Brown Spot

Overview

Brown Spot, also known as Septoria leaf spot, is a foliar disease caused by Septoria glycines that primarily targets the lower canopy of soybeans.

The disease primarily targets the plant's principal photosynthetic organ. Brown Spot can also disrupt the physiological processes of the soybean plant. For example, the disease can hinder the plant's ability to absorb nutrients and water, impacting its overall health and productivity.

Additionally, defoliation triggered by Brown Spot can leave the pods exposed, increasing their vulnerability to other diseases and pests.

Brown Spot is not known to cause substantial yield losses. However, the actual impact on yield can fluctuate based on the timing of infection, disease severity, and the management strategies employed.

(Image Credit: R.J. Reynolds Tobacco Company, Bugwood.org)

Brown Spot Disease in Soybeans close up

How to Identify Brown Spot Disease

The disease presents as small, dark brown spots on both upper and lower leaf surfaces. These spots, usually 2-5mm in diameter, can coalesce to form larger blotches.

As the disease evolves, the infected leaves turn yellow and may prematurely fall from the plant. In extreme cases, Brown Spot can cause defoliation of lower leaves, leading to a decrease in yield.

Geographic Impact of Brown Spot Disease

Brown Spot thrives in warm, humid climates and often hits hardest in fields with a history of soybean cultivation. The disease can persist in infected crop residue, making it a perennial issue in fields where soybeans are the primary crop.

(Image Credit: R.J. Reynolds Tobacco Company, Bugwood.org)

R.J. Reynolds Tobacco Company, Bugwood.org

Timing of Brown Spot Disease

Brown spot typically makes its appearance early in the growing season, often as the first foliar disease. However, it can also strike later in the season.

How to Manage Brown Spot Disease in Soybeans

Effective management of Brown Spot is a key determinant of successful soybean production.

Many fungicides work to reduce disease. Our experts recommend applying GCS Azoxyprop during soybean growth stage R3.

Disclaimer

© 2014 - 2023 Farmer's Business Network, Inc. All rights Reserved. The sprout logo, “Farmers Business Network”, “FBN”, “FBN Direct” are trademarks or registered trademarks of Farmer's Business Network, Inc. This content was written by Norm℠, reviewed and edited by Stephanie Nikolopoulos.

This content was generated with the assistance of Norm℠, FBN’s artificial intelligence (AI) Ag Advisor, based on a dataset of information containing general industry best practices and research. The AI model did not use specific external sources to generate this content. Our process involves using AI to aid human subject matter experts with the initial drafting and/or refinement of content.

