Factors Affecting Penicillium oxalicum as a Seed Protectant Against Seedling Blight of Pea

Abstract

Effectiveness of P. oxalicum as a pea seed treatment was improved significantly by: using spores harvested from a Czapek-Dox or a potato-dextrose agar medium and to a lesser extent from an oat grain medium; applying at least 3 .times. 106 and preferably 6 .times. 106 spores/seed; and storing organism-coated seeds for 2 mo. at 5.degree. C instead of 24.degree. C prior to planting. Spores 20-125 days old were equally effective when applied as inoculum for seed treatment. P. oxalicum was not deleterious to pea germination or otherwise pathogenic to peas. P. oxalicum it was more effective in controlling preemergence than postemergence damping-off [caused by fungi].