Inhibition of fungal infection using sulfite pads prior to initiation of callus from Vitis labruscana cv. Concord

Incubation of plant material with potassium metabisulfite was found to inhibit fungal infections of explants from grapevines. Grapevine tissue of Vitis labruscana cv. Concord was incubated with sulfite pads containing 0.4 g of potassium metabisulfite for one and two days prior to culturing and evaluated against a control that had been surface sterilized with 0.5% NaOCl and 70% ethanol after one week for losses due to microbial contamination. Sulfite fumigation of plant material reduced the incidence of mold infection, particularly in tissue cultures developed from fruit explants which had reductions in contamination as high as 10 fold. Continued attempts to isolate contaminants from cultures initiated from these explants showed no signs of infection.