Evaluates how soil phosphorus levels affect mycorrhizal colonization and performance of commercial inoculants in onion seedlings.
This study evaluated the effectiveness of four commercial arbuscular mycorrhizal fungi (AMF) inoculants on onion seedlings under varying soil phosphorus (P) levels. Growth chamber trials tested AMF colonization, plant growth, and nutrient uptake across low, medium, and high soil P conditions using a randomized complete block design. Results showed that AMF colonization occurred primarily in low P soils and declined as soil P increased. Among inoculants, Mykos Gold Granular consistently produced the highest colonization rates. However, increased colonization did not translate into improved plant growth, biomass, or nutrient acquisition in either trial. Onion growth was instead more strongly influenced by soil phosphorus levels, with greater biomass and leaf length observed in medium and high P soils. Findings suggest that while some commercial inoculants can enhance AMF colonization under low P conditions, these effects may not result in agronomic benefits, particularly in soils with sufficient phosphorus.
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Authors
du Toit, L. J., Derie, M., Holmes, B., Morgan, P., Brouwer, B., and Waters, T. D.
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Year Published
2019
Area of Focus
Agricultural Practices
Topics
Crops and Soils & Fertility
Collaborators
- Washington State University Mount Vernon Northwestern Washington Research & Extension Center
