Preponderance and distribution of plantparasitic nematodes in Nassarawa State, North Central Nigeria: consequences for healthy tuber production and export

One of the most cosmopolitan pests responsible for considerable negative economic impacts on yam is the plant-parasitic nematodes. They are also capable of facilitating fungal, bacterial and viral infections of yams. In order to produce healthy yam seeds to meet local demand and tubers for export, there is a need to identify nematode-free areas in Nassarawa, one of the hubs of yam production in Nigeria. To this end, 30 major yam growing communities of the state were surveyed to identify nematode-free areas. Structured questionnaires were administered to three farmers in each of the 10 local government areas selected. Results showed that 97% of the study areas investigated was seriously infested with the three key genera of plant-parasitic nematodes namely Scutellonema, Pratylenchus and Meloidogyne. Incidence and severity of tuber deterioration in transit threatened acceptability of the tubers when it eventually reached England. Healthy yams would attract more income than damaged ones

Variability of host damage and response of some cowpea breeding lines to root-knot nematodes, Meloidogyne spp.

Field and screen house studies were conducted at the International Institute of Tropical Agriculture (IITA) Research Farms, Minjibir, Kano State and farmer’s plot, Ringim, Jigawa State in Sudan Savannah Agro-ecological Zone, North-Western, Nigeria to investigate the reaction of ten cowpea breeding lines to infestation of Meloidogyne spp. Seven-day old seedlings were inoculated with 0 or 5000 eggs of Meloidogyne spp. The experiment was a 2 x 10 factorial, fitted into Randomized Complete Block Design laid out in the fields while the screen house trial laid in Completely Randomized Design. In each location, treatments were replicated four times. Data were collected on plant height, stem girth, root galls, number of days 50% to flowering, pods/plant and seeds/pod. Data obtained were subjected to Analysis of Variance. Statistically variable treatment means were separated using standard error of means at 5% level of probability. Results showed that Meloidogyne spp. induced stunting which results in poor growth and in severe cases affects the time of maturity on susceptible cowpea plants. Hence, highly nematode infested soil should be treated before sowing in order to ensure high qualitative harvest.Keywords: Cowpea, Meloidogyne spp., plant height, stem girt

Evaluation of organic materials for inhibition of nematode reproduction in soybean

Synthetic pesticides have been found to increase the yield of agricultural products over tenfold. However, the effects of pesticide misuse around the world include costly environmental pollution and disruption of the balance of nature in addition to their high cost and non-availability. Hence the need for search for alternative pesticide formulations to avert these undesirable effects. A study was conducted to evaluate the efficacy of Neem ( Azadirachta indica A. Juss) leaf powder and organic fertiliser for management of M. incognita in soybean ( Glycine max ) production. A screenhouse experiment was conducted to test the efficacy of neem leaf powder (NLP) and organic based fertiliser (OBF), alone and a combination of 50% each of the NLP and OBF against root galling and Meloidogyne incognita multiplication on soybean and their potency in grain yield improvement. The experiment was laid out in completely randomised design with three replications. Although all treatments were effective in reducing root galling and nematode reproduction, NLP applied alone gave the highest reduction (92.59 %) in gall formation and nematode multiplication (82.07 %), followed by NLP + OBF and then OBF alone. Increases in grain yield ranged from 103.08 to 108.46% in response to organic soil amendment. Integration of the two organic substances is a better and more promising strategy since it reduced the quantity of organic fertiliser that had to be transported to farmer's field by 50%.Il a été révélé que les pesticides synthétiques augmentent le rendement des produits agricoles au delà de dix fois ; malgré les effets de l'utilisation abusive de pesticides dans le monde entier, y compris la pollution environnementale et la perturbation de l'équilibre de la nature en plus de leur coût élevé et la non-disponibilité. D'où la nécessité de formulations pesticides de remplacement pour éviter ces effets indésirables. Une étude avait été menée afin d'évaluer l'efficacité de la poudre de feuilles de Neem ( Azadirachta indica A. Juss) et des engrais organiques dans la gestion de M. incognita dans la production de soja ( Glycine max ). Deux expérimentations en serre avaient été menées afin de tester l'efficacité de la poudre de feuille du neem (NLP) et de l'engrais à base organique (OBF), seul et en combinaison de 50 % pour chacun de NLP et OBF contre le galle racinaire et la multiplication de Meloidogyne incognita du soja ainsi que de leur efficacité dans l'amélioration du rendement en grain. L'expériementation avait été conduite dans un dispositif complétement aléatoire avec trois répétitions. Bien que tous les traitements étaient efficaces pour la réduction de la galle racinaire et la reproduction des nématodes, lorsque appliquée NLP seule, avait donné la réduction la plus forte baisse (92.59 %) dans la formation de galle et la multiplication des nématodes (82,07 %), suivie par NLP + OBF, et ensuite OBF seul. L'augmentation dans le rendement en grain varié de 103,08 à 108,46 % en réponse à l'amendement organique du sol. L'intégration de ces deux substances organiques est la meuilleure et la plus prometteuse stratégie car il réduit de 50 % la quantité d'engrais organiques qui doit être transportés au champ de l'agriculteur

Occurrence and prevalence of nematodes in yam fields from four community-based farming scheme locations in Ogun State, Nigeria

Nematodes is one of the major biotic constraints affecting profitable yam production throughout Nigeria. They affect yams both in the field and in storage thus threatening food security and economic deprivation to growers and their households. The research work identified the types, frequency and population of nematodes associated with Dioscorea rotundata grown by the Farm Practical Year Programme Trainees of the Federal University of Agriculture, Abeokuta in four Community-based Farming Scheme locations, namely Isaga-Orile, Iwoye-Ketu, Ode-Lemo and Odogbolu in Ogun State. Soil samples were taken and assayed for nematode populations. Results showed that 26 Nematodes genera were found in the four locations ranging from 11 to 3201 individuals/250 g soil. Genera of plant-parasitic nematodes recovered included Scutellonema, Meloidogyne, Pratylenchus, Paratylenchulus, Trichodorus, Helicotylenchus, Hoplolaimus, Tylenchorhynchus, Aphelenchus, Xiphinema, Ditylenchus, Rotylenchulus, Rotylenchus and Aphelenchoides while the free-living nematode genera found included Aulolaimoides, Cephalobus, Cylindrocorpus, Lotonchus, Monhystera, Oncholaimus, Paraplectonema, Prismatolaimus, Dorylaimus, Tylencholaimellus, Tylencholaimus, and Tyleptus. Out of the twenty-six nematodes encountered, Meloidogyne spp. Scutellonema spp. and Pratylenchus spp. were mostly encountered in the soil and the only three recovered from the tubers which mean that these three nematodes are of economic importance to yam production. Farmers are therefore advised to go into yam production with management measure of nematodes putting the three key nematodes in mind, in order to avoid yield loss.Keywords: White guinea yam; Meloidogyne spp.; Scutellonema spp.; Pratylenchus spp