The extent to which gray leaf spot damages crop yields can be estimated based on the extent to which leaves are infected relative to grainfill ().Damage can be more severe when developing lesions progress past the ear leaf around pollination time. Accepted June 22, 2010 The efficacy of leaf extracts of Gliricidia sepium, Tithonia diversifolia, Phyllanthus amarus and Morinda lucida were assessed in vitro to control Curvularia lunata. The causal organism of sugarcane leaf blight and the taxonomic status of the pathogen involved were, therefore, reinvestigated. Gray leaf spot of corn is caused by a fungal pathogen Cercospora zeae-maydis (Syn. Root-knot Meloidogyne spp. The disease is caused by Cochliobolus lunatus (syn. Gray leaf spot lesions on corn leaves hinder photosynthetic activity, reducing carbohydrates allocated towards grain fill. Although both diseases are restricted by leaf veins, the margins of BLS lesions are irregular, whilst those of GLS have a rectangular appearance (Photo 3). Cercospora zeina is the causal agent of grey leaf spot disease of maize in southern Africa. Nematodes, parasitic. The aim of our study was to identify the causal agent of grey leaf spot disease of maize in southern Africa. Lesions are about 0.5 cm in diameter when fully developed. Lesions are pale brown or grey to tan, long, narrow and rectangular, being characteristically restricted by veins 2. Spot-causing fungal disease occurring increasingly mainly in the cool region. Mycosphaerella spp). Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated. 2009; 124:577–583. Contents1 Stem rot of rice management1.1 Causal organism of Stem … Stem rot of rice management Contents1 FrogEye Leaf spot 1.1 Symptoms of FrogEye Leaf spot Tobacco1.2 … Symptoms and Signs. Symptoms • Brown spots develop on the margin and at the tip of the leaf lamina. Eur J Plant Pathol. The disease is spreading to neighbouring provinces and countries. Disease name: Mango Grey Blight Causal Organism: Pestalotiopsis mangiferae Pestalotia mangiferae (Syn) Other names: Pestalotiopsis Leaf Spot of mango Report: First reported by Hennings in Taiwan at 1909. Grey leaf spot (GLS), caused by Cercospora zeae-maydis or Cercospora zeina, is a highly destructive foliar disease worldwide. The pustules are generally small, less than 0.6 cm, and are surrounded by the leaf epidermal layer which appears as a whitish covering. Abstract: Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated. Single-conidial cultures were recovered from maize leaves with typical disease symptoms sampled from several fields in South Africa, Zambia A study was launched to investigate strategies that could be adopted to facilitate the continuation of conservation tillage practices without exposing maize to unnecessarily high risk from GLS. Northern leaf spot (=Helminthosporium leaf spot) Causal organism: Cochliobolus carbonum Nelson, Ascomycotina . The spores became brownish-black when they mature. Keywords: Gray leaf spot, Grey leaf spot, GLS, Cercospora, QTL, Maize, Corn Background Gray leaf spot (GLS) is a foliar disease of maize that was highlighted as a threat to maize production in the USA in the 1980s [1], reported in South Africa in the 1990s [2], and currently has a worldwide distribution in maize production areas, including South America [3] and China [4]. Maize chlorotic dwarf Maize chlorotic dwarf virus (MCDV) Maize chlorotic mottle Maize chlorotic mottle virus (MCMV) Maize dwarf mosaic Maize dwarf mosaic virus (MDMV) strains A, D, E and F Maize leaf fleck Maize leaf fleck virus (MLFV) Maize line* Maize line virus (MLV) Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated. Causal Organism. Curvularia lunata ), Pseudocochliobolus pallescens (syn. Stud Mycol. Symptoms: Disease is characterized by long elliptical greyish-green or tan lesions on the leaves measuring 2.5 to 25 cm in length and up to 4 cm in width. Ring Criconemella spp. Starts on lower leaves progressing upwards Management and Control 1. Needle Longidorus africanus and other species Pin Paratylenchus spp. 2006; 55:189–197. 1. Maize leaf showing symptoms of Curvularia leaf spot: small necrotic or chlorotic spots with a light colored halo. Gray leaf spot starts as small necrotic (dead tissue) light-tan spots. Reniform Rotylenchus spp. Sting Belonolaimus … 892. E-mail: foyedeji@yahoo.com. Grow Seed Co tolerant hybrids 2. Two potential sibling species have been recognized as Groups I and II. Symptoms and Management of FrogEye Leaf spot Tobacco: Causal organism: Cercospora nicotianae. These expand in length to become rectangular and can reach 2 inches but they are limited within leaf veins (regular). Two potential sibling species have been recognized as Groups I and II. Grey leaf spot disease (GLS), Cercospora zeae-maydis, which has previously been attributed to diverse pathogen species in other countries, has become a serious biotic constraint to production of maize (Zea mays L.) in Kenya. Nematodes, parasitic; Awl Dolichodorus spp. Curvularia maculans). Curvularia pallescens ), and >Pseudocochliobolus eragrostidis (syn. In recent years, gray leaf spot (GLS) has become a major yield‐limiting disease, resulting in grain yield losses as high as 60% in high yield potential maize (Zea mays L.) production areas. Maize Leaf Spot Causal Organism masuzi January 20, 2020 Uncategorized 0 Northern corn leaf spot umn extension gray leaf spot of corn ohioline northern corn leaf blight pioneer seeds leaf blight of maize … I MPORTANC. Species of Cercospora associated with grey leaf spot of maize. Grey Leaf Spot. Models were developed to assess the risk and predict the severity of gray leaf spot of maize, and to describe relationships between environmental variables and the rate of lesion expansion and sporulation of the causal organism, Cercospora zeae-maydis. Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated. Single-conidial cultures were recovered from maize leaves with typical disease symptoms sampled from several fields in South Africa, Zambia and Zimbabwe. Maize bushy stunt Mycoplasmalike organism (MLO), assoc. Spiral Helicotylenchus spp. The genetic basis of GLS resistance was dissected using two DH populations sharing a common resistant parent. The causal organism associated with the disease is Cercospora zeae-maydis. Crous PW, Groenewald JZ, Groenewald M, Caldwell P, Braun U, Harrington TC. Two potential sibling species have been recognized as Groups I and II. The causal organism a… ... BLS disease symptoms can easily be confused with that of a fungal disease named grey leaf spot (GLS). Phaeosphaeria leaf spot CAUSAL ORGANISM Fungus: Phaeosphaeria maydis and Phoma sorghina (possible disease complex). Zonate leaf spot and sheath blight Gloeocercospora sorghi. Blighted sugarcane leaves were collected from 25 locations, and 1 Published with the approval of the Director of the Taiwan Sugar Research Institute. The spots develop into oval to elongate reddish-brown powdery and elevated lesions that contain a powdery mass of orange to reddish-brown spores on the upper and lower leaf surfaces. Two potential sibling species have been recognized as Groups I and II. Causal organism: Fungus: Cercospora zea-maydis Symptoms: 1. on Curvularia lunata, the causal organism of maize leaf spot O. The lesions may merge forming large grey blotches with irregular margins killing the leaves 3. A major QTL repeatedly detected in multiple developmental stages and environments was fine mapped in a backcross population. A. Akinbode Institute of Agricultural Research and Training, IAR&T, Ibadan, Nigeria. race 3. 1) Turcicum Leaf blight: causal organism: Helminthosporium turcicum. This study was conducted to establish solutions to the problem that could be easily implemented by maize farmers. The disease begins to occur around the rainy season and stripe lesions are produced along the midrib abundantly. doi: 10.1007/s10658-009-9443-1. Dagger, American Xiphinema americanum: Lesion Pratylenchus spp. The causal organism associated with the disease is Cercospora zeae-maydis. 3. CAUSAL ORGANISM: Exserohilum turcicum (previously called Helminthosporium turcicum) Grey-green, elliptical disease lesions begin to develop 1 to 2 weeks after infection (Figure 1). • They increase in size and become dark brown. Abstract: Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated. History and distribution of gray leaf spot of maize The first report of gray leaf spot (GLS) of maize, caused by Ce/cospora zeae-mayd/s Tehon and Daniels, dates back to 1924 when the disease was observed in Alexander County, southern Illinois (58). By 1943, the disease was observed causing extensive leaf blighting in Tennessee and Kentucky, reaching severities as i high as 94% (29). It has become well established in the province of KwaZulu-Natal, and is capable of reducing grain yields by 20 to 60%. Phaeosphaeria leaf spot (PLS) is increasingly being considered a major disease of maize in parts of South Africa, especially in KwaZulu-Natal in the mist belt, Winterton and Bergville areas and is considered a potential threat to maize production in regions … Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated.The causal organism associated with the disease is Cercospora zeae-maydis.Two potential sibling species have been recognized as Groups I and II. The causal organism associated with the disease is Cercospora zeae-maydis. BLS of maize The causal organism of BLS is Xanthomonas vasicola pv. The causal organism associated with the disease is Cercospora zeae-maydis. Abstract: Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated. Causal Organism. The fungus affects the maize plant at a young stage. Two potential sibling species have been recognized as Groups I and II. Small roundish spot are developed on the leaves, especially on The causal organism associated with the disease is Cercospora zeae-maydis. Grey leaf spot is a relatively new fungal disease of maize in South Africa. These lesions become pale gray to tan as they enlarge in size from 25 mm to 150 mm or longer (Figure 2). The aim of our study was to identify the causal agent of grey leaf spot disease of maize in southern Africa. Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated. Small yellowish round to oval spots are seen on the leaves. 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