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Effects of seed treatments and inoculum density of Fusarium avenaceum and Rhizoctonia solani on seedling blight and root rot of faba bean K. F. Chang 1 , R. L. Conner 2 , S. F. Hwang 1 , H. U. Ahmed 1 , D. L. McLaren 3 , B. D. Gossen 4 , and G. D. Turnbull 1 1 Crop Diversification Centre North, Alberta Agriculture and Rural Development, 17507 Fort Road, Edmonton, Alberta, Canada T5Y 6H3; 2 Morden Research Station, Agriculture and Agri-Food Canada, Unit 101, Route 100, Morden, Manitoba, Canada R6M 1Y5; 3 Brandon Research Centre, Agriculture and Agri-Food Canada Brandon, Manitoba, Canada R7A 5Y3; and 4 Saskatoon Research Centre, AAFC, 107 Science Place, Saskatoon, Saskatchewan, Canada S7N 0X2. Received 25 October 2013, accepted 27 January 2014. Published on the web 5 February 2014. Chang, K. F., Conner, R. L., Hwang, S. F., Ahmed, H. U., McLaren, D. L., Gossen, B. D. and Turnbull, G. D. 2014. Effects of seed treatments and inoculum density of Fusarium avenaceum and Rhizoctonia solani on seedling blight and root rot of faba bean. Can. J. Plant Sci. 94: 693700. Production of faba bean cultivars with tannin-free seed on the Canadian prairies has potential for use in human food and as a feedstock for livestock and aquaculture. However, root rot is a major constraint to production. The effects of fungicide seed treatments on root rot caused by Fusarium avenaceum and Rhizoctonia solani, and the effect of inoculum density on seedling emergence, nodulation, root rot severity and yield of faba bean were examined across 12 station years from 2009 to 2011 at sites in Manitoba and Alberta. Fusarium avenaceum reduced seedling emergence more than R. solani, but both pathogens had a similar impact on seed yield. The effects of inoculum density and seed treatment were generally significant for seedling emergence, root rot severity and seed yield for both pathogens. The interaction effects of inoculum density seed treatment for F. avenaceum and R. solani were only significant for seed yield and seedling emergence. Seedling emergence and seed yield declined with increasing inoculum level for both F. avenaceum and R. solani. Fungicidal seed treatments with Apron Maxx (fludioxonilmetalaxyl) and Vitaflo 280 (carbathiinthiram) consistently improved emergence and seed yield in trials inoculated with F. avenaceum or R. solani. This study demonstrated that seed treatment to manage root rot of faba bean is warranted. Key words: Vicia faba, Fusarium avenaceum, Rhizoctonia solani, yield loss, inoculum density, seed treatment, fungicide Chang, K. F., Conner, R. L., Hwang, S. F., Ahmed, H. U., McLaren, D. L., Gossen, B. D. et Turnbull, G. D. 2014. Incidence du traitement des semences et de la densite´ de l’inoculum de Fusarium avenaceum et de Rhizoctonia solani sur la fonte des semis et le pie´tin chez la fe`verole. Can. J. Plant Sci. 94: 693700. L’hybridation de cultivars de fe`verole sans acide tannique laisse entrevoir des possibilite´s dans les Prairies canadiennes, car on pourrait se servir de cette culture pour l’alimentation humaine ou comme provende, en e´levage et en aquiculture. Le pie´tin constitue ne´anmoins un obstacle majeur. De 2009 a` 2011,les auteurs ont e´tudie´ les effets dutraitement des semences avec un fongicide sur le pie´tin cause´ par Fusarium avenaceum et Rhizoctonia solani, ainsi que l’incidence de la densite´ de l’inoculum sur la leve´e, la nodulation, la gravite´ du pie´tin et le rendement de la fe`verole dans 12 stations-anne´es, a` divers sites du Manitoba et de l’Alberta. Fusarium avenaceum diminue plus la leve´e que R. solani, mais les deux pathoge`nes ont un impact analogue sur le rendement grainier. En ge´ne´ral, la densite´ de l’inoculum et le traitement des semences ont un effet significatif sur la leve´e, la gravite´ du pie´tin et le rendement grainier, pour les deux pathoge`nes. L’interaction de la densite´ de l’inoculum avec le traitement des semences contre F. avenaceum et R. solani n’a un effet significatif que sur le rendement grainier et la leve´e. La leve´e et le rendement grainier diminuent avec la dose de l’inoculum de F. avenaceum et de R. solani. Traiter les semences avec un fongicide comme Apron Maxx (fludioxonilme´talaxyl) ou Vitaflo 280 (carbathiinethiram) a constamment ame´liore´ la leve´e et le rendement grainier dans les essais avec inoculation de F. avenaceum ou R. solani. Cette e´tude montre qu’il est justifie´ de lutter contre le pie´tin de la fe`verole par le conditionnement des semences. Mots cle ´s: Vicia faba, Fusarium avenaceum, Rhizoctonia solani, perte de rendement, densite´ de l’inoculum, traitement des semences, fongicide Production of faba bean (Vicia faba L.) cultivars with tannin-free seed on the Canadian prairies has potential for use in human food, as a feedstock for livestock and in aquaculture (Cre´pon et al. 2010), and as a forage crop (Strydhorst et al. 2008). Production costs are similar to those of field pea, but yield potential is higher than for pea and other pulses. However, tannin-free faba bean cultivars have a thin seed coat with low concentrations of saponins and alkaloids. This increases susceptibility to severe seedling blight and root rot (Kantar et al. 1996). Therefore root rot diseases could be a major constraint to the long-term production of faba bean (Fig. 1). Can. J. Plant Sci. (2014) 94: 693700 doi:10.4141/CJPS2013-339 693 Can. J. Plant Sci. Downloaded from pubs.aic.ca by Depository Services Program on 10/28/14 For personal use only.

