PREVENTIVE AND COMBATIVE MEASURES. G7 



to handle in such a basket would be a full half-bushel. The 

 hot water is best contained in two large boilers, the first at a 

 moderate temperature, serving to wet the grain somewhat and 

 to prevent cooling of the water of the second boiler, which 

 must be maintained between 130" F. to 134'' F. A lower 

 temperature will not ensure death of all spores, a higher will 

 injure the grain. The grain is immersed a few minutes in the 

 iirst boiler, then placed in the second for fifteen minutes, being 

 meanwhile frequently shaken to ensure complete sterilization. 

 Next the basket and its contents are cooled in cold water and 

 the grain spread out to diy.^ 



The important point in the application of these methods is 

 their general and simultaneous use throughout a whole district. 

 For smut-diseases the removal of diseased plants is at tiie 

 same time a preventive and a combative measure. This is 

 not difficult where the plant is large or the disease conspicuous, 

 as with the maize-smut ; the diseased plants can then be re- 

 moved and burnt before the smut-spores are shed. If the smut 

 is not veiy prevalent it is possible to keep it in check by 

 removal of diseased specimens on such crops as maize, barley, 

 wheat, and oats. This treatment can also be applied to some 

 garden-smuts like that on violets. 



Brefeld recommends as a preventive measure the avoidance 

 of the use of fresh farmyard manure. Smut-spores from in- 

 fected hay or straw, which finds its way to the manure heap, 

 germinate there and multiply yeast-like giving rise to conidia, 

 which, on exhaustion of nutrition, give rise to germ-tubes 

 capable of infecting seedling plants. The spores are capable of 

 germination even after being eaten with the fodder and passing- 

 through the digestive canal of animals. In this connection 

 Professor Wollny carried out the following experiment at my 

 instigation : three fields situated at some distance from each 

 other were sown with maize, which I had mixed with living 

 spores of Ustilago mayclis collected the previous autumn. One 

 field was left unmanured, the second received old farmyard 

 manure, the third fresh. All plants in the first plot grew up 

 healthy, two of the second were diseased, and eleven of the 

 third. The summer being a dry one the number of diseased 



^ In the literature issued from the United States Experimental Stations 

 otlier "steeps" are given, with results. (Edit.) 



