Abstract
An in vitro technique for large-scale production of sclerotia of Sclerotinia sclerotiorum was developed and tested with 12 isolates. The growth medium consisted of 54 g of cornmeal, 3.5 g of vermiculite, and 37.5 ml of a solution of 1% casamino acids and 1% yeast extract. These ingredients were mixed in a 946-ml canning jar, and the water potential was adjusted to -25 bars. Production of sclerotia by the 12 isolates ranged from a mean of 1,404 to 2,296 per jar of medium with weights ranging from 22.6 to 35.8 g. The mean sizes of sclerotia varied from 4.3 to 5.7 mm. In 12 jars of medium, 17,768 sclerotia were produced with isolate ND21. The procedure, termed the cornmeal-vermiculite technique, appeared to have no adverse effects on the biology of sclerotia.