Effects of seed treatments and inoculum density of Fusarium avenaceum and Rhizoctonia solani on seedling blight and root rot of faba bean

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Page 1: Effects of seed treatments and inoculum density of Fusarium avenaceum and Rhizoctonia solani on seedling blight and root rot of faba bean

Effects of seed treatments and inoculum density ofFusarium avenaceum and Rhizoctonia solani on seedling

blight and root rot of faba bean

K. F. Chang1, R. L. Conner2, S. F. Hwang1, H. U. Ahmed1, D. L. McLaren3,B. D. Gossen4, and G. D. Turnbull1

1Crop Diversification Centre North, Alberta Agriculture and Rural Development, 17507 Fort Road, Edmonton,Alberta, Canada T5Y 6H3; 2Morden Research Station, Agriculture and Agri-Food Canada, Unit 101,

Route 100, Morden, Manitoba, Canada R6M 1Y5; 3Brandon Research Centre, Agriculture and Agri-FoodCanada Brandon, Manitoba, Canada R7A 5Y3; and 4Saskatoon Research Centre, AAFC,

107 Science Place, Saskatoon, Saskatchewan, Canada S7N 0X2.Received 25 October 2013, accepted 27 January 2014. Published on the web 5 February 2014.

Chang, K. F., Conner, R. L., Hwang, S. F., Ahmed, H. U., McLaren, D. L., Gossen, B. D. and Turnbull, G. D. 2014.Effects of seed treatments and inoculum density of Fusarium avenaceum and Rhizoctonia solani on seedling blight and root rot

of faba bean. Can. J. Plant Sci. 94: 693�700. Production of faba bean cultivars with tannin-free seed on the Canadianprairies has potential for use in human food and as a feedstock for livestock and aquaculture. However, root rot is a majorconstraint to production. The effects of fungicide seed treatments on root rot caused by Fusarium avenaceum andRhizoctonia solani, and the effect of inoculum density on seedling emergence, nodulation, root rot severity and yield of fababean were examined across 12 station years from 2009 to 2011 at sites in Manitoba and Alberta. Fusarium avenaceumreduced seedling emergence more than R. solani, but both pathogens had a similar impact on seed yield. The effects ofinoculum density and seed treatment were generally significant for seedling emergence, root rot severity and seed yield forboth pathogens. The interaction effects of inoculum density�seed treatment for F. avenaceum and R. solani were onlysignificant for seed yield and seedling emergence. Seedling emergence and seed yield declined with increasing inoculumlevel for both F. avenaceum and R. solani. Fungicidal seed treatments with Apron Maxx (fludioxonil�metalaxyl) andVitaflo 280 (carbathiin�thiram) consistently improved emergence and seed yield in trials inoculated with F. avenaceum orR. solani. This study demonstrated that seed treatment to manage root rot of faba bean is warranted.

Key words: Vicia faba, Fusarium avenaceum, Rhizoctonia solani, yield loss, inoculum density, seed treatment, fungicide

Chang, K. F., Conner, R. L., Hwang, S. F., Ahmed, H. U., McLaren, D. L., Gossen, B. D. et Turnbull, G. D. 2014.Incidence du traitement des semences et de la densite de l’inoculum de Fusarium avenaceum et de Rhizoctonia solani sur lafonte des semis et le pietin chez la feverole. Can. J. Plant Sci. 94: 693�700. L’hybridation de cultivars de feverole sans acidetannique laisse entrevoir des possibilites dans les Prairies canadiennes, car on pourrait se servir de cette culture pourl’alimentation humaine ou comme provende, en elevage et en aquiculture. Le pietin constitue neanmoins un obstaclemajeur. De 2009 a 2011, les auteurs ont etudie les effets du traitement des semences avec un fongicide sur le pietin cause parFusarium avenaceum et Rhizoctonia solani, ainsi que l’incidence de la densite de l’inoculum sur la levee, la nodulation, lagravite du pietin et le rendement de la feverole dans 12 stations-annees, a divers sites du Manitoba et de l’Alberta. Fusariumavenaceum diminue plus la levee que R. solani, mais les deux pathogenes ont un impact analogue sur le rendement grainier.En general, la densite de l’inoculum et le traitement des semences ont un effet significatif sur la levee, la gravite du pietin etle rendement grainier, pour les deux pathogenes. L’interaction de la densite de l’inoculum avec le traitement des semencescontre F. avenaceum et R. solani n’a un effet significatif que sur le rendement grainier et la levee. La levee et le rendementgrainier diminuent avec la dose de l’inoculum de F. avenaceum et de R. solani. Traiter les semences avec un fongicidecomme Apron Maxx (fludioxonil�metalaxyl) ou Vitaflo 280 (carbathiine�thiram) a constamment ameliore la levee et lerendement grainier dans les essais avec inoculation de F. avenaceum ou R. solani. Cette etude montre qu’il est justifie delutter contre le pietin de la feverole par le conditionnement des semences.

Mots cles: Vicia faba, Fusarium avenaceum, Rhizoctonia solani, perte de rendement, densite de l’inoculum,traitement des semences, fongicide

Production of faba bean (Vicia faba L.) cultivars withtannin-free seed on the Canadian prairies has potentialfor use in human food, as a feedstock for livestock and inaquaculture (Crepon et al. 2010), and as a forage crop(Strydhorst et al. 2008). Production costs are similar tothose of field pea, but yield potential is higher than for

pea and other pulses. However, tannin-free faba beancultivars have a thin seed coat with low concentrations ofsaponins and alkaloids. This increases susceptibility tosevere seedling blight and root rot (Kantar et al. 1996).Therefore root rot diseases could be a major constraintto the long-term production of faba bean (Fig. 1).

