BBTD containment by phytosanitation of infected plants in Cameroon

Banana and plantain (Musa spp.) contribute to livelihood and income in Central Africa, they are amongst,the most important food crops. BBTDwere first reported in Cameroon in 2009, Under the BBTV Alliance for banana bunchy top disease control in Africa, works were done on (1) characterization of banana farming system in BBTD affected area, (2) assessment of disease effect on farm, (3) Evaluation of the reduction in BBTD incidence after rouging and subsequent follow up visits (4) assessment of the effect of farming system on phytosanitation of BBTV infected mats and implication on BBTD management in smallholder farms in three locations in BBTD endemic area of South Cameroon.This work showed that, three sources of seeds; existing fields, buying from neighbor fields or village, and Extension service were identified with existing field as the main source of plantain seeds without any insurance of phytosanitary quality. The most frequent or popular varieties are AAB plantains Ebang, Essong and Elat, all susceptible to BBTD. Three type of farms were identified during this work; household, fallow and forest farms. BBTD incidence is greater in Mengama than Abang Minko’o and Nlono; The reinfection rate was progressively slow down with the increase of number of follow-up visit, while the lowest reinfection rate was obtained in the forest farms in low BBTD pressure area. In general, phytosanitation has contributed to reduce BBTD incidence in all the three locations and types of fields. Reduction in BBTD incidence achieved but 100% reduction was limited to fewer fields Reduction in BBTD incidence easily achieved in low disease pressure area. Frequent follow-up visits are needed for phytosanitation to be effective for BBTD control in Cameroon.香蕉与芭蕉（Musa spp.）是中非地区保障民生、增加收入的核心粮食作物之一。香蕉束顶病（BBTD, Banana Bunchy Top Disease）于2009年首次在喀麦隆被报道。在非洲香蕉束顶病毒（BBTV, Banana Bunchy Top Virus）防控联盟框架下，研究团队针对喀麦隆南部BBTD流行病区的三个点位开展了如下研究工作：(1) 解析受BBTD侵染区域的香蕉种植系统特征；(2) 评估病害对农场生产的影响；(3) 评价拔除染病植株并开展后续跟踪回访后，BBTD发病率的变化情况；(4) 探究种植系统对感染BBTV的蕉丛的植物卫生防控措施的影响，以及该措施对喀麦隆南部BBTD流行病区内小农户农场BBTD管理的借鉴意义。 本研究明确了芭蕉种苗的三大来源：现有种植田自留种苗、向邻田或村内农户购种、以及农业推广服务供种，其中以现有种植田自留种苗为最主要的种苗来源，但该来源未附带任何植物卫生质量保障。 当地种植最广泛、认可度最高的芭蕉品种为AAB基因组型的Ebang、Essong与Elat，所有品种均对BBTD易感。 本研究共识别出三类农场类型：家庭农场、休耕农场与林下农场。Mengama点位的BBTD发病率高于Abang Minko’o与Nlono点位；随着跟踪回访次数的增加，再侵染率逐步降低；而在BBTD压力较低的区域，林下农场的再侵染率最低。 总体而言，植物卫生防控措施可有效降低三个点位与各类农场的BBTD发病率。虽可实现BBTD发病率的下降，但仅在少量农场中实现了100%的病害防控效果。在病害压力较低的区域，BBTD发病率的下降更易实现。在喀麦隆开展BBTD防控时，需通过高频次的跟踪回访，才能保障植物卫生防控措施的实施效果。