Effects of the particle size of soil-less substrates upon AM fungus inoculum production

Glomus intraradices

was examined in a locally available sand graded by particle size, planted with Zea mays and fertilized with a nutrient solution. Plants in sand with particle sizes of 0.50–0.78 mm had higher root fresh weights, spore production and percent mycorrhizal colonization than with other particle sizes. Production of spores and infectious propagules was enhanced by a nutrient solution without P. Plants were also inoculated with G. intraradices in pots containing clay-brick granules, charcoal, coalmarl, sand or perlite of the optimal particle size (0.50–0.78 mm). Percent root length colonized by G. intraradices and production of infectious propagules were 40–50 % higher for plants grown in clay-brick granules and sand than in the other media.