Can. J. Plant Sci. (2014) 94: 693�700 doi:10.4141/CJPS2013-339 693

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Page 2: Effects of seed treatments and inoculum density of Fusarium avenaceum and Rhizoctonia solani on seedling blight and root rot of faba bean

More than 13 species of Fusarium have been reportedto cause root rot of faba bean, including F. oxysporum(Schlecht) Snyder et Hansen (Gennari 1984; Simay 1986),F. solani (Mart.) Sacc. (Ibrahim and Hussein 1974;Abou-Zeid et al. 1997), F. avenaceum, F. acuminatumEll. & Ev., F. equiseti (Corda) Sacc. sensu Gordon, F.graminearum Schwabe, F. nygamai Burgess & Trimboli,sp. nov., F. semitectum Berk. & Ravenel, Grevillea andF. tricinctum (Corda) Sacc. (Arestegui and Dongo 1974;Clarkson 1978; Ibrahim and Owen 1981; Yehia et al.1982; Liang 1989; Bao and Wang 1991; Sadowski 1998;Kurmut et al. 2002). A wilt and root rot complex inSyria has been reported to comprise such species as F.oxysporum Schlecht. and Macrophomina phaseolina(Tassi) Goid. (Akem and Bellar 1999). Rhizoctonia solaniand Pythium spp. have also been reported to occurin association with Fusarium root rot of faba bean(Sepulveda 1991; Erper et al. 2008). The fungi Cylindro-cladium floridanum Sob. and Seymour (Ohto and Naito1995) and Aphanomyces euteiches Drechs. (Lamari andBernier 1985; Leur et al. 2008) have also been reportedas root pathogens of faba bean.

Surveys showed that Fusarium (20%) and Rhizocto-nia (60%) root and foot rots were major diseases of fababean in Saskatchewan (McKenzie andMorrall 1975) andAphanomyces euteiches Drechs., Fusarium avenaceum(Fr.) Sacc. and Rhizoctonia solani Kuhn were associatedwith seedling blight and root rot of faba bean inManitoba (Lamari and Bernier 1985). In Alberta, rootrot affected 40% of faba bean fields in 1978 and 70% offields in 1979 (Sumar et al. 1981). Surveys from 2004 to2006 showed that fusarium root rot continued to be animportant disease of faba bean in central Alberta (Changet al. 2010).

Several studies have investigated the effect of seedtreatment with synthetic and biofungicides to manageseedling diseases and root rot of faba bean. In one study,the effect of bio-priming (a seed treatment system thatintegrates the biological and physiological aspects ofdisease control) of seed with biofungicides against rootrot pathogens including F. solani andR. solaniwas evalu-ated under greenhouse conditions.Each of the biocontrolagents examined (Trichoderma viride, T. harzianum,Bacillus cereus, B. subtilis, Pseudomonas fluorescens andT. hamatum) improved seedling emergence and reducedroot rot (El-Mougy and Abdel-Kader 2008).

In another study, the efficacy of several fungicidesand three biofungicides (T. harzianum, T. viride and T.virens) was assessed against F. oxysporum and R. solani(El-Aal et al. 2010). Seed treatment with fungicidesimproved plant growth, but combining the fungicideswith T. harzianum produced the greatest enhancementof growth. Similarly, application of T. harzianum to thesoil reduces root rot incidence more than the fungicideRizolex-T (Abdel-Kader 1997).

In western Canada, seed treatment to manage seedlingblight and root rot is an important component of pro-duction of field pea (Pisum sativum L.) (Slinkard et al.1977; Ali-Khan and Zimmer 1980), lentil (Lens culinarisL.) (Alberta Agriculture 1980; Slinkard and Drew 1981),lupin (Lupinus angustifolius L.) (Chang et al. 2011) andfaba bean (Manitoba Agriculture 1981; Rowland andDrew 1982). Several fungicides, such as Apron Maxx(metalaxyl, 1.1%�fludioxonil, 0.73%), are registeredin Canada to reduce the impact of soil-borne pathogenson pulse crops, including faba bean, while Vitaflo 280(carboxin, 15.59%�thiram, 13.25%), Thiram (thiram,75%), Trilex EverGol (penflufen, 154 g L�1�triflox-ystrobin, 154 g L�1�metalaxyl, 317 g L�1) and TrilexAL (trifloxystrobin, 13.5 g L�1�metalaxyl, 10.8 g L�1)are registered for control of seedling blight on other pulsecrops (Alberta Agriculture 2013b).

This study was undertaken to evaluate the efficacy ofseed-treatment fungicides and the interactions of fungi-cidal seed treatments with pathogen inoculum levels onseedling emergence, nodulation, root rot severity andyield of faba bean.

Fig. 1. Healthy faba bean plants showing profuse podding(A and B); a faba bean field affected by root rot (C).

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Page 3: Effects of seed treatments and inoculum density of Fusarium avenaceum and Rhizoctonia solani on seedling blight and root rot of faba bean

MATERIALS AND METHODSIsolates of F. avenaceum and R. solani were obtainedfrom symptomatic roots of faba bean plants collectedfrom a survey of commercial fields conducted in centralAlberta in 2009 and reported by Chang et al. (2010). Thesamples were surface-sterilized in 0.6% sodium hypo-chlorite for 1 min, rinsed in sterilized tap water, andplaced on acidified potato dextrose agar. After the fungalcolonies appeared, those with characteristics of Fusariumwere plated onto pentachloronitrobenzene medium(Nash and Snyder 1962) and those of Rhizoctonia werefurther purified on acidified potato dextrose agar byhyphal tip culture. To determine virulence on faba beanseedlings, mycelial plugs from actively growing Fusariumor Rhizoctonia cultures were used to inoculate polyethy-lene bags filled with 1.5 L of autoclaved wheat grain andallowed to incubate in dark conditions (covered witha dark plastic sheet) at ambient temperature for 2 wk,until the grains were completely colonized by the fungus.The infested wheat grain was air-dried, ground into apowder, and stored at 48C until it was used as inoculum.

