Effect of peat-bran inoculum ofTrichoderma species on biological control ofRhizoctonia solani in lettuce
- Cite this article as:
- Maplestone, P.A., Whipps, J.M. & Lynch, J.M. Plant Soil (1991) 136: 257. doi:10.1007/BF02150057
A range of known biocontrol or plant growth-stimulating species ofTrichoderma orGliocladium were grown on peat-bran substrate to yield between 5×107−3×1010 colony forming units (cfu's)g−1 substrate after 14 days growth. Inocula were incorporated into peat:sand potting compost infested withRhizoctonia solani to give 7–8 × 104 cfu's of antagonist g−1 compost and assessed for biological control activity using lettuce seedlings. Six of the eight antagonists decreased daming-off and three of these consistently increased yield in comparison withR. solani treatment alone.
Subsequently, peat-bran inoculum ofT. harzianum isolate TH1 was incorporated at 0.5% w/v intoR. solani infested potting compost. Both autoclaved and nonautoclaved inoculum ofT. harzianum TH1 decreased disease and increased yield. Incorporation of ethyl acetate-extracted autoclaved inoculum ofT. harzianum TH1 resulted in similar levels of biocontrol and improved plant growth as did incorporation of nonautoclaved and autoclavedT. harzianum TH1 inoculum. The need to standardize inocula and controls is emphasized.