w HEAT ( I i.Ti RE 



351 



head, but more commonly two or three straws develop. Often it will be 

 iced thai other straws have Btarted but failed to develop (Fig. 19). 

 Sometimes an extreme unevenness of relative development in the straw and 

 heads <>f the individual plants is noticed (Figs. 20 and 21). If diseased 

 plants are more carefully examined, the butts will be found to be " tobacco 

 coloured " or " cresote coloured " near the ground level, and to have a very 

 poorly developed root system. Microscopic examination shows that th< 



Fig. 18.— Plants that have died of Foot Rot in various stages of development. 



-tools, roots and basal parts of the st caws are destroyed by the invasion of 

 the parasitic fungus ffelminthosporium. If the crop is examined in a late 

 stage, the tobacco coloured part of the straw is seen to be rotted and to have 

 turned to an ashen grey colour. When pulling the plants up the brittle 

 roots break off near the butts. The leaves may show symptoms in a moist 

 climate, spots of an elongate type, yellowish, and with black and brown 

 centres being developed. 