Faba bean seeds were sown into 15-cm pots filled witha steam-pasteurized soil mixture. The seeds were coveredby the same soil mixture into which 5 mL of inoculumhad been introduced. Pathogenicity was determined bycomparing seedling survival among the inocula, and themost pathogenic of the Fusarium andRhizoctonia isolateswere selected for use in this study. The inocula for use inthe field studies in this project were prepared as describedpreviously.

Seed of the faba bean cv. Snowbird was treated in aHege small-batch seed treater (Wintersteiger, Salt LakeCity, UT) with Apron Maxx (Syngenta Crop Protection,Inc., Greensboro, NC) at 3.25 mL kg�1 seed, Thiram(Bayer CropScience, Campbellville, ON) at 1.2 g kg�1

seed, or with Vitaflo 280 (Bayer CropScience) at 3.3 mLkg�1 seed. Field trials were established on 2004 May 19at Lacombe, AB, in a Black Chernozemic clay-loam soiland on 2005 May 13 at Vegreville, AB, in a BlackChernozemic sandy-loam soil. The plots were arranged ina split-plot design with four replications. Main plottreatments were inoculation with F. avenaceum, R. solaniand a non-inoculated control. Subplots consisted of theseed treatments listed above or a non-treated control.Each subplot consisted of four, 6-m rows of plants,spaced 20 cm apart, and seeded at a rate of 75 seeds per6 m row at 5 cm depth. The powdered inoculum wasmixed and planted with the seed at 15 mL row�1 for R.solani or 30mL row�1 for F. avenaceum. These rates wereselected based on previous studies with other pulse crops(Chang et al. 2004). The seed was planted at a depth of5 cm and a rate of 75 seeds per 6-m row. Rhizobiuminoculant (Becker-Underwood, Saskatoon, SK) wasmixed and planted with the seed at a rate of 30 mLrow�1. All of the seedlings in each plot were counted onJun. 18 at both sites. The plots were harvested with asmall plot combine at crop maturity on 2004 Oct. 07 at

Lacombe and 2005 Oct. 04 at Vegreville. The seed wasdried, cleaned and weighed to estimate yield.

To assess the interaction of fungicide seed treatmentswith inoculum density of F. avenaceum and R. solani, atotal of 12 trials were conducted in 2009�2012 using thefaba bean cv. Snowbird. Trials on F. avenaceum wereconducted at Lacombe in 2010 and 2011, and at Mordenand Brandon, MB, in 2009 and 2010. Trials on R. solaniwere conducted at Lacombe in 2010 and 2011, and atMorden and Brandon in 2010 and 2012. Each trial was ina split-plot design with four replications. The main plottreatments were inoculation with either F. avenaceum orR. solani at 15, 30 or 45 mL row�1, added to the seed atthe time of planting as described previously, or a non-inoculated control. The subplots were allocated tofungicide seed treatments: Apron Maxx (3.25 mL kg�1

seed), Trilex (3.70 mL kg�1 seed), Vitaflo 280 (3.3 mLkg�1 seed), Trilex EverGol (3.7 mL 100 kg�1 seed), anda non-treated control.

The plots were seeded on 2010 May 09 (for F.avenaceum), 2010 May 18 (for R. solani) and 2011 May15 (for both pathogens) at Lacombe; on 2009 May 21(F. avenaceum), 2010 Jun. 03 (both pathogens), 2011 Jun.06 (R. solani), 2011 Jun. 10 (F. avenaceum) and 2012 Jun.06 (R. solani) at Morden; 2009 May 21 and 2010 May 14(F. avenaceum) and 2010 May 19 (R. solani) and 2011May 26 (for both pathogens) at Brandon. The seed wasplanted with inoculant as previously described and theinocula were added at the time of seeding. All of theemerged seedlings in each plot were counted at 4 wk afterseeding. Data on nodulation and root rot severity wererecorded on 2010 Aug. 10 (for both pathogens) and 2011Aug. 17 (F. avenaceum) and Aug. 18 (R. solani) atLacombe; on 2009 Jul. 01, 2010 Aug. 19 (F. avenaceum)and Aug. 25 (R. solani), and 2011 Aug. 22 (F. avenaceum)and Aug. 23 (R. solani) at Brandon; and 2009 Aug. 05(F. avenaceum), 2010 Aug. 05 (both pathogens), 2011Aug. 23 (both pathogens) and 2012 Aug. 30 (R. solani) atMorden. Plant roots were collected and assessed for rootrot severity on a pictorial 0�9 scale (Fig. 2), where: 0�seedling is well developed, no visible lesions on lowerstem and roots; 1�2�seedling has grown well, slightnecrosis or few small lesions on lower stem and roots,total infected area B5% (1) or B10% (2); 3�4�growthof the seedling is retarded, moderate necrosis, or smalllesions scattered over the lower stem and roots, totalinfected area B25% (3) or B50% (4); 5�6�seedlinggrowth is hampered, extensive necrosis, or large lesionson lower stem and roots, total infected area B75% (5) or]75% (6); 7�8�seedling growth is seriously hampered,extensive necrosis, or girdling lesions on lower stem androots, roots developed (7) or little or no roots (8); and 9�plant dead. Nodulation was assessed on a scale of 0�4(Chang et al. 2013), based on nodule number, size anddistribution on the roots (0�no nodules, 155 nodulesplant�1, 2510 nodules plant�1, 3520 nodules plant�1

and 4]20 nodules plant�1). Plants were harvested on

CHANG ET AL. * FABA BEAN ROOT ROT 695

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Page 4: Effects of seed treatments and inoculum density of Fusarium avenaceum and Rhizoctonia solani on seedling blight and root rot of faba bean

2010 Oct. 20 and 2011 Sep. 26 at Lacombe, on 2009 Sep.16, 2010 Oct. 08, 2011 Sep. 29 and 2012 Sep. 26 atMorden, and on 2009 Sep. 04, 2010 Oct. 15 (F.

avenaceum) and Oct. 14 (R. solani) and 2011 Sep. 28(for both pathogens) at Brandon. The seed was dried,cleaned and weighed to determine yield.

