Screening of Musa germplasm for resistance and tolerance to nematodes

In most regions of the world, nematodes are recognized as important pests of bananas. Because banana nematodes attack the root and/or corm tissues, plant growth and yield are affected. The objective of these technical guidelines is to stimulate interest in nematode resistance and tolerance screening in bananas, and to provide a methodology for carrying out such screening: plant material, nematode inoculum, screening experiments in pots or in the field, nematode reproduction assessment, and damage assessment INIBAP/CTA (French version available

The burrowing nematode of bananas Radopholus similis

Description of the banana nematode Radopholus similis (ecology, natural distribution, development cycle and pathotypes), the damage and losses that it causes and control methods (cultural, physical, chemical and genetic)

The root lesion nematodes of banana: Pratylenchus coffeae (Zimmermann, 1898) Filip. & Schu. Stek., 1941, Pratylenchus goodeyi Sher & Allen, 1953

Musa pest fact sheet on the root lesion nematodes of banana : Pratylenchus coffeae and Pratylenchus goodeyi. It describes the latest information on the distribution and symptoms of these parasites of Musa and their control and invites collaboration in ongoing research

Evaluation of Musa host plant response using nematode densities and damage indices

Host plant response of seven Musa accessions to Radophlus similis and helicotylenchus multicintus was evaluated at Namulonge, Uganda.Suckers detached from first cycle harvested plants grown in inoculated and not inoculated fields were indexed for root and corm damage. Nematodes were extracted from the indexed roots. Relationship between root damage parameters and nematodes population densities were examined using correlation and principal component analysis. Damage parameters were of major importance. Three groups of cultivars could be statistically differentiated. The cultivars Gros Michel(Musa AAA), Pisang Awak (Musa AAA) and Obino I Ewai (Musa AAB) were more sensitive and susceptible to nematode attack. Cultivar Nabusa (Musa AAA, highland banana clone set Nfuuka) was intermediate and did not differ significantly from either group

Yield loss from plant parasitic nematodes in East African highland banan (Musa spp. AAA)

East African Highland bananas (Musa spp., AAA) also known by their vernacular name ‘matooke', are a major staple food for the densely populated high elevation regions of Eastern and Central Africa. Banana production, however, is declining due to increased pest and disease pressure. Nematodes are considered to be a major constraint. An experiment was established at the East and Southern Africa Regional Centre of the International Institute of Tropical Agriculture at Sendusu (Uganda) to assess the yield loss caused by nematodes to East African Highland banana. Sendusu, at an elevation of 1128 m, is representative of the lower Musa production zones in Uganda. The major nematode species affecting Musa at this elevation are Radopholus similis and Helicotylenchus multicinctus. The production of a plant crop of East African highland banana, established with hot water disinfested planting material, was 51% higher compared to a crop established with nematode infested material. Bunch weight was significantly higher (P < 0.001) in plots planted with disinfested propagules than in those plots planted with nematode infested material. Owing to vigorous growth and lower plant toppling (P < 0.01), more bunches were harvested (P < 0.01) in the non-infested plots compared to the plots established with infested planting material. Root and rhizome damage and R. similis and H. multicinctus density were significantly lower in roots of suckers detached from harvested plants (P < 0.001) established with disinfected material compared to suckers detached from nematode infested material

Plant parasitic nematodes associated with plantain (Musa spp. AAB-group) in southern Nigeria and their relative importance compared to other biotic constraints

Published online: 01 Jan 2001The predominant nematode species found on plantain in southern Nigeria was Helicotylenchus multicinctus which occurred at all 68 sites sampled. Hoplolaimus pararobustus, Pratylenchus coffeae and Radopholus similis were found at 64, 50 and 46% of the sites, respectively, while Meloidogyne spp. second stage juveniles were found at 68% of the sites. Other nematode species occurred at less than 5% of the sites and included Helicotylenchus dihystera, P. zeae, P. brachyurus, Rotylenchulus reniformis, Scutellonema and Criconemoides spp. H. multicinctus and P.coffeae occurred at high densities (on average about 10 500 and 3500 nematodes/100 g fresh root weight, respectively), compared to the other species. P.coffeae was more common in the west and mid-west of southern Nigeria, while R. similis was more common in the east. Factors, derived from a principal component analysis of observations of damage caused by nematodes, the banana weevil Cosmopolites sordidus and the fungus Mycosphaerella fijiensis, the cause of Black Sigatoka, were related to plant growth observations. The results suggest that P.coffeae followed by R. similis are the major biotic constraints of plantain production in southern Nigeria. Higher losses are anticipated by these plant parasitic nematodes than by either M. fijienis or C. sordidus

Evaluation of yam host-plant response to rootknot nematodes in Uganda

A field trial was established at Sendusu. 40 km north of Kampala. Uganda, to evaluate the response of yarn lines, developed by the International Institute of Tropical Agriculture (IITA), to nematode infestation. The field was naturally infested with nematodes and plants were established from tissue culture. Harvested yam tubers were infested mainly with Meloidogyne javanica and, to a lesser extent, with Pralylenchus spp.; Scutonel/onema sp., Rolylenchulus sp. and HelicOlylenchus sp. were round occasionally. Line TOR 87/00559 OP (38) supported the highest population 01 M javanica juveniles, while lines TDR 87/00571 OP {71} and TDR 91/00121 OP {22} did not support any nematode species, suggesting the existence 01 resistance to root•knot nematodes in the IITA germplasm collection

