Evaluation of Pathogenicity of Bipolaris and Curvularia spp. on Dwarf and Ultradwarf Bermudagrasses in Florida

Abstract

Isolates of Curvularia lunata, C. geniculata, Bipolaris hawaiiensis, and B. cynodontis were tested for pathogenicity on the hybrid bermudagrass cultivars Tifdwarf, TifEagle, and FloraDwarf at 20 and 30°C. Curvularia lunata, C. geniculata, and B. hawaiiensis produced some minor leaf tip necrosis at the cut ends of leaves 24 to 48 h after inoculation. Bipolaris cynodontis produced significant tip dieback and leaf spotting on all three cultivars at both 20 and 30°C, and disease severity was higher at 20°C than at 30°C. With C. lunata, C. geniculata, and B. hawaiiensis, occasional leaf-spotting occurred only on senescing, older leaves. Bipolaris cynodontis is considered pathogenic on bermudagrasses, while C. lunata, C. geniculata, and B. hawaiiensis are considered senectopathic, able to incite disease only in senescing plant tissue. Curvularia lunata and B. hawaiiensis resulted in higher disease severity at 30°C than at 20°C, indicating that these species are senectopathic at higher temperatures. Accepted for publication 29 September 2006. Published 19 January 2007.

Cultivar Selection, Cultural Management Practice, and Fungicide Application Influence Leaf Spot and Dollar Spot on Ultradwarf Bermudagrass

“…This indicates that MiniVerde may have increased field tolerance to both B. cynodontis and S. homoeocarpa , compared with Champion, when managed under similar conditions. To our knowledge, these UDB cultivars have not been evaluated for resistance to foliar diseases; however, another study demonstrated an increased leaf spot susceptibility of FloraDwarf compared with TifEagle and Tifdwarf cultivars (Brecht et al, 2007). Results of this study, together with previous studies, indicate that variation in disease resistance likely exists among modern UDB cultivars (Bonos et al, 2003; Brecht et al, 2007; Bonos and Weibel, 2008; Tomaso‐Peterson and Young, 2010; Steketee et al, 2016).…”

“…Leaf spot, caused by Bipolaris cynodontis (Marignoni) Shoemaker, and dollar spot, caused by Sclerotinia homoeocarpa F.T. Bennett, are two diseases that affect UDB putting green turf (Couch, 1995; Taliaferro, 1995; Walsh et al, 1999; Couch, 2000; Smiley et al, 2005; Brecht et al, 2007; Andrae et al, 2009; Latin, 2011).…”

“…Management programs for turfgrass diseases include the use of resistant turfgrass cultivars, cultural management practices, and chemical pesticide applications (Vargas, 1993; Couch, 1995; Latin, 2011). Host resistant cultivar selection has been demonstrated in many host‐pathogen interactions; however, the usefulness of this approach is dependent on the availability of host resistance to a particular disease (Couch, 1995; Brecht et al, 2007; Bonos and Weibel, 2008; Tomaso‐Peterson and Young, 2010; Watschke et al, 2013). Research of host resistance to turfgrass diseases among UDB cultivars is limited; however, studies in other cool‐ and warm‐season turfgrass species provide a basis for such investigations (Bonos et al, 2003; Brecht et al, 2007; Bonos and Weibel, 2008; Tomaso‐Peterson and Young, 2010; Steketee et al, 2016).…”

“…1995; Walsh et al, 1999;Couch, 2000;Smiley et al, 2005;Brecht et al, 2007;Andrae et al, 2009;Latin, 2011).…”

Bipolaris spicifera isolates with unusual conidial germination pattern on sunflower from Iran

“…Until now over 100 species of Bipolaris have been described (Brecht 2005, Crous et al 2004). The present species is similar to B. spicifera in all essential features, but it differs from the type specimen of this fungus in conidial germination pattern; in our isolates conidia germinate to form swollen germ tubes from both ends and swollen germ tube undergo multiple branching soon after formation.…”