Effect of canker size on availability of cassava planting materials in Nigeria

Abstract

Cassava (Manihot esculenta L.) production is highly limited by cassava anthracnose disease (CAD) which causes significant losses in planting materials. An experiment was laid out at Ihiagwa, Owern in Nigeria with eighteen treatments replicated three times. Disease severity was scored on a scale of 1-5, and disease incidence was recorded as the percentage of infected plants in each host plant line. In all the three trials, TMS 30211 (425 mm) had cankers high up on the stem, showing that they were infected later in life. This will lead to more disease -free stems. Cultivars Akwakwuru (39.6 mm 2 ), TMS 30555 (31.6 mm 2 ), and Nwaocha (43.7 mm 2 ), had the large canker size on whole plant, young stem, shoot and maturing stem. These cultivars had low resistance to anthracnose. In all the trials, TMS 4(2)1425, and TMS 30211, had the smallest canker size (1.80 and 6.3 mm 2 , respectively) on whole plant, young stems, shoots and maturing stems. TMS 4(2)1425 and TMS 30211 had higher resistance to anthracnose and can be recommended for further improvement through breeding, because plants producing smaller -size lesions survive much longer and would also mature and produce flowers needed for breeding for improving resistance to CAD and other diseases.Key Words: Cassava anthracnose disease, Manihot esculenta, resistance RÉSUMÉ La production de manioc (Manihot esculenta L.) est fortement limitée par la maladie d'anthracnose de manioc (DAO) qui cause des pertes significatives en matières végétales. Une expérience a été présentée avec dix-huit traitements repliés trois fois. La sévérité de la maladie a été marquée sur une échelle de 1-5, et l'incidence de la maladie a été enregistrée comme pourcentage des usines infectées dans chaque ligne d'usine de centre serveur. Dans toutes trois épreuves, TMS 30211 (425 millimètres) a eu des cankers haut vers le haut sur la tige, prouvant qu'ils ont été infectés plus tard dans la vie. Ceci mènera à plus de maladie -tiges libres. Cultivars Akwakwuru, (39.6 millimètres 2

Survey of fungi associated with cassava root rot from different producing regions in Brazil

“…Generally, this is a problem in soils with drainage problems, causing yellowing and leaves with decay accompanied by a bad odor (Seifert, 1985). Another synonym of C. repens is Sphaerostilbe repens, which has also been observed in African countries causing CRRD (Obilo and Ikotun, 2008).…”