Optimum sample size for Pratylenchus goodeyi (Cobb) Sher and Allen density and damage assessment in highland banana (Musa AAA) in Uganda

The optimum sample size for assessment of nematode densities and related damage in East African highland banana was estimated at Kikoni parish in Ntungamo district, Uganda. Kikoni parish is at an elevation ranging from 1360 to 1480 meters above sea level and the East African highland banana (Musa AAA, Matoke and Mbidde groups) is the dominant crop. The parish is approximately 10 km2 in size, with an estimated total of 500 farms. Out of these farms, 24 were randomly selected and a minimum of 15 plants per farm were sampled. Root samples were collected from recently flowered plants, assessed for root damage and nematodes were extracted from the scored root segments. Hierarchical classification analysis was performed on the values for density and damage to calculate the coefficient of variation and the method of maximum curvature was used to determine the optimum number of farms in the parish and number of banana plants within each farm for nematode density and damage assessment. Pratylenchus goodeyi was the dominant species with densities ranging from 500 to 25,000 per 100g fresh root weight, while the percentage dead roots ranged from 0.8% to 14.0% and the percentage root necrosis from 1.1% to 17.1%. The optimum numbers established, were three farms within the parish and five recently flowered banana plants in each farm

Foliar Diseases of Banana in Uganda: Results from a Diagnostic Survey

Data are presented on the incidence and severity of (black and yellow) sigatoka leaf spots and Cladosporium freckle in different ecological zones of Uganda. Black sigatoka has become widespread since its arrival in Uganda in 1988. Sigatoka leaf spots were most severe in mid-elevation zones of central Uganda. The disease was absent at altitudes above 1500m and in drier zones (3-5 wet months per year). Cladosporium freckle was present at all survey sites and also most severe in central Uganda

Optimum sample size for Pratylenchus goodeyi (Cobb) Sher and Allen density and damage assessment in highland banana (Musa AAA) in Uganda

The optimum sample size for assessment of nematode densities and related damage in East African highland banana was estimated at Kikoni parish in Ntungamo district, Uganda. Kikoni parish is at an elevation ranging from 1360 to 1480 meters above sea level and the East African highland banana (Musa AAA, Matoke and Mbidde groups) is the dominant crop. The parish is approximately 10 km2 in size, with an estimated total of 500 farms. Out of these farms, 24 were randomly selected and a minimum of 15 plants per farm were sampled. Root samples were collected from recently flowered plants, assessed for root damage and nematodes were extracted from the scored root segments. Hierarchical classification analysis was performed on the values for density and damage to calculate the coefficient of variation and the method of maximum curvature was used to determine the optimum number of farms in the parish and number of banana plants within each farm for nematode density and damage assessment. Pratylenchus goodeyi was the dominant species with densities ranging from 500 to 25,000 per 100g fresh root weight, while the percentage dead roots ranged from 0.8% to 14.0% and the percentage root necrosis from 1.1% to 17.1%. The optimum numbers established, were three farms within the parish and five recently flowered banana plants in each farm.La grandeur optimale de l'\ue9chantillon pour \ue9valuer les densit\ue9s des n\ue9matodes et les d\ue9g\ue2ts qui y sont li\ue9s sur les bananes en hautes terres de l'Afrique de l'Est a \ue9t\ue9 estim\ue9e en Uganda dans la localit\ue9 de Kikoni, Ntungamo district, situ\ue9e entre 1360 et 1480 m d'altitude. La culture la plus dominante dans cette localit\ue9 est la banane comprenant les groupes de Musa AAA, Matoke et Mbidde. Kikoni a une grandeur de 10 km2 avec un nombre total d'environs 500 fermes. De ceci, 24 fermes ont \ue9t\ue9 s\ue9lectionn\ue9es au hasard et 15 plants \ue9chantillon\ue9s par ferme. Les \ue9chantillons des racines ont \ue9t\ue9 collectionn\ue9s des plants en floraison, \ue9valu\ue9s pour les d\ue9g\ue2ts sur les racines; et les n\ue9matodes ont \ue9t\ue9 extraits \ue0 partir des fragments des racines \ue9valu\ue9s. L'analyse hi\ue9rarchique de classification a \ue9t\ue9 perform\ue9e sur les valeurs pour la densit\ue9 et les d\ue9g\ue2ts afin de calculer le coefficient de corr\ue9lation. La m\ue9thode de courbure maximale a \ue9t\ue9 utilis\ue9e pour d\ue9terminer le nombre optimum de fermes dans la localit\ue9 et les plants des bananiers dans chaque ferme pour l'evaluation de la densit\ue9 des n\ue9matodes et les d\ue9g\ue2ts. Pratylenchus goodeyi \ue9tait l'esp\ue8ce dominante avec densit\ue9s allant de 500 \ue0 25000 par 100 g de poids frais des racines, pendant que le pourcentage des racines mortes variat de 0.8 \ue0 14.0 % et le pourcentage des racines n\ue9cros\ue9es de 1.1 \ue0 17.1 %. Le nombre optimun \ue9tabli \ue9tait de 3 fermes dans la localit\ue9 et 5 plants de bananiers en floraison dans chaque ferme