Fig. 2. Rating scale (0�9) for root rot severity on faba bean, where: 0�seedling is well developed, no visible lesions on lower stemand roots; 1�2�seedling has grown well, slight necrosis or few small lesions on lower stem and roots, total infected area B5% (1) orB10% (2); 3�4�growth of the seedling is retarded, moderate necrosis, or small lesions scattered over the lower stem and roots,total infected area B25% (3) or B50% (4); 5�6�seedling growth is hampered, extensive necrosis, or large lesions on lower stemand roots, total infected area B75% (5) or ]75% (6); 7�8�seedling growth is seriously hampered, extensive necrosis, or girdlinglesions on lower stem and roots, roots developed (7) or little or no roots (8); and 9�plant dead.

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Page 5: Effects of seed treatments and inoculum density of Fusarium avenaceum and Rhizoctonia solani on seedling blight and root rot of faba bean

The data were analyzed using a mixed model analysisof variance (PROC MIXED, SAS Institute, Inc. 2005;Littell et al. 2006). Replication, site-year (location�yearcombination) and their interactions were random effects,and the other classification variables were consideredas fixed effects. A macro was used with the analysis ofvariance to convert mean separation output to lettergroupings (Saxton 1998). Fixed treatment effects wereconsidered significant at PB0.05. The least significantdifferences (LSD) at P50.05 were also calculated.

RESULTSIn the seed treatment study conducted at Lacombe in2004 and Vegreville in 2005, inoculation with either path-ogen reduced seedling emergence and seed yield com-pared with the non-inoculated control (Table 1). Thefungicide seed treatments did not affect seedling emer-gence or seed yield in the non-inoculated control.

Inoculation with F. avenaceum generally reduced emer-gence slightly more than R. solani, but the effect on seedyield was similar. Also, there was a highly significant in-teraction (P50.0001) between inoculation (F. avenaceumor R. solani) and fungicide seed treatment for bothseedling emergence and seed yield. In the treatmentsinoculated with F. avenaceum, Apron Maxx and Vitaflo280 increased seedling emergence and yield comparedwith the non-treated inoculated control or Thiram. In thetreatments inoculated with R. solani, Apron Maxx andVitaflo 280 improved emergence compared with the non-treated control and Thiram, but only application ofApron Maxx increased yield.

Studies on the inoculum density of F. avenaceum wereconducted at three sites over 6 station years. The patternof response in analysis of variance differed among thefour response variables. For seedling emergence, themaineffects of inoculum density and seed treatment were

Table 1. Effect of inoculation with Fusarium avenaceum and Rhizoctonia solani and fungicide seed treatments on seedling emergence and seed yield of

faba bean at Lacombe and Vegreville, AB, in 2004 and 2005

Treatments Application rate Emergence (plants m�2) Yield (t ha�1)

InoculationNoninoculated control � 54a 4.72aFusarium avenaceum 20 mL row�1 27c 3.55bRhizoctonia solani 15 mL row�1 37b 3.83b

Seed treatmentNontreated control � 30c 3.62bApron Maxx 3.25 mL kg�1 seed 35b 4.55aThiram 1.2 g kg�1 seed 47a 3.69bVitaflo 280 2.6 mL kg�1 seed 45a 4.29a

Inoculation� seed treatmentInoculum Seed treatmentNoninoculated control Nontreated control 52ab 4.61ab

Apron Maxx 56a 5.05aThiram 54a 4.66abVitaflo 280 55a 4.60ab

Fusarium avenaceum Nontreated control 15f 2.76eApron Maxx 36cd 4.32bThiram 22ef 2.96eVitaflo 280 35d 4.18bc

Rhizoctonia solani Nontreated control 25e 3.48cdeApron Maxx 44bc 4.30bThiram 29de 3.47deVitaflo 280 40ab 4.09bcd

a�f Means in a column and category followed by the same letter do not differ based on LSD at P50.05 (n�16, four sites-years�four replications).

Table 2. Analysis of variance of pathogen, inoculum level and fungicide seed treatment on seedling emergence and nodulation, root rot severity, and seed

yield of faba bean in a field trial inoculated with Fusarium avenaceum and Rhizoctonia solani

Numerator Denominator Pr�F

Pathogen Effect DF DF Emergence Nodulation Root rot Yield

F. avenaceum Inoculum 3 437 B0.0001 0.12 0.09 B0.0001Fungicide 4 437 B0.0001 0.0006 0.003 B0.0001Inoc�Fung 12 437 0.15 0.88 0.72 0.004

R. solani Inoculum 3 451 B0.0001 0.79 B0.0001 B0.0001Fungicide 4 451 B0.0001 0.48 0.007 0.016Inoc�Fung 12 451 0.0007 0.86 0.80 0.997

CHANG ET AL. * FABA BEAN ROOT ROT 697

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highly significant, but there was no interaction (Table 2).For root rot severity and nodulation, seed treatmenthad a significant effect, but inoculum density did not. Forseed yield, there was a significant interaction between in-oculum density and seed treatment, which indicates thatthe effect of the seed treatments varied with inoculumdensity.

Seedling emergence decreased and seed yield was re-duced with increasing inoculum density of F. avenaceum,but the changes, although consistent over years, weresmall (Table 3). Root rot severity was higher comparedwith the non-inoculated control, at the highest inoculumdensity. Each of the fungicides improved seedling emer-gence compared with the non-treated inoculated control.Among the fungicide treatments, seedling emergencewas higher with Trilex EverGol, Vitaflo 280 and ApronMaxx than with Trilex AL. Trilex AL and Vitaflo in-creased nodulation compared with the inoculated con-trol, but none of the seed treatments reduced root rotseverity. Application of Trilex EverGol provided thehighest seed yield, followed by Apron Maxx and Vitaflo280. The effect of seed treatments on seed yield wasgenerally consistent except at the highest inoculumdensity, where Trilex AL had a negative effect on yield(data not shown).

