Efficacy of biocontrol agents in planting mixes to colonize plant roots and control root diseases of vegetables and citrus

• Published in: Crop protection 1996-12, Vol.15 (8), p.735-742
• Main Authors: Nemec, S., Datnoff, L.E., Strandberg, J.
• Format: Article
• Language: English
• Subjects: Bacillus; Gliocladium; Glomus; Mycorrhiza; Phytophthora parasitica; root rot; Streptomyces; Thielaviopsis basicola; Trichoderma
• ISSN: 0261-2194; 1873-6904
• DOI: 10.1016/S0261-2194(96)00048-8

Tomato, bell pepper, celery and citrus were propagated in planting mixes amended with formulations of commercial biocontrol agents. Root colonization by selected biocontrol agents was evaluated for pepper, tomato and citrus, and found to be generally between 76 to 100% in both greenhouse ebb and flow, and bench-produced plants. Only colonization by Glomus intraradices was low, about 8%. All biological control agents, Trichoderma harzianum, Bacillus subtilis, G. intraradices, Gliocladium virens, and Streptomyces griseovirdis reduced crown rot of tomato in the field, with T. harzianum and B. subtilis being the most effective uniformly among four tests. Four biocontrols reduced Phytophthora root rot on citrus in the field, two applied as a drench to soil in pots reduced Thielaviopsis root rot on citrus, and two biocontrol agents in combination reduced celery root rot caused by Pythium and Fusarium spp., however, none improved above-ground plant growth or health of citrus and celery. Pepper crown and root rot caused by P. capsici was reduced by B. subtilis in one of two tests.