00374nam a2200145Ia 4500008004100000082001600041100002500057245002000082250000600102260005100108300000800159650002300167650001800190653002000208170901s1950    xx            000 0 und d  a581.2bW13P  aWalker, John Charles 0aPlant Pathology  a1  aNew YorkbMcGraw Hill Book Company, Inc.c1950  a699  aBotanical sciences  aPure Sciences  aPlant pathology