Cassava Anthracnose Disease and Varietal Screening for Resistance in Akwa Ibom State of Nigeria

作     者：R. C. Wokocha N. E. Nneke 

作者机构：Department of Plant Health Management Michael Okpara University of Agriculture Umudike P.M.B. 7267 Umuahia Abia State Nigeria Department of Crop Science University of Uyo P.ikL B. 1017 Uyo Alcwa Ibom State Nigeria 

出 版 物：《Journal of Agricultural Science and Technology(B)》 (农业科学与技术（B）)

年 卷 期：2011年第1卷第6期

页      面：889-895页

学科分类：09[农学] 0904[农学-植物保护] 0901[农学-作物学] 090401[农学-植物病理学] 090402[农学-农业昆虫与害虫防治] 

主　　题：Cassava disease cassava anthracnose disease Collectotichum gloeosporioides f. sp. manihotis screening for diseaseresistance disease resistance. 

摘      要：Cassava （Manihot esculenta Crantz） production in Akwa Ibom State is limited by cassava anthracnose disease （CAD） which causes enormous losses in planting materials. Survey of the disease was conducted in the wet and dry seasons in six major cassava-growing areas （Essien Udim, Ikono, Itu, Nsit Atai, Oruk Anam and Uyo） of the State to determine the incidence and severity of the disease. Ten commonly grown cassava varieties were then screened in the greenhouse by inoculating each variety with the spore suspension of virulent isolate of the cassava anthracnose pathogen. Disease severity was assessed using size of lesions on the inoculated plants and defoliation caused by the infection. Results of the survey showed that Nsit Atai is a high infection area for CAD. It recorded the highest disease incidence and severity in both the wet season （36.59% and 3.52） and dry season （9.26% and 2.20）, respectively. The mean disease incidence （24.10%） and severity （3.23） for the six study areas were higher in the wet season indicating the importance of this season in the occurrence of CAD. Results of the screening test showed that TMS 98/30572 was resistant to the disease. The small lesion size （5.00 mm） observed in this variety would ensure less stem disruption and timely delivery of resources to the actively growing points. The low defoliation （5,65%） observed in the same variety would enhance the photosynthetic capacity of the plant. Therefore, TMS 98/30572 may be recommended to cassava farmers in Akwa Ibom State.