208 



the bulletin was written " to meet the demand for information in the 

 northern part of Indiana. A\here there has been a very unnsnal loss of 

 wheat in the ero]) just liai-vested on account of stinking smut." 



StinJilng smut (TiJIefia la^vis, Kuehn, T. foefens, Ravenel) (pp. 

 3-19). — There was a serious outbreak of this disease in La Grange 

 County, Tnd.> in 1880. In one field examined hy the author more than 

 oO per cent of the croj) was lost by reason of the smut. The subject is 

 treated under the following heads: Amount of loss, description of the 

 fungus, early oj^inions regarding it. external character, name, 

 growth, and rei^roduction, attack and spread of the disease, natural 

 checks to increase, nature of the inju.rv. remedies and precautions, 

 Tavo forms of stinking snnit are known. Tillcthi tr'tfici, common in 

 Europ:', esi^ecially in tlie British Isles, and Tilletia heris, or foetens, 

 Avhich is the j:)revaiHng form in tliis country. The spores of the 

 former are round and minutely roughened, while those of the latter 

 are rather larger, irregular, and entirely smooth. This distinction 

 can be observed only with the microscope. The author believes that 

 the name TUleti(( foetens should be adopted as the one printed first by 

 Ravenel in I860.* The disease does not spread from plant to plant 

 or frorii field to field while the crop is growing, but the infection 

 takes jdace at the time the seed sprouts. 



Sporos of tlie fuu,i;us. which are very nearly or quite in contact with the germ 

 end of the wheat grain, or touching the young plantlet between its attachment to 

 the seed and the tirst joint, can grow into the tender tissues of the plant as the 

 seed sprouts, and drawing nourishment from the .iuiees develop along with the 

 wheat, and finally ])roduee spores in the kernels. A single spore may thus cause 

 all the heads of a stool of wheat to snait. 



The spores are either in the soil or are sown with the seed. Great 

 care must therefore be taken to sow clean seed. A single smutted 

 kernel may contain several million spores, and if this kernel is 

 crushed in a bin of seed wheat and the spores thus distributed the 

 crop produced from such seed would prol3al)ly be very largely ruined. 

 The disease may also be conveyed to the seed through a thrasher, 

 fanning-mill, seeder, bin, or sack which has been used about smutted 

 Avheat and not properly cleansed afterwards. It is also probable that 

 the spores of wheat snmt, like those of corn smut, retain their germi- 

 nating power in the manure dropped by animals fed on smutted 

 wheat, and such manure should, therefore, not be used in the wheat 

 field. " When kept dry the spores retain their power of germina- 

 tion two or three years, or even longer,''' but tinder the conditions 

 found in the field prol)ably not over two years. Insufficient moisture 

 in the soil and resistant varieties of wheat seem to be among the 

 riatural checks on the increase of this disease. " Where there is 

 danger of infection do not sow wheat on wet or insufficiently drained 



* See Ravenel, Fungi Carolinian! Exsiccati, Y. 1860, No. 100. 



