FUNGI AND PLANT DISEASE 



All 



consists of removal of infected parts of the host plants, in the case 

 of perennial species, cultivation and fertilization of soils to produce 

 a hardy, resistant plant growth, and spraying or dusting with 

 fungus-killing chemicals during the growing season when 

 numerous short lived spores are being produced. 



The Basidiomycetes include members which are more familiar 

 to the average person than either of the two groups previously 

 discussed. Two groups of these organisms, the smuts and rusts, 

 are notorious as disease producers on our cereal crops, especially 



Fig. 259. — Smuts are all internal parasites living within the tissues of the host. 



wheat and corn. The fleshy forms, commonly known as mush- 

 rooms, toadstools, and bracket fungi, are commonly found on 

 living trees, fallen logs, stumps, in pastures and fields; in short, 

 everywhere that organic matter exists in abundance, some form is 

 likely to be present, provided there is sufficient moisture. Al- 

 though the group comprises a great variety of plant forms, all 

 display a basidium at some time during the life cycle. This is a 

 club- or stalk-shaped reproductive structure which bears, exter- 

 nally, four single celled spores in most Basidiomycetes. 



The SMUTS are generally held as the most primitive of the 

 Basidiomycete group, due to their simplicity of body structure 



