Sorghum diseases prevalent in Ghana

Field survey, screening trials and laboratory investigation were used to determine the prevalence of sorghum diseases in the major sorghum-growing climatic zones (Sudan, northern and southern Guinea savanna). Farmers\' fields were surveyed in 1997. Ten sorghum entries were evaluated under natural field conditions in 1997 and 1998 at Damongo for their reaction to foliar and panicle diseases while seed samples of field-harvested sorghum were assessed for fungal infection using the blotter method. Two main types of sorghum, viz. the early-maturing, brown-seeded, guinea or guinea-caudatum type and the late-maturing, photoperiod-sensitive, white-seeded, guinea or guinea-caudatum type were found in the sorghum-growing areas. The survey showed that sorghum was cultivated under a range of cropping systems in all possible crop mixtures. Grey leaf spot (Cercospora sorghi), oval leaf spot (Ramulispora sorghicola), zonate leaf spot (Gloeocercospora sorghi) and covered smut (Sporisorium sorghi) were prevalent in all the sorghumgrowing areas. Other diseases recorded were leaf blight (Exserohilum turcicum), sooty stripe (Ramulispora sorghi), grain mould (caused by a complex group of fungi), long smut (Sporisorium ehrenbergii), head smut (Sporisorium reiliana), rust (Puccinia purpurea) and rough leaf spot (Ascochyta sorghi). Anthracnose (Colletotrichum graminicola) occurred infrequently across the regions. Striga hermonthica was more prevalent in the two Upper regions than in the Northern Region. The sorghum entries varied considerably in their susceptibility to the field diseases, with severity mean scores ranging from 2.5 to 3.6. Eight species of fungi were recorded from seed samples. The occurrence of these varied with the sorghum entries, with the genera Fusarium and Phoma dominating, followed by Curvularia.Enquête sur le terrain, essais de dépistage et investigation de laboratoire étaient faites pour déterminer la prévalence de maladies de sorgho dans les zones climatiques principales (soudano-savane et savane guinéenne du nord et du sud) cultivant le sorgho. L\'enquête était menée en 1997 aux champs d\'agriculteurs. Dix variétés cultivées de sorgho étaient évaluées sous les conditions naturelles au champ en 1997 et 1998 à Damongo pour leur réactions aux maladies foliaires et aux maladies de panicules alors que les échantillons de graine de sorgho moissonnée de champ étaient évalués pour infection fongique en employant la méthode de buvard. Deux types principaux de sorgho à savoir la maturation tôt: graine-brune, guinée ou le type caudatum guinéen et la maturation tardive: sensible à la photopériode, graine-blanche, guinée ou le type caudatum guinéen étaient rencontrés dans les zones cultivant le sorgho. L\'enquête révélait que le sorgho est cultivé sous les systèmes de culture divers dans toutes les associations des cultures possibles. La tache à feuille grise (Cercospora sorghi), la tache à feuille ovale (Ramulispora sorghicola), la tache à feuille zonée (Gloeocercospora sorghi) et le couvert de charbon des céréales (Sporisorium sorghi) étaient en prévalence dans toutes les zones cultivant le sorgho. D\'autres maladies observées étaient la rouille des feuilles (Exserohilum turcicum) la rayure de suie (Ramulispora sorghi) la moisissure de grain (causée par un groupe complexe de fongus), le charbon long des céréales (Sporisorium ehrenbergii), le charbon de tête (Sporisorium reiliana), la rouille (Puccinia purpurea) et la tache à feuille rugueuse (Ascochyta sorghi). Anthracnose (Colletotrichum graminicola) se produit peu souvent à travers les régions. Striga hermonthica était la plus en prévalence dans les deux Hautes régions que dans la Région du Nord. Les variétés cultivées de sorgho variaient considérablement en leur prédisposition aux maladies du champ avec les résultats moyens de sévérité variant entre 2.5 et 3.6. Huit espèces de fongus étaient observées d\'ehantillons de graine. L\'apparition de ceux-ci variait avec les genres Fusarium et Phoma dominant, suivi par Curvularia. Ghana Journal of Agricultural Science Vol. 40 (2) 2008: pp. 119-12

Sources of resistance to downy mildew, smut and ergot of pearl millet and their stability in Ghana

No Abstract. Agricultural and Food Science Journal of Ghana Vol. 5 December 2006: 381-39

Seed-borne Mycoflora of major food crops in Ghana

Seed-borne fungi of 152 seed samples of sorghum, pearl millet, rice, maize, groundnut, cowpea, okra, pepper, watermelon, tomato and garden eggs were assessed for fungal infection using the blotter method. Twenty genera and 32 species of fungi were recorded from the seed samples. One hundred and three sorghum samples examined were infected by 24 fungi of which Phoma sorghina (43.3%) and Fusarium moniliforme (40.3%) were the largest groups of fungi recorded. Twenty pearl millet samples tested were infected by 14 fungi with P. sorghina (30.9%) and F. moniliforme (12.2%) as the most frequently recorded fungi. Seven rice samples examined had eight fungi recorded with low percentage infections of important seed-borne pathogens namely Bipolaris oryzae (0.9%), Microdochium oryzae (0.7%) and Sarocladium oryzae (0.5%). Eight fungal organisms were recorded on three samples of maize with F. moniliforme (32.3%) occurring most frequently. Two samples of groundnut tested were found to be heavily attacked by Aspergillus flavus (50.3%) and A. niger (21.8%). Seven fungi were recorded on two samples of cowpea with F. pallidoroseum recording the highest infection of 30.1%. The fungal load of vegetable seed samples was comparatively low with the exception of Phoma sp. and F. moniliforme that occurred in higher numbers on both tomato and pepper while F. pallidoroseum and F. moniliforme occurred in appreciable levels on okra. The least occurring fungi were recorded in the text. Journal of Science and Technology Vol.24(2) 2004: 22-3

Performance of cowpea varieties under Striga gesnerioides (Willd.) Vatke infestation using biplot analysis

Published online: 10 October 2017Striga gesnerioides (Willd) Vatke, is a major destructive parasitic weed of cowpea (Vigna unguiculata (L.) Walp.) which causes substantial yield reduction in West and Central Africa. The presence of different virulent races within the parasite population contributes to significant genotype × environment interaction, and complicates breeding for durable resistance to Striga. A 3-year study was conducted at three locations in the dry savanna agro-ecology of Nigeria, where Striga gesnerioides is endemic. The primary objective of the study was to identify cowpea genotypes with high yield under Striga infestation and yield stability across test environments and to access suitability of the test environment. Data collected on grain yield and yield components were subjected to analysis of variance (ANOVA). Means from ANOVA were subjected to the genotype main effect plus genotype × environment (GGE) biplot analysis to examine the multi-environment trial data and rank genotypes according to the environments. Genotypes, environment, and genotypes × environment interaction mean squares were significant for grain yield and yield components, and number of emerged Striga plants. The environment accounted for 35.01%, whereas the genotype × environment interaction accounted for 9.10% of the variation in grain yield. The GGE biplot identified UAM09 1046-6-1 (V7), and UAM09 1046-6-2 (V8), as ideal genotypes suggesting that these genotypes performed relatively well in all study environments and could be regarded as adapted to a wide range of locations. Tilla was the most repeatable and ideal location for selecting widely adapted genotypes for resistance to S. gesnerioides