Boscalid is a broad-spectrum carboxamide fungicide that inhibits fungal respiration by binding to the ubiquinone site of mitochondrial complex II/succinate dehydrogenase.¹It suppresses mycelial growth ofS. minorby 87 to 100% and ofS. sclerotiorumby 77 to 100% when used at a concentration of 1 µg/ml.²In field studies, boscalid applied at 5.6 µg/cm²provides 55.5 and 30.4% disease control for lettuce drop caused byS. minorandS. sclerotiorum, respectively. It decreases cell viability of mouse primary cortical neurons following long-term exposure but is not cytotoxic (LC₅₀= >100 µM for acute and continuous exposure). Formulations containing boscalid have been used in agriculture to prevent fungal growth on crops.

1.Wang, Y., Duan, Y., Wang, J., et al.A new point mutation in the iron-sulfur subunit of succinate dehydrogenase confers resistance to boscalid in Sclerotinia sclerotiorumMol. Plant Pathol.16(7)653-661(2015) 2.Matheron, M.E., and Porchas, M.Activity of boscalid, fenhexamid, fluazinam, fludioxonil, and vinclozolin on growth of Sclerotinia minor and S. sclerotiorum and development of lettuce dropPlant Dis.88(6)665-668(2004)