Fundam. appl. Nemawl., 1998,21 (6), 645-654 Plant parasitic nematodes associated with crops grown by smallholders in Mozambique Rinie VAN DEN OEVER*, Esther VAN DEN BERC** and Jorge A. CHIRRUCO*** *19lcAnh GiacStr., My Tho, Tien GiangProv., Vietnam, "National Collection ofNematodes, Biosysternatics Division, Plant Protection Research Institute, Private Bag X134, Pretoria 0001, South Ajrica, and '***Plant Protection Department (DSV), cio INIA, CP 3658, Maputo, Mozambique Accepted for publication 15 Decernber 1997. Summary - Crop surveys in Mozambique during 1992-1996 revealed the presence and the large distribution of several plant­ parasitic nematodes. Root-knot (Meloidogyne spp.) and lesion (Pralylenchus spp.) nemarodes are the predominant and most widespread forms. Severa1 nematode species were found for the first time in Mozambique, whereas others were found on diffe­ rent crops than in previous surveys. Pralylenchus zeae was found frequently on maize, and also on common bean (Phaseolus vulgaris L.), sugarcane, and sunflower. Root-knot nemarodes were serious pests of common bean, when the beans were grown rogether with maize in Niassa province, and also of cowpea in experimental fields and irrigation areas in the south, sunflower in Niassa province, robacco in Nampula and Manica provinces, and vegetables from several areas. Roet-knot nemarode was not found ro be a problem on cassava in Mozambique. The peanut pod nemarode Dilylenchus afmanus was found in Maputo and Gaza provinces and may have been inrroduced with imponed groundnut used for seed or human consumption. © Orsrom! Elsevier, Paris Résumé - Nbnatodes phytoparasites associés aux cultures paysannes du Mozatnbique - Des enquêtes effectuées sur les cultures du Mozambique de 1992 à 1996 ont révélé la présence et l'imponance de nombreux nématodes phytoparasites, MeloiiÙJgyne spp. et Pracylenchus spp. étant les plus répandus et prédominants. Plusieurs espèces ont été trouvées pour la première fois au Mozambique, tandis que d'autres ètaient relevées sur d'autres plantes que celles signalées lors des enquêtes précédentes. Pralylenchus zeae est fréquent sur le maïs, mais aussi sur le haricot (Phaseolus vulgaris L.), la canne à sucre et le rournesol. Meloidogyne spp. sont de sérieux ennemis du haricot commun lorsqu'il est interp1anté avec le maïs dans la province de Niassa, et également du niébé dans les champs expérimentaux et les zones irriguées du sud, du tournesol dans la province du Niassa, du tabac dans les provinces de Nampula et Manica, et enfin des plantes maraîchères en de nombreuses localités. Mais au Mozambique ces némarodes ne constituent pas un problème pour le manioc. Dùylenchus africanus, qui attaque les gousses d'arachide, a été trouvé dans les provinces de Mapuro et Gaza et pourrait y avoir été introduit lors de ['imponation d'arachides utilisées comme semences ou pour la consommation humaine. © OrstomlElsevier, Paris Keywords: crops, Mozambique, plant parasitic nemarodes, survey. Since 1968, nemarological research in Mozambique Maputo and Gaza, because of safety problems (Van has focused on commercial crops such as banana den Oever & Mangane, 1992). (Lima & Reis, 1969), sugarcane (Reis, 1974), and cit­ As little was known about the importance and dis­ rus (Reis, 1982). After independence in 1975, atten­ tribution of nematodes in the rest of the country, tion was given mainly to agricultural production on especially on food crops, several surveys were carried state farms and co-operatives, where food and cash out in smallholders fields during 1992-1996 to obtain crops are grown in a monoculture system. In 1983, it additional information on the incidence of nematodes was decided that smallholders shou1d get more atten­ on the most important crops throughout Mozam­ tion in order to improve the production of food crops bique. in their mixed farming systems. Maize is the predomi­ nant staple crop in most provinces, and cassava in Materials and methods sorne provinces. Cowpea is the most widely grown legume intercrop, followed by groundnut, whereas SURVEYS common beans are favoured in sorne areas at higher A summary of the most important surveys carried altitude. out during the study period is presented in Table 1. During 1984-1990, various crops were sampled for Food crops in Niassa province, mainly common the presence of nematodes, but the areas visited were beans, were sampled to establish whether the root­ restricted to parts of the southem provinces of knot nematode problem, observed in sorne bean Fundam. appl. Nemawl. 