THE EFFECT OF VESICULAR‐ARBUSCULAR MYCORRHIZAL ASSOCIATIONS ON GROWTH OF CEREALS

Summary The subsequent growth of maize seedlings which were already mycorrhizal when planted in the field was improved compared with non‐mycorrhizal controls. Mycorrhizal plants removed more phosphorus from the soil and had greater dry matter and phosphorus. There were positive correlations between spore number in the soil and mycorrhizal development, and between extent of root infection and increased growth. Root infection decreased with an increase in phosphorus level of the soil. The onset of the reproductive process in non‐mycorrhizal plants growing without added fertilizer was delayed and, even in those cases where ears did form, their quality was poor. Number of grains per ear and grain weight were increased almost twelve times by the fungus.