| Sumario: | Abstract
BACKGROUND:SpinosadisrecommendedforcontrolofSpodopterafrugiperda(J.E.Smith)larvae;itsapplicationwithphagostimulants may reduce the quantity of active ingredient required for effective pest control. Spinosad (Tracer®) was formulated inmaizeflourmatrixgranulesandthreefieldtestscompared10–100ppma.i.granules(equivalentto0.24–2.4ga.i.ha–1)with Tracerasanaqueousspray(200ppma.i.;60ga.i.ha–1),andtherecommendedapplicationratesofBacillusthuringiensis,achemicalandanuntreatedcontrolswereperformed.
RESULTS:The100ppmspinosadgranulesresultedinsimilarS.frugiperdamortalitycomparedwiththechemicaltreatmentsin allthreefieldtrials,andresultedinasignificantlyhighermaizegrainyieldcomparedwithunformulatedandcontroltreatments (4141vs.2857and2407kgha–1,respectively)thatwassimilartothechemicaltreatment(3778kgha–1).Bioassaysofgranules stored at room and cold temperatures showed that after 5years, ∼ 70% of the original activity remained (OAR) of spinosad whenformulatedasgranules.Nevertheless,after9years,efficacywasreduced(26.2%and48.5%OAR)atbothroom(25∘C)and refrigeratedtemperatures(4∘C).
CONCLUSION:Spinosad,inthegranularphagostimulantformulationsevaluatedinthisstudy,hadadvantagesmeasuredashigh efficacyandlongshelflife.
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