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  2. Huth, Phytopath. Z. 62: 300, 1968.
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  5. Serjeant, Ann. appl. Biol. 59: 31, 1967.
  6. Smith, Pl. Path. 1: 118, 1952.
  7. Upstone, Ann. appl. Biol. 64: 49, 1969.