Studies on the inoculum density of R. solani were alsoconducted at three sites over 6 station years and thepattern of response differed among the four responsevariables. The effects of inoculum density and seedtreatments were significant for seedling emergence, rootrot severity and seed yield, but the interaction effect ofinoculum density�seed treatment was only significantfor seedling emergence. Neither variable had an effecton nodulation (Table 2). Seedling emergence decreased,root rot severity increased, and seed yield was reducedwith increasing inoculum density. All of the seed treat-ments improved seedling emergence and seed yield.Application of Vitaflo 280 produced the highest emer-gence, followed by Trilex EverGol, Trilex AL, andApronMaxx. Application of Apron Maxx and Trilex EverGolreduced root rot severity compared with the non-treated

control. Seed yield was increased by all of the fungicidetreatments compared with the non-treated control(Table 4).

In all site-experiments, plants with root rot wereshorter and thinner than those with healthy roots, hadfewer pods per stem, and lower seed weight and yield(data not shown). Also, the seed from diseased plants orstems was often shrivelled in appearance.

DISCUSSIONFaba bean has traditionally been grown on only a smallacreage in western Canada (McKenzie and Morrall1975), but its production in Alberta is increasing due tomarketing opportunities, with the availability of newcultivars and the need for new pulse crops in rotation(Alberta Agriculture 2013a). Moreover, the developmentof zero-tannin cultivars is expected to lead to increaseddemand for faba bean and an expansion in production.Root rot is an important constraint that limits standestablishment and overall production of faba bean andmany other pulse crops grown on the Canadian prairies(Hwang et al. 1994).

Damping-off and root rot are destructive diseases ofsnap bean (P. vulgaris L.), lima bean (P. lunatus L.)and dry bean (P. vulgaris) worldwide (Miller et al. 1995)that can cause substantial yield loss (Harveson et al.2005). Salem et al. (1977) demonstrated that Rhizoctoniaroot rot reduced nodulation and nitrogen fixation of V.faba in Hungary. In Ethiopia, root rot caused by F.avenaceum reduced critical yield components for fababean, resulting in a mean yield loss of 49% (Gorfu 1993).In the current studies, seedling blight and root rot causeda mean yield loss per site of 11�20%.

The synthetic fungicides Apron Maxx, Vitaflo 280,Trilex AL and Thiram are widely used as seed treatmentsin western Canada, were readily available at the time theexperiments were carried out and have been registered foruse as seed treatments to manage seedling blight and rootrot caused by Fusarium, Rhizoctonia and Pythium spp.and other soil-borne pathogens on the major pulse cropsin Canada (Alberta Agriculture 2013b). In addition,

Table 3. Interaction of inoculum density of Fusarium avenaceum and seed treatment on the seedling emergence, root rot severity, nodulation and yield of

faba bean cv. Snowbird in trials at Lacombe, AB (2010, 2011), Morden, MB (2009, 2010), and Brandon, MB (2009, 2010)

Treatments Emergence (plants m�2) Nodulation (0�4) Root rot severity (0�9) Yield (t ha�1)

Inoculum0 mL 34a 3.0 1.8b 5.5a15 mL 31b 3.0 1.8b 5.4ab30 mL 29c 3.0 1.8b 5.2bc45 mL 27d 2.9 2.0a 5.0c

FungicideControl 24c 3.1a 1.8b 4.9cApron Maxx RTA 32a 3.0ab 1.8b 5.6abTrilex EverGol 33a 3.0ab 1.8b 5.8aTrilex AL 29b 2.9b 1.9b 4.9cVitaflo 280 32a 2.9b 2.0a 5.3b

a�d Means in a column and category followed by the same letter do not differ based on LSD at P50.05 (n�24, six sites-years�four replications).

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Trilex EverGol was only available as an experimentaltreatment formulation at the time, but still was includedin the treatments. Although all three exhibited someefficacy, Vitaflo 280 was effective against both F.avenaceum and R. solani and consistently improvedseedling emergence and seed yield in inoculated trialsacross the prairie region. This study confirmed an earlierreport that seed treatment with Vitaflo 280 and ApronMaxx consistently improved seedling emergence andseed yield in faba bean (Chang et al. 2006, 2011).Similarly, seed treatment with six fungicides increasedshoot length, dry matter weight and the chlorophyllcontent of infected broad bean plants (El-Aal et al. 2010).

In the trials examining the interaction of inoculumdensity and seed treatment, the effect of inoculum den-sity was generally small, but large populations of F.avenaceum or R. solani were observed to have a detri-mental effect on seedling establishment and yield of fababean. To reduce the probability of encountering largepopulations of these pathogens, the cropping rotationhistory of the field should be also taken into considera-tion before planting a faba bean crop. Root rot patho-gens such as F. avenaceum produce thick-walled sporesthat can persist for several years, so rotation for severalyears with non-host crops is recommended. Many rootrot pathogens infecting faba bean can also infect fieldpea, so populations of these pathogens could be elevatedin fields where field pea crops have been grown frequently(Hwang et al. 1994).

Since large volumes of faba bean seed are required toachieve target plant populations, further research shouldbe conducted to develop a comprehensive managementstrategy for seedling blight and root rot that includesseeding date/soil temperature, seed quality control andthe development of cultivar resistance to root rot toaugment the application of seed treatments examined inthis study. Application of seed treatments with fungicidesalong with avoidance of large populations of R. solani orF. avenaceum provide a basis to increase the economicreturns to faba bean growers and enhance producerinterest in the crop.

