Suchergebnisse

Systemwide Program on Integrated Pest Management ; Government of Norway ; Government of Switzerland ; Government of Italy ; Peer Review

Plant parasitic nematode infection of crops can be highly detrimental to agricultural production. Since the discovery that plant roots release chemicals that attract the infective stage of plant parasitic nematodes some 80 years ago, significant progress in identifying the signaling molecules has occurred only relatively recently. Here, we review the literature on chemical ecological studies of two major plant parasitic nematode groups: root knot nematodes in the genus Meloidogyne and cyst nematodes in the genus Globodera because of the negative impact their parasitism has on farming systems in Africa. We then highlight perspectives for future directions for their management. ; Swedish International Development Cooperation Agency ; Department for International Development, United Kingdom ; Swiss Agency for Development and Cooperation ; Austrian Development Agency ; Government of Kenya ; Peer Review

This paper explores the results of a programme designed to facilitate entrepreneurship centred on healthy seed yam (Dioscorea rotundata) production on the eastern bank of the River Niger. Ware yam farmers residing along the eastern bank, upstream of the Niger/Benue confluence, source their planting material from towns such as Ilushi in Edo state, which involves significant travel and expense. The project encouraged 10 ware yam farmers living in Edeke village (Idah local government, Kogi state) to specialize in healthy seed yam production by employing the adapted yam minisett technique (AYMT). This employs a sett size of around 80–100 g treated with a joint insecticide and fungicide dip. The treated setts are planted directly into the field, not first planted into a nursery as with the yam minisett technique (YMT). The Edeke farmers received a loan from the Diocesan Development Services (DDS) to employ the AYMT to produce healthy seed yams on a significant scale. However, while sales of seed yam by four of the farmers generated a significant and positive gross margin, six farmers opted to plant their seed yams in the subsequent season (2012) to produce ware yams. This paper presents some of the results, and discusses the decisions taken and the dilemmas faced by the farmers in the production of seed and ware yam and the possibility of initiating and developing new markets for seed yam in the Idah area. ; Department for International Development, United Kingdom ; Peer Review

Plant-parasitic nematode incidence, population densities and associated damage were determined from 153 smallholder banana and plantain gardens in Bas Congo (9 – 646 meters above sea level, m.a.s.l) and South Kivu (1043 – 2005 m.a.s.l), Democratic Republic of Congo, during 2010. Based on the frequency of total nematode soil and root extraction, Helicotylenchus multicinctus (89%), Meloidogyne spp. (54%) and Radopholus similis (30%) were the most widespread, while Pratylenchus goodeyi (18%) Helicotylenchus dihystera (18%), Rotylenchulus reniformis (14%), and Pratylenchus spp. (6%) were localized in occurrence. The occurrence and abundance of the nematode species was influenced by altitude: R. similis declined at elevations above 1300 m; P. goodeyi declined at elevations below 1200 m; H. multicinctus and Meloidogyne spp. were found everywhere with higher but non-dominant densities at lower altitudes; Pratylenchus spp. was restricted to lower altitudes; while H. dihystera and R. reniformis were scattered at both low and high altitudes. Helicotylenchus multicinctus occurred in higher population densities than other nematode species, especially at the lower elevations. Damage to banana roots (percentage necrotic root tissue) was moderate to high, irrespective of altitude and banana type. To facilitate development of pragmatic plant parasitic nematode management, such baseline studies provide information upon which to enable informed and suitable strategies, such as cultivar selection and distribution. ; Food and Agriculture Organization of the United Nations ; Peer Review

Many genera and species of nematodes attack almost all crops affecting their yield potential. Their distribution, diversity and potential damage depend on many factors including their centres of origin and subsequent spread, the agroecological conditions and the tolerance and resistance of the crops used in that agricultural system. A sustainable approach to the control of plant-parasitic nematodes is to prevent their spread on to clean land. Phytosanitary measures are a major strategy to achieve this aim, and their implementation is part of the regulatory system of each country. A history and description of international plant health legislation is given by Hockland et al. (2006). The interception or detection of listed or unlisted quarantine organisms could result in destruction of a shipment or infected crop, or a banning of growing host plants on infested land. In other cases, suppression of the infestation is considered to be a more practical approach that allows trade to continue. The key nematodes on major world food commodities and their production are discussed in this chapter in addition to the challenges posed by two groups of quarantine nematodes. This information should provide an insight to the problems or potential future problems and the currently known ways to address these.

The distribution of contaminated planting material (suckers) remains a major cause of spread of pests and diseases in banana. A traditional subsistence staple in East Africa, banana is becoming increasingly a commercialized commodity in the region. Essential for effective commercialization of this crop, however, is the supply and use of uniform and healthy planting material. Tissue culture (TC) technology can help provide this. However, TC plantlets are delicate and require substantially greater care and handling than conventional sucker planting material. To distribute TC seedlings to farmers and improve their robustness for successful use on farms, numerous hardening nurseries have been established by TC producers in Kenya, Uganda and Burundi. These nurseries are pivotal in the dissemination of plantlets. In 2008, financing, handling, hardening and marketing of TC-derived planting material through nurseries was assessed using semi-quantitative interviews of nursery operators. The nurseries in Kenya and Uganda are mostly farmer-led and obtain their material from the producer. In Burundi, the nurseries are owned and centrally managed by the producer, while daily activities are handled by technicians. In each country, water supply was identified as a key limiting factor, as the young plantlets desiccate easily. In farmer-led nurseries, plantlet transport and phytosanitary measures, such as soil sterilization and plant protection, are often limited, which can lead to significant plant losses. Governmental and non-governmental institutions purchase large fractions of the TC planting material. Public extension services for TC nurseries were evaluated as poor, leaving the TC producers as the single source of information for nursery operators. Additionally, plantlets tend to be viewed as relatively expensive, while supply is currently sub-optimal, compared to traditional planting material, resulting in a relatively limited and exclusive market. TC planting material in the region is therefore yet to be become sufficiently available for most banana farmers. ; Peer Review