1164-5571/98/06/ © OrslOmlElsevier, Paris 645 R. van den Oever et al. Table 1. Areas and cmps sampled during Ihe surveys carried out in smallholders fields in 1992-1996. Province Period Main crops sampled No of samp1es Type of sampie (districts) Niassa May 92 cornmon bean 7 ri + s2 (32)3 banana 7 l' + S pumpkin 4 l' + S Niassa March 93 common bean 6 s ± l' (32) maize 2 Niassa Febr. 94 common bean 8 l' (32) maize 17 l' Niassa May 95 common bean 38 l' + S (32, 33, 34) sunflower 9 l' + S Maputo Jan. 93 maize 58 (2) cowpea 40 cassava 15 s groundnut 6 s pumpkin 11 s Inhambane June 93 cassava 30 l' + S (Il, 12, 14, 16, 17) 4 Inhambane Dec.93 groundnut 12 l' + S + sh (Il, 12) Gaza Dec.93 groundnut 10 l' + S + sh (9, 10) Gaza Dec.94 groundnut 24 l' + S + sh (7, 9, 10) Maputo March 95 groundnut 21 l' + S + sh (3, 5, 6 ) Nampula April 95 groundnut 14 l' + S + sh (27, 28,30) cowpea 21 l' + S Nampula Aug.l Sept. 94 cassava 27 (+8)5 l' + S (24, 25, 26, cowpea 4 l' 27, 29, 30) pigeon pea 2 l' Nampula Jan. 96 tobacco 27 (+ 5)6 l' (30, 31) maize 5 l' Manica March 96 tobacco 19 (+ 33)7 l' (19,20,21) maize 3 ( + 7) 7 l' J r = roots; 2 s = soil; 3 (.) district number (Fig. 1); 4 sh = groundnut shell; 5 samples were stolen; 6 samples of tobacco company; 7 samples of tobacco companies experiments at the Agricultural Experiment Station in the roots of ten ra fifteen plants pel' field was col­ Lichinga (EAL), also existed in smallholders fields in lected. the area. Maize is cultivated in a mixed cropping sys­ As groundnut is an important legume crop in tem with common bean, with [wo bean crops during Mozambique, it was decided ra sample sorne produc­ one maize crop. For the survey, roots and soil of ten ra tion areas in the south and the north to establish fifteen plants pel' field were collected. whether nemarades were as much a problem there as Maize, cowpea, cassava, groundnut, and pumpkin they are in the neighbouring country of South Africa. grown by smallholders in the Gueguegue, Umpala, Smallholders fields were visited at harvest rime. Massaca l, and Radio Marconi areas in Boane district Twenty plants pel' field were uprooted, roots and pods were sampled during a survey on pests and diseases collected for nemarade extraction, and the seed carried out by the Plant Production and Protection source was established. Departmenr of the Faculty of Agronomy of the Edu­ In 1992, cassava tubers from an introduced cultivar ardo Mondlane University in early 1993. Soil around in an experiment at the Agricultural Experiment Sta- 646 Fundam. appl. Nemalol. Nematodes in smallholders cropsin Mozambique tion of Umbelùzi (AEU) in Maputo province were rite method of Hussey and Barker (1973) and the brought in by the staff of the National Agricultural method of Stemerding (1963). The former method Research Institute (INIA). They were heavily dis­ was used for ail tobacco roots collected during 1996. torted and infested by root-knot nematodes. There­ Nematodes were extracted from 100 ml of soil by fore, sorne cassava varietal field experiments were Cobb's modified decanting and sieving method sampled at harvest time at AEU (1992, 1993) and (s'Jacob & Van Bezooyen, 1984). Nhacoongo Agricultural Experiment Station (NAES) Nematodes were killed with hot formalin-propionic in Inhambane province (1995). A survey was also acid (FP4: 1), processed using Seinhorst's (1959) done in smallholders fields in Inhambane and Namp­ rapid glycerol-ethanol method, and mounted in pure ula provinces where cassava is a major crop. Tubers anhydrous glycerol. and roots of five to ten plants per field were examined Perineal patterns of Meloidogyne spp. were cleaned and roots and soil collected for extraction. in lactic acid 45% and mounted in pure anhydrous Heavy root-knot nematode infestation was fre­ glycerol (Taylor & Netscher, 1974). quently observed in cowpea in the south and in sorne Most nematodes were identified by the taxonomists places in Nampula province during the cassava survey of the Biosystematics Division of the Plant Protection of 1994. Consequently, cowpea was surveyed during Research Institute in Pretoria, South Africa, and sorne the groundnur survey in Nampula province in April at the International Institute of Parasitology in St. 1995. In each field, roots and soil were collected from Albans, UK. ten plants of the second cycle crop. During the groundnut-cowpea survey in Nampula Results province in 1995, sorne tobacco plants heavily Fig. 1 shows the sampling localities. Table 2 lists the infested with root-knot nematode were found in rwo nematodes found associated with various crops. The fields where cowpea did not show any sign of infesta­ districts of origin of the species identified are indi­ tion. As tobacco cultivation had recently increased cated by numbers berween brackets. These numbers again in Nampula and Manica provinces, where it had correspond to the numbers in Fig. 1. Twenty-six nema­ been intensively cultivated in the past, a survey was tode species and one genus are new records for carried out. In the Ribaue and Malema districts, both Mozambique. in Nampula province, mainly smaliholders fields were visited. These farmers are supported by a private MAIZE enterprise which sells the seed to them and buys their One hundred and eleven sampies were collected in harvest.
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