicide tolernce YieldGrd Borer (YGCB) YieldGrd VT Pro (VTP) TC1507 Fir-Good Good Excellent None Poor Poor-Fir 50% borer protection (Cry1Ab) MON810 Very Good Excellent Excellent None Poor Poor-Fir 20% borer, fll rmyworm, corn erworm protection (Cry1A.105 nd Cry2Ab) Bt for Controlling Below-Ground Rootworms (Beetles, Coleopter) Agrisure RW None None None Fir-Good None None 20% rootworm protection (modified Cry3A) Herculex RW CRW (HXRW) YieldGrd Rootworm (YGRW) YieldGrd VT Rootworm/RR2 (VTRR2) None None None Excellent None None 20% rootworm resistnce (Cry34/35Ab1) Liberty (glufosinte herbicide tolernce) MON89034 DAS None None None Good None None 20% rootworm protection (Cry 3Bb) MON863 None None None Excellent None None 20% rootworm protection (Cry3Bb) Roundup (glyphoste) herbicide tolernce Bt for Controlling Above-Ground Cterpillrs (Lepidopter) nd Below-Ground Rootworms (Coleopter) YieldGrd Plus (YGPL) Fir-Good Good Excellent Good Poor Poor-Fir 50% borer protection (Cry1Ab) rootworm protection (Cry3Bb) MON810 MON863 YieldGrd VT Triple (VT3) Fir-Good Good Excellent Excellent Poor Poor-Fir 50% borer protection (Cry1Ab) rootworm protection (Cry3Bb) Roundup (glyphoste) herbicide tolernce MON 810 Agrisure CB/LL/RW Fir-Good Good Excellent Fir-Good Poor Poor-Fir 50% borer protection (Cry1Ab) rootworm protection (modified Cry3A) Liberty (glufosinte) herbicide tolernce continued

7 Tble 2. Reltive Efficcy of Vrious Bt Products 1 Product Trde Nme (Abbrevition) Erworm (er) Fll Armyworm (whorl) Borers 2 (stlk) Western Rootworm 3 (roots) Cutworm (seedling) Lesser stlk Borer 4 Bt for Controlling Above-Ground Cterpillrs (Lepidopter) nd Below-Ground Rootworms (Coleopter) Refuge Requirement 5 Originl Trget Pests (Bt Protein) Event(s) Agrisure 3000 GT 6 Fir-Good Good Excellent Fir-Good Poor Poor-Fir 50% borer protection (Cry1Ab) rootworm protection (modified Cry3A) Roundup (glyphoste) herbicide tolernce Liberty (glufosinte) herbicide tolernce Herculex XTRA (CRW (HXRW) + BT (HX 1)) Poor-Fir Excellent Excellent Excellent Good Good- Excellent 50% borer, fll rmyworm, western ben cutworm, blck cutworm nd resistnce (Cry1F) rootworm resistnce (Cry34/35Ab1) Liberty (glufosinte) herbicide tolernce SYTGA21 TC1507 DAS Genuity VT Triple PRO (GENVT3P) Genuity SmrtStx (VT3P/HXX) Agrisure Vipter 7 stcked with Agrisure 3000 GT or Agrisure CB/LL/RW or Agrisure CB/LL Very Good Excellent Excellent Excellent Poor Poor-Fir 20% borer, fll rmyworm, corn erworm protection (Cry1A.105 nd Cry2Ab) rootworm protection (Cry3Bb) Roundup (glyphoste) herbicide tolernce Very Good Excellent Excellent Excellent Good Good- Excellent Excellent Excellent Excellent Fir- Good if stcked with the RW trit (MIR 604) 20% borer, fll rmyworm, corn erworm, western ben cutworm, blck cutworm protection (Cry1A.105, Cry2Ab, Cry1F) rootworm protection (Cry3Bb, Cry34/35Ab1) Roundup (glyphoste) herbicide tolernce Liberty (glufosinte) herbicide tolernce Very Good? 20% erworm, western ben cutworm, blck cutworm, nd fll rmyworm control (Vip3A) borer protection (Cry1Ab) Liberty (glufosinte) herbicide tolernce depending on stck: Roundup (glyphoste) herbicide tolernce nd corn rootworm protection (modified Cry3A) MON MON TC1507 DAS MIR162 depending on stck: SYTGA21 1 Most of these insect resistnt products re mrketed s stcks with herbicide resistnt products. 2 Southwestern corn borer, Europen corn borer, nd sugrcne borer. 3 There re severl species of corn rootworm in the Southest. Southern corn rootworm is the most prevlent species. These rootworm products re not effective ginst southern corn rootworm. They re effective ginst western corn rootworm lrve, which occur in res such s north Albm nd north Georgi. 4 Lepidoptern Bt trits do not specificlly list lesser cornstlk borer s trget pest. 5 See product Insect Resistnce Mngement (IRM) documenttion from the seed compnies for more detils. 6 The exct mening of these terms is somewht rbitrry. Excellent mens better thn 95 percent control. Poor mens bout 30 to 50 percent control. Rnkings re ment to be reltive, not bsolute. 7 When this document ws printed, Vipter ws not for sle in the U.S. This product will not be vilble until ll necessry regultory pprovls nd uthoriztions hve been grnted.