Vesicular–arbuscular endomycorrhizal inoculum production. I. Exploratory experiments with beans (Phaseolus vulgaris) in nutrient flow culture

A system is described in which typical vesicular–arbuscular (VA) mycorrhizal infections were produced in bean plants (Phaseolus vulgaris) grown in trays in which the roots were bathed in a shallow layer of recirculating nutrient solution (nutrient film technique, NFT). Infections were compared in solutions containing 1, 3, and 8 mg∙L−1 P, bonemeal, and rock phosphate. The infectivity of the NFT-grown mycorrhizal roots was tested using 1.2, 0.24, and 0.05 g of fresh root inoculum on maize and bean seedlings. The inoculum had good infectivity and even 0.05 g produced 5–10% infection in test seedlings after 6 weeks.