ACKNOWLEDGEMENTSThis project was financially supported by the Saskatch-ewan Pulse Growers, the Agri-Food Research andDevelopment Initiative and theManitoba Pulse GrowersAssociation. We gratefully acknowledge R. Bowness, Q.Zhou, Y. Yang, H. Fu, and T. Dubitz from AARD,Lacombe, AB, T.L. Henderson, D. Hausermann, andT.J. Kerley from AAFC Brandon,MB,W.C. Penner andD.B. Stoesz from AAFC Morden, MB, and K.A.Bassendowski from AAFC Saskatoon, SK, for theirtechnical assistance on this research study.

Abdel-Kader, M. M. 1997. Field application of Trichodermaharzianum as biocide for control bean root rot disease. Egypt.J. Phytopathol. 25: 19�25.Abou-Zeid, N. M., El-Morsy, G. A., Hassanein, A. M. and

Arafa, M. K. 1997. Major organisms causing root-rot/wilt andtheir relative importance on faba bean, lentil and chickpea.Egypt. J. Agric. Res. 75: 529�542.Akem, C. and Bellar, M. 1999. Survey of faba bean (Vicia fabaL.) diseases in the main faba bean-growing regions of Syria.Arab J. Plant Prot. 17: 113�116.Alberta Agriculture 1980. Lentil production in Alberta. AlbertaAgriculture, Edmonton, AB. Agdex 142120-5.Alberta Agriculture 2013a. Faba bean seeding management inAlberta. Alberta Agriculture, Edmonton, AB. Agdex 142/22-1.[Online] Available: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex14482/$file/142_22-1.pdf?OpenElement.Alberta Agriculture. 2013b. Crop protection 2013. H. Book andM. Cutts, eds. 540 pp. [Online] Available: www.agriculture.alberta.ca.Ali-Khan, S. T. and Zimmer, R. C. 1980. Production of fieldpeas in Canada. Agriculture Canada. Ottawa. ON. Publ. 1710.Arestegui, C. M. E. and Dongo, D. S. L. 1974. Fusarium spe-cies on broad bean (Vicia faba L.). Invest. Agropecu 4: 41�46.Bao, J. R. and Wang, G. C. 1991. Pathogenicity of Fusariumspp. associated with foot-rot of faba bean. FABIS Newsl.28�29: 32�35.Chang, K. F., Bowness, R., Hwang, S. F., Turnbull, G. D.,

Lopetinsky, K., Olson, M., Bing, D. J. and Howard, R. J. 2006.

Evaluation of fungicidal seed treatments for the control ofrhizoctonia and fusarium seedling blight of faba bean inAlberta in 2005. Pest Manag. Res. Rep. 44: 246�248.

Table 4. Interaction of inoculum density of Rhizoctonia solani and seed treatment on the seedling emergence, root rot severity, nodulation and yield of

faba bean cv. Snowbird at sites in Brandon, MB (2010, 2011), Lacombe, AB (2010, 2011), and Morden, MB (2010, 2012)

Treatments Emergence (plants m�2) Nodulation (0�4) Root rot severity (0�9) Yield (t ha�1)

Inoculum0 mL 46a 2.3 2.3c 3.7a15 mL 44b 2.3 2.6b 3.2b30 mL 43b 2.3 2.9a 3.2b45 mL 41c 2.3 3.0a 3.0c

FungicideControl 39d 2.3 2.9a 3.0bApron Maxx RTA 42c 2.4 2.4c 3.3aTrilex EverGol 45ab 2.3 2.6bc 3.3aTrilex AL 44b 2.3 2.7ab 3.3aVitaflo 280 47a 2.3 2.7ab 3.4a

a�d Means in a column and category followed by the same letter do not differ based on LSD at P50.05 (n�24, six sites-years�four replications).

CHANG ET AL. * FABA BEAN ROOT ROT 699

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Chang, K. F., Conner, R. L., McLaren, D. L., Hwang, S. F. andStrelkov, S. E. 2010. Occurrence of faba bean root rot inAlberta and Manitoba in 2009. Can. Plant Dis. Surv. 90: 133�135.Chang, K. F., Hwang, S. F., Gossen, B. D., Turnbull, G. D.,Howard, R. J. and Blade, S. F. 2004. Effects of soiltemperature, seeding depth, and seeding date on rhizoctoniaseedling blight and root rot of chickpea. Can. J. Plant Sci. 84:901�907.Chang, K. F., Hwang, S. F., Gossen, B. D., Strelkov, S. E.,

Turnbull, G. D. and Bing, D. J. 2011. Effect of seeding prac-tices, temperature and seed treatments on fusarium seedlingblight of narrow-leaved lupin. Can. J. Plant Sci. 91: 859�872.Chang, K. F., Nyandoro, R., Howard, R. J., Hwang, S. F.,

Turnbull, G. D., Laflamme, P., Strelkov, S. E. and McLaren,

D. L. 2013. Occurrence of soybean root rot in southernAlberta, Canada in 2011 and 2012. Can. Plant Dis. Surv. 93:170�173.Clarkson, J. D. S. 1978. Pathogenicity of Fusarium spp.associated with foot-rots of peas and beans. Plant Pathol. 27:110�117.Crepon, K., Marget, P., Peyronnet, C., Carrouee, B., Arese, P.

and Duc, G. 2010. Nutritional value of faba bean (Vicia fabaL.) seeds for feed and food. Field Crops Res. 115: 329�339.El-Aal, M. A. A., Morshedy, M. and Abdallah, E. A. M. 2010.

Effects of some fungicides and Trichoderma isolates onmorphological changes and biochemical characters of broadbean plants. Alex. J. Agric. Res. 55: 111�118.El-Mougy, N. S. and Abdel-Kader, M. M. 2008. Long-termactivity of bio-priming seed treatment for biological controlof faba bean root rot pathogens. Australas. Plant Pathol. 37:464�471.Erper, I., Karaca, G. H. and Ozkoc, I. 2008. Root rot diseaseincidence and severity on some legume species grown inSamsun and the fungi isolated from roots and soils. Arch.Phytopathol. Plant Prot. 41: 501�506.Gennari, M. 1984. A faba bean disease caused by Fusariumoxysporum. Inform. Fitopatol. 34: 37�38.Gorfu, D. 1993. Yield loss of faba bean caused by foot rot(Fusarium avenaceum). FABIS Newsl. 33: 24�27.Harveson, R. M., Smith, J. A. and Stroup, W. W. 2005.

