PLATE 12 



Blades and sheath of com showing the Physoderma disease produced by inoculating 

 plants in the greenhouse with a suspension of the sporangia of P. zeae-maydis in tap 

 water. The suspension was poured behind the sheaths and in the bud of the plants 

 and the plants were sprayed twice daily to keep them damp. Notice the dark area 

 around the diseased tissue in the bottom figure. This is a dark-red color which is 

 often seen on diseased plants in the field. 



