182 Principles of Plant Culture. 



The affected part should be removed as soon as dis- 

 covered and burned at once, to destroy any spores of 

 the fungus it may contain or which might mature; later. 

 It is generally important to cut the diseased branch 

 some distance below the point of visible infection, as in 

 many cases the mycelia of the fungus extend farther 

 than external appearances indicate. 



324. Preventing Spore Germination is the only 

 known method by which we can combat the fungi de- 

 veloping ivithin the host plant {endophytic (en-do- 

 phyt'-ic) fungi). 



In fungi that develop from spores planted with the 

 seed, as the smuts of the small grains, spore germina- 

 tion may be prevented by treating the seed with a solu- 

 tion of certain chemicals or with hot water. Of the 

 former, formalin is now most used, and unquestionably 

 destroys the spores of the smut, and while it has gen- 

 erally been found to injure more or less the germina- 

 tion of the seed, it is now recognized as the most effi- 

 cient and practical method of treating seed for the 

 prevention of smut in wheat, oats and barley. 



325. The Formalin (formaldehyde) Treatment con- 

 • sists in immersing the seed in a solution of formalin 



in water. To treat seed oats for the prevention of 

 smut prepare a solution of one pound (pint) of forty 

 per cent formadehyde (formalin) in thirty-six gallons 

 of water. The seed should be submerged in this solu- 

 tion for ten minutes and then, spread on a canvas or 

 floor to dry. 



* JHurncifftfifi Ccpulne. 