Improving root health and yield of dry beans in the NebraskaPanhandle with a new technique for reducing soil compaction.Plant Dis. 89: 279�284.Hwang, S. F., Howard, R. J., Chang, K. F., Park, B. and

Burnett, P. A. 1994. Etiology and severity of fusarium root rotof lentil in Alberta. Can. J. Plant Pathol. 16: 295�303.Ibrahim, G. and Hussein, M. M. 1974. A new record of root rotof broad bean (Vicia faba) from the Sudan. J. Agric. Sci.(Camb.) 83: 381�383.Ibrahim, G. and Owen, H. 1981. Fusarium oxysporum, causalagent of root rot on broad bean (Vicia faba) in the Sudan.Phytopathol. Z. 101: 80�89.Kantar, F., Hebblethwaite, P. D. and Pilbeam, C. 1996. Factorsinfluencing disease resistance in high and low tannin Viciafaba. J. Agric. Sci. 127: 83�88.Kurmut, A. M., Nirenberg, H. I., Bochow, H. and Buttner, C.2002. Fusarium nygamai a causal agent of root rot of Vicia fabaL. in the Sudan. Meded. Rijksuniv. Gent. Fak. Landbouwkd.Toegep. Biol. Wet. 67: 269�274.Lamari, L. and Bernier, C. C. 1985. Etiology of seedling blightand root rot of faba bean (Vicia faba) in Manitoba, Canada.Can. J. Plant Pathol. 7: 139�145.

Leur, J. A. G. V., Southwell, R. J. and Mackie, J. M. 2008.

Aphanomyces root rot on faba bean in northern NSW.Australas. Plant Dis. Notes 3: 8�9.Liang, X. Y. 1989. Fungal diseases of faba bean in Peoples’Republic of China. FABIS Newsl. 25: 3�4.Littell, R. C., Milliken, G. A., Stroup, W. W., Wolfinger, R. D.

and Schabenberger, O. 2006. SAS for mixed models. 2nd ed.SAS Institute, Inc., Cary, NC. 813 pp.Manitoba Agriculture 1981. Fababean production and use inManitoba. Man. Dep. of Agric., Winnipeg, MB.McKenzie, D. L. and Morrall, R. A. A. 1975. Fababeandiseases in Saskatchewan in 1973. Can. Plant Dis. Surv. 55:1�7.Miller, S. A., Riedel, R. M. and Rowe, R. C. 1995.Damping-offand root rot of beans. The Ohio State University ExtensionFact Sheet HYG-3110�95. [Online] Available: http://ohioline.osu.edu/hyg-fact/3000/3110.html [2013 Aug. 12].Nash, S. M. and Snyder, W. C. 1962. Quantitative estimationsby plate counts of propagules of the bean root rot Fusarium infield soils. Phytopathology 52: 567�572.Ohto, Y. and Naito, S. 1995. Cylindrocladium root rot, a newdisease of broad bean (Vicia faba L.) caused by Cylindrocladiumfloridanum Sobers et Seymour. Ann. Rep. Soc. Plant Prot.North Jpn. 46: 53�55.Rowland, G. G. and Drew, B. N. 1982. Fababean production inSaskatchewan. University of Saskatchewan, Saskatoon, SK.Publ. No. 416.Sadowski, S. 1998. Occurrence of broad bean Vicia faba L.diseases in Olsztyn-elblag and Bydgoszcz provinces (Poland).Acta Agrobot. 41: 245�255.Salem, S. H., Hamed, A. S., Zohdy, L. and Sahab, A. F. 1977.

Effect of some pesticides on the nodulation and nitrogenfixation of infected broad bean plants with root rot and wiltdiseases. Acta Phytopath. Acad. Sci. Hun. 12: 23�30.SAS Institute, Inc. 2005. SAS online Doc 9.1.3. SAS InstituteInc., Cary, NC.Saxton, A. M. 1998. A macro for converting mean separationoutput to letter groupings in Proc Mixed. Pages 1243�1246 inProc. 23rd SAS Users Group Intl., SAS Institute, Cary, NC.Nashville, TN, 1998 Mar. 22�25. [Online] Available: http://animalscience.ag.utk.edu/facultystaff/Saxton/pdmix800.sas.Sepulveda, R. P. 1991. Identification of Rhizoctonia solaniKuhn. affecting faba bean (Vicia faba L.) in Chile. Agric. Tec.(Santiago) 51: 362�363.Simay, E. I. 1986. Occurrence of seed infection caused byFusarium oxysporum Schl. on faba bean (Vicia faba L.) seeds inHungary. Noven. 35: 119�124.Slinkard, A. E. and Drew, B. N. 1981. Lentil production inWestern Canada. University of Saskatchewan, Saskatoon, SK.Publ. 413, Agdex l49ll0.Slinkard, A. E., Drew, B. N. and Kirkland, K. J. 1977. Dry peaproduction in Saskatchewan. University of Saskatchewan,Saskatoon, SK. Publ. 225.Sumar, S. P., Howard, R. J. and Mohyuddin, M. 1981. Fababean diseases in southern Alberta 1978�79. FABIS Newsl. 3:48�49.Strydhorst, S. M., King, J. R., Lopetinsky, K. J. and Harker,

K. N. 2008. Forage potential of intercropping barley with fababean, lupin, or field pea. Agron. J. 100: 182�190.Yehia, A. H., El-Hassan, S. A., Ali, S. and Ismail, F. 1982.

Studies on root rot disease of broad bean in Iraq. Mesopota-mia J. Agric. 17: 63�70.

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