Kazeem S.A.,Nigeria Agricultural Quarantine Service |
Kazeem S.A.,University of Ibadan |
Ikotun B.,University of Ibadan |
Awosusi O.O.,Nigeria Agricultural Quarantine Service |
And 2 more authors.
Tropical Plant Pathology | Year: 2015
Leifsonia xyli subsp. xyli (Lxx), the causal agent of ratoon stunting disease of sugarcane (RSD), is a major constraint to sugarcane production worldwide. In Nigeria, the presence of RSD has not been conclusively determined. This study investigated the presence or absence of RSD through surveys in 18 sugarcane growing states in Nigeria. Sugarcane plants or ratoon crops of 7–12 months of age were randomly sampled, and a total of 1190 samples of sugarcane stem cuttings from 76 cultivars were collected. The lowest four internodes were cut longitudinally into nodes, and examined internally for reddish comma-like discoloration. PCR was conducted on DNA extracted from sugarcane sap using Lxx-specific primers. Reddish comma-like internal symptoms of RSD were observed only in samples of cultivar Co510. None of the sugarcane samples, including those from Co510, yielded the 438 bp band expected for PCR detection of Lxx. Immunofluorescence microscopy analyses performed at SASRI, South Africa, using sap from the collected sugarcane samples, also did not detect the bacterium. Thus, the presence of RSD of sugarcane in Nigeria was not confirmed, contrary to its reported presence in 1956. Strict quarantine procedures should be followed to prevent introduction of the pathogen into Nigeria. © 2015, Sociedade Brasileira de Fitopatologia.
Onyeani C.A.,Nigeria Agricultural Quarantine Service |
Osunlaja S.O.,University of Nigeria |
Owuru O.O.,Olabisi Onabanjo University |
Sosanya O.S.,Olabisi Onabanjo University
Asian Journal of Agricultural Research | Year: 2012
This study investigated the etiology of mango fruit anthracnose, its effect on yield and market values in humid Southern Nigeria. The result of the investigation revealed that 96 out of 231 fungal isolates recovered from symptomatic mango parts were Colletotrichum gloeosporioides based on their whitish orange colony, hyaline; single-celled and cylindrical appearance and pathogenicity test. In addition, 60% of mango trees surveyed were infected with anthracnose and over 34% of fruits produced on those trees were found severely infected. Trees treated with fungicide during fruiting retained mean fruit of 57.65 (38.41% above mean in control) while untreated trees retained least mean fruits of 18.35 (55.94% lower than mean in control). A significant reduction in the price of mango was found associated with anthracnose-infected fruits. From the result of the investigation, it was evident that Colletotrichum gloeosporioides was responsible for anthracnose disease in mango and was prevalent in all the study areas. Furthermore, the result revealed that the disease was the cause of mango yield loss and of rendering marketable fruits worthless in Southwestern, Nigeria. © 2012 Knowledgia Review, Malaysia.