Potential for biological control of Botrytis cinerea in Pinus sylvestris seedlings

Grey mould (Botrytis cinerea Pers.: Fr.) is the most common economically important fungal disease in Swedish forest nurseries. In tests in a growth room, foliage of predisposed (preinoculation incubation at 35degreesC for 4 days) Scots pine (Pinus sylvestris L.) seedlings was sprayed with suspensions containing Mycostop(R), Binab(R) TF. WP or GlioMix(R) at concentrations of 0.5, 1 or 0.5 g l(-1), respectively, and/or conidia of B. cinerea (10(6) spores ml(-1)). Binab and GlioMix reduced grey mould in needles by 94 and 92%, respectively, and were as effective as the fungicide Euparen(R) M 50 WG, while Mycostop reduced disease by 51%. In one trial in a forest nursery, Mycostop, Binab and GlioMix, each applied two and four times during the growing season, suppressed spontaneous B. cinerea infections in needles of first year container-grown P. sylvestris seedlings by 16-57%, and were as effective as recommended fungicidal sprays. It was concluded that biological control has potential to effectively suppress grey mould in seedlings in forest nurseries.