Description:
<p>Lignosulphonates, low cost by-products of the pulping process, have shown suppressive effects against some diseases caused by soil-borne pathogens. In this study, the effect of 1.5% v/v calcium lignosulphonate (Ca-Ls) amendment to two commercial potting mixes (peat + coconut fibres; PC; and municipal compost + peat + pumice; MCPP) on the viability of <italic>Sclerotinia sclerotiorum</italic> sclerotia was investigated. Sclerotia were buried in the Ca-Ls amended substrates for 30 days. Non-amended PC and MCPP, sterile sand and sterile PC with and without Ca-Ls were used as controls. The viability of sclerotia recovered from PC and MCPP amended with Ca-Ls was reduced by 50 and 42% respectively compared to control treatments. Ca-Ls amendment decreased sclerotial viability by enhancing the activity of the indigenous mycoparasitic fungi, <italic>Fusarium oxysporum, Mucor</italic> spp. and <italic>Trichoderma</italic> spp. The biocontrol ability of Ca-Ls against sclerotia was due to the stimulation of microbial activity and is, therefore, strictly dependent on the microbial composition of the substrate.</p>