Response of meloidogyne hapla to mycorrhiza fungi inoculation on pyrethrum

Five arbuscular mycorrhiza fungi (AMF) isolated from pyrethrum were screened in the greenhouse for efficacy in improving pyrethrum growth and in suppressing a root-knot nematode, Meloidogyne hapla. The fungi screened were Glomus spp. (isolates LM61, ML34 and ML35), Scutellospora sp. (isolate KS74) and Gigaspora sp. (isolate LM83). A 20g mixed fungal inoculum was incorporated into sterilized sand-soil mixture before transplanting 6-week-old pyrethrum seedlings. The inoculum consisted of the growth medium, spores, external mycelia and infected rootsegments. The plants were inoculated with 6000 M. hapla second stage juvenile (J-2) 3 months after fungal inoculation. Dry shoot weights, fresh root weights, percent root colonization by the fungi, nematode gall indices, number of eggs and females in the root system and number of J-2 in the soil were determined at the end of the experiment, two months after nematode inoculation. Glomus LM61 and Scutellospora KS74 significantly improved top biomasses of fungus-treated and fungus-nematodetreatedplants. Glomus LM61was more effective (33% top biomass increase). Glomus ML34 and ML35 and Gigaspora LM83 improved top biomasses of fungus-nematode-treated plants. Scutellospora KS74 and Glomus ML34 significantly increased fresh root weights of pyrethrum by 45% and 50%, respectively. Glomus LM61, Scutellospora KS74 and Gigaspora LM83 caused 86%, 32% and 37% nematode suppression, respectively. All the fungal isolates significantly reduced the number of females and J-2. The presence of nematodes in fungus-treated plants did not affect rootcolonization by the fungi except in plants treated with Glomus ML34 and ML35

Use of arbuscular mycorrhiza fungi for improved crop production in sub-Saharan Africa

Soil fertility depletion through crop removal, soil erosion and leaching is a major challenge to increased crop productivity in Sub-Saharan Africa. Whereas nitrogen can be replenished using Rhizobium inoculants and growing leguminous crops, P is difficult to replenish. This is due to the high fixing capacity of most soils in Africa and the high cost of inorganic fertilizers. Arbuscular mycorrhiza fungi (AMF), endophytic fungi reputed for their ability to enhance P uptake can be used to alleviate P deficiencies and improve crop productivity. Although the technology has been used in developed countries, it has not been applied in crop production systems in Africa to any significant level. This is due to poor management of indigenous AMF populations, high cost of inoculants and challenges associated with the inoculum production and efficacy. These challenges are discussed in detail in this paper. Possible and practical ways of impacting these challenges are discussed. They include production of inoculum in farmers' fields to reduce transport costs, development of multi-agent inoculants to reduce cost of inoculum and genetic manipulation to improve the quality of the symbionts. Key Words: Arbuscular mycorrhiza fungi, crop production, phosphorus, soil fertility, sub-Saharan Africa Journal of Tropical Microbiology Vol.1(1) 2002: 14-2

Arbuscular Mycorrhizal fungi (AMF) inoculum production for use in horticulture

This paper discusses the feasibility of applying arbuscular mycorrhiza fungi (AMF) technology to horticultural production systems. Horticulture easily lends itself to AM inoculation because most horticultural plants are initially established in nurseries under controlled conditions. The application of AMF can greatly reduce production costs especially when applied together with other beneficial microorganisms such as Rhizobium, Plant Growth Promoting Rhizobacteria (PGPR) and phosphate-solubilizing bacteria or when combined with cheap sources of phosphorus such as Rock phosphate and other biotechnologies such as micropropagation. Arbuscular mycorrhiza fungi and their benefits in horticultural systems are briefly described in this paper. Some examples where AMF have been practically used in horticultural systems and the need to manage indigenous AMF population through sound agricultural practices are also discussed. Artificial inoculation with efficient AM fungi is, however, emphasized because indigenous AMF populations have greatly been reduced by monocultural practices. Furthermore, even when indigenous AMF are present, their efficacy is not guaranteed and hence the need for artificial inoculation. Different inoculum production systems and inoculation procedures are discussed. Finally some of the ways in which the efficacy of AMF inocula can be improved are discussed. Keywords application, arbuscular mycorrhizal fungi, horticulture, inoculum Journal of Tropical Microbiology and Biotechnology Vol. 2(1) 2006: 46-5