Every product that labels BROWN SPOT as a weed, pest, or disease the product can be applied against is shown below. Click any product for label and more information.
A-Zox 25SCAcadia® ESQAcadia™ 2 SCAcadia™ 2 SCAcadia™ ESQ FungicideAcropolis FungicideAcropolis™ FungicideAffiance®Affiance™Aframe™Aframe™ PlusAftershock®Alterity™ 62.5 WGAlto® 100 SLAmeriCop 40 DFAmistar® TopAndiamo® 230 FungicideAndiamo™ 230 FungicideAproach®Aproach® PrimaAprovia® Top FungicideAquila™ XLArius™ 250Arius™ ADV FungicideArius™ AdvanceArysta Propiconazole 41.8 EC FungicideAvaris® 2XSAvaris™ FungicideAviv™Aviv™Azoxy TebAzoxyStar®Azoxystrobin 100 STAzoxystrobin SCAZterknot®AZteroid® FCAZteroid® FC 3.3BacixBadge® SCBadge® SCBadge® SCBadge® X2Badge® X2Badge® X2Ballad® PlusBasic Copper 53BonafideBrixen™ FungicideBrixen™ FungicideBumper®Bumper® 41.8 ECBumper® ESCaptan 38.75% FLCaptan 4LCaptan 50 Wettable PowderCaptan 50WCaptan 50WPCaptan 80 WDGCaptan 80 WDGCaptan 80 WDG FungicideCaptan Gold® 4LCaptec 4L®Cercobin® FungicideCercobin™ FungicideCercos™ FungicideChamp® Dry PrillChamp® Formula 2 FlowableChamp® WGChampion® Wettable PowderChampION++™ Fungicide/BactericideChlorothalonil 82.5DF SelectCOC DFCopper-Count®-NCover XL (Agri Star)Crossover® ProCueva® Fungicide ConcentrateCuprofix® Ultra 40 Disperss®Cuproxat® Flowable Copper FungicideCustodia®Delaro® 325 SC FungicideDelaro® CompleteDexter® SCDomark® 230 MEDomark® 230 ME FungicideDouble Nickel 55™Double Nickel® LCDynasty®Echo® 720 Agricultural FungicideEcho® 90DF Agricultural FungicideEcho® Zn Agricultural FungicideEmpireEndura® fungicideEquation™Equation™ SC FungicideEsquire™Evito® 480 SCEvito® T FungicideFitness® FungicideFortix® FungicideFroghorn™GCS Azoxy 2SCGCS AzoxypropGCS Tebustrobin SCGold Rush®Guarda®Headline® fungicideHeadline® SC fungicideHeads Up® RTA Seed TreatmentHelena® ProPhyt®Helena® T-Methyl 4.5 AgHelmstar Plus SCHowler® EVOHowler® FungicideIncognito® 4.5 FIncognito® 85 WDGKalmor®Kentan® DFKocide® 2000Kocide® 2000Kocide® 2000-OKocide® 3000Kocide® 3000Kocide® 3000-OKocide® DFKOP-Hydroxide™KOP-Hydroxide™ 50WKOP™-5 Algaecide/Bactericide/FungicideLucento™Luna® FlexLuna® PrivilegeLuna® ProLuna® TranquilityMagistrate™Marazo™MasterCop®Mazinga™ ADV FungicideMazolin™MiCrop™ FungicideMiCrop™ FungicideMinerva® DuoMiramar™ FungicideMiravis® NeoMiravis® PrimeMiravis® TopMiricell™Nordox®Nordox® 75 WGNu-Cop 50 WPNu-Cop® 30 HBNu-Cop® 3LNu-Cop® 50DFNu-Cop® HBNu-Cop® XLRNufarm T-Methyl 4.5 F FungicideNufarm T-Methyl 70 WSB FungicideOmni® Brand Propiconazole 41.8% ECOmni® Brand T-Methyl 70 WPOrbus™ ESQOverrule®OxiDate® 2.0OxiDate® 5.0PeroxySan-CX Broad Spectrum Bactericide/FungicidePPZ 41.8 Select™Preemptor® EQPreemptor™ SC FungicidePrevisto®Priaxor® D {Component B}Priaxor® D fungicidePriaxor® Xemium® brand fungicideProline® 480 SCPropazPropi-Star® ECPropicon ECPropiconazole 3.6 EC FungicidePropicure 3.6FPropiMax® EC FungicidePropulse®Protegam® YLDProtocol®Provysol™ fungicideProzio™ SCQuadris Top®Quadris Top® SBQuadris Top® SBXQuadris® FlowableQuash® FungicideQuash® SC FungicideQuilt Xcel®Quilt® FungicideRadius™ ESQReckoning FungicideRegalia®Regalia® Rx BiofungicideRegev®Rendition™Reveille®Revus Top®Revylok™ FungicideRevytek™ fungicideRomeoSatori® FungicideSaxony 100 FSScala® SCSerenade® ASOSerifel® BiofungicideShar-Shield PPZSlant™Slant™ ECSonata®SporeQuell™ 15%Stratego®Stratego® YLDTalaris™ 4.5 FTalaris™ 70 WSBTanos®Tarian™TebazTepera® PlusTepera® Plus HDTepera® Plus HDTepera™Tetraban®Tetraban® FungicideThiophanate Methyl 85 WDGTide Propiconazole 41.8% EC FungicideTilt®Topaz® FungicideTopGuard® EQ FungicideTopsin® 4.5FL FungicideTopsin® M WSB FungicideTopsin® XTR2 FungicideTop™ MPTrevo®Trevo® DCZTrevo® PTrevo® PackedTrevo® TRZTrivapro® FungicideTrivapro™ ATrivapro™ BVacciplant®Vacciplant®Vango™ ESQVango™ WGVeltyma® fungicideVertisan®Viatude™ FungicideVigilWillowood Azoxy 2SCWillowood AzoxyProp XtraWillowood Propicon 3.6ECWillowood Pyrac 2ECWillowood Tebustrobin SCXiphosin™XuviaZeroTol® HCZing!®Zolera™ FX Fungicide