Soybean Fungicide and Insecticide Seed Treatments (2006 Final Report)

Transcription

1 Soyen Fungicide nd Iecticide Seed Tretments (2006 Finl Report) Purpose: The ojective of this study ws to investigte new iecticide seed tretments for soye. Cruiser ws registered recently nd Gucho hs yet to e registered in Cnd. Widespred infesttio of soyen phids cross Ontrio in 2001 nd 2003 drsticlly reduced yields. Although folir iecticides cn effectively control this pest, new mngement optio such s seed tretments could id in their control. Other iect pests re lso on the rise in Ontrio. The spring of 2006 sw very high overwintering en lef eetle popultio in the province. Fields reched threshold levels s fr north s Huron County for the first time in Little reserch hs een reported on the ctivity of new iecticide seed tretments on phids, en lef eetles nd other iect pests cross multiple field loctio. In ddition to the iecticides tested, fungicide seed tretment ws lso included in the tretments. The use of fungicide seed tretment on corn nd whet re stndrd prctice. But, the mjority of soye plnted in Ontrio do not receive fungicide seed tretment. Since soye tend to e plnted lter thn corn, soil conditio re generlly more fvourle for rpid germintion nd emergence. However, when conditio re wet nd cool, soil orne diseses cuse coiderle seed nd seedling dmge. The extent of the dmge these diseses will cuse depends on moisture, temperture, overll plnt helth nd soil type. Cold wet soils, crusting, hevy ri, compction nd even post-emergent hericides cn ll cuse plnt stresses, which mke the seedlings more susceptile to diseses. This project ws initiled in 2004 y the University of Guelph, Ridgetown College nd Ontrio Ministry of Agriculture, Food nd Rurl Affirs to evlute the efficcy of soyen seed tretments on new nd expnding pests such s phids, en lef eetles, pythium root rot etc. Methods: Experiments were estlished on more thn 30 fields cross southern Ontrio from 2004 to Multiple loctio cross wide geogrphicl re were necessry to increse the potentil for fields with vried iect nd disese levels. Tretments were rrnged in strip plot design, 10 feet wide y 410 feet long with 3 replictio per tretment. Check plots were monitored twice week from soyen emergence to the V2 stge for the presence of root disese nd soil pest iects such s Europen chfer, wireworm, nd seed corn mggot. Plnt popultio were determined in ll seed tretment strips pproximtely 21 dys fter emergence. Vigour rtings were determined sujectively on scle of 0-100%. The plots were monitored once--week from lte-june until mid- August for dditionl iect pests such s en lef eetle, potto lefhoppers, nd soyen phids. When phids were detected in the plots, counts were recorded. Seed yield nd hrvest moisture were tken. TREATMENTS INCLUDED: 1- UNTREATED CHECK (no fungicide or iecticide seed tretment) 2- MAXIM APRON

2 3- MAXIM APRON + 50 g per 100 kg of seed 4- MAXIM APRON g per 100 kg of seed Ben Lef Beetle Soyen Aphids Results nd Summry: Plnt stnd counts were tken pproximtely 21 dys fter seeding. Averged cross ll sites plnt stnd counts were higher y pproximtely 5000 plnts/cre for the Mxim Apron, plnts/cre for the Mxim Apron + Cruiser nd for the Mxim Apron + Gucho compred to the untreted check. See grph #1.

3 Grph #1: Seed Tretment Effects on Soyen Plnt Stnd 2004 c c Stnd (x 1000) The fungicide seed tretment showed numericlly greter plnt stnd count t 20 out of the 30 sites, ut ws only sttisticlly significnt t 5 of them (p < 0.10). Visul vigour rtings mirrored plnt stnd counts nd were significnt t 5 out of the 30 sites.(dt not shown) Iecticide seed tretments stnd counts were numericlly higher t 23 of the 30 sites, ut only 5 of these were sttisticlly significnt t the p=0.10 level. Averged cross ll the sites nd yers, modest ut significnt yield dvntges for oth the fungicide nd iecticide seed tretments re notle. See tle #1. Yields were numericlly higher for Mxim-Apron in 17 out of 30 trils compred to the untreted check, ut yields were sttisticlly significnt t only 3 out of the 30 sites. (p < 0.10). Mxim Apron plus n iecticide seed tretment yielded numericlly higher t 23 out of 30 sites nd 4 of these were sttisticlly significnt t p=0.10. See grph #2 for yield respoes.

4 Tle #1: Soyen Seed Tretment Yields ( ) Yield Advntge (u/c) (u/c) ** *** *** **, *** = sttisticlly significnt from untreted t p=0.01 nd p=0.001 Grph #2: Seed Tretment Effect on Soyen Yields Yield (u/c) The mgnitude of soyen respoe to seed tretments depended minly on the presence of root rot diseses, iect pressure, soil type nd wether. Mxim-Apron incresed plnt stnds y pproximtely 5000 plnts/cre, nd yields y n verge of 1.3 u/c. The gretest yield respoe ws on cly nd cly lom soils. Fields tht

5 suffered from soil crusting fter plnting hd greter respoe thn those with little or no emergence prolems. At one site where crusting ws evident, Mxim-Apron incresed plnt stnds y 38%. At the sites with sttisticlly significnt yield respoe, rhizoctoni nd pythium root rot were the min diseses prolems. At two sites where pythium reduced plnt stnds, yields were incresed y n verge of 32% or 11 u/c. Mxim Apron + Cruiser incresed plnt stnds y plnts/cre nd incresed yields y 1.9 u/c. Mxim-Apron + Gucho incresed plnt stnds y plnts/cre nd incresed yields y 1.9 u/cre. Seed tretments contining iecticides significntly reduced erly popultio of en lef eetle when they were present (up to 60% reduction). Significnt phid popultio were only oserved during the 2005 growing seson in these trils. Iecticide seed tretments kept phid levels lower thn the untreted check for the first 60 dys fter plnting, ut they hd little ffect on phids fter tht point. Typiclly, soyen phid popultio hve not reched threshold levels in Ontrio until July or August. For this reson, iecticide seed tretments hve not een n effective control mesure for this pest. In this set of experiments, the fungicide Mxim-Apron incresed yields y up to 32% when high levels of root rot were present nd when fields suffered from crusting. This occurred in 3 out of 30 fields cross 3 yers in these trils. When conditio were excellent for emergence nd erly growth, no yield enefit ws relized. Likewise, the use of n iecticide ws only eneficil when erly seson en lef eetle or seed corn mggots were prolem. Iecticide seed tretments were not effective in controlling soyen phids eyond 60 dys fter plnting. Acknowledgements: This project ws conducted collortively mong the following reserchers: Dr. Art Schfsm, Ridgetown Cmpus University of Guelph, Ridgetown, Ontrio N0P 2C0, ; Fx: ; E-mil: schfs@ridgetownc.uoguelph.c Dr. Dve Hooker Ridgetown Cmpus University of Guelph, Ridgetown, Ontrio N0P 2C0, ; Fx: ; E-mil: dhooker@execulink.com Horst Bohner, OMAFRA, 581 Huron St., Strtford, ON N5A 5T ; Fx: ; E-mil: horst.ohner@omf.gov.on.c Trcey Bute, OMAFRA, Agronomy Building, Ridgetown College, Box 400, Ridgetown, ON N0P 2C0, ; Fx: ; E-mil: trcey.ute@omf.gov.on.c