4 lutrodnciion. 



If we follow the spore of the Stinking Smut of wheat from the time it is 

 shed until it reaches a fresh plant next season, the way in which the disease 

 is carried from season to season will be evident. In a district where this smut 

 occurs, the sound grain may receive the spores by means of the wind or in the 

 threshing machine, and this seed with the adhering spores may be sown in 

 the same or in another district and thus introduce the disease. The grain 

 in due course germinates, and the self -same conditions which are favorable 

 to the germination of the wheat also suit the smut spores. They readily ger- 

 minate with moisture and produce secondary spores, or conidia, which in turn 

 put forth delicate threads, and these readily enter the young wheat seedling. 

 There they soon reach the growing point of the stem and continue to grow, 

 plant and parasite being supplied Avith food from the same source. Under 

 ordinarv conditions of growth the wheat-plant is able to provide sufficient 

 food material for both, and this goes on until the flower is formed and the 

 young ovary begins to develop. Then the plant ceases to manufacture fresh 

 material and transfers what has already been accumulated to the grain, for 

 the benefit of the young and growing embryo. Here the fungus luxuriates 

 in the rich supply of food and the filaments increase, multiply, and divide 

 into innumerable branches, from each of which spores are formed ; the wall 

 of the filaments becoming gelatinous. The wall soon deliquesces and is 

 absorbed by the growing spore, which soon assumes its firm black covering; 

 and what was at first intended as a store-house of nourishment for the embryo 

 has been converted into a charnel house, densely packed with the spores of 

 the overmastering fungus. These spores again reach the sound grain and 

 repeat the process in the succeeding crop. The principle on which the treat- 

 ment for the prevention of this smut is based, may be clearly seen from this 

 brief account, for if the spores on the grain are destroyed, or their germinating 

 power arrested, they will not be able to infect the young seedling and pro- 

 duce the disease. 



The losses caused by this smut are enormous, and these are not only due 

 to the actual reduction in the yield of grain, but to the indirect loss brought 

 about by the sound grain having its commercial value lessened from the ad- 

 hering spores of smut, which are easily recognised by their objectionable smell. 

 It was estimated, from reliable data, that in one season this State suffered a loss 

 of £50,000, although in recent years the general treatment of the seed-wheat 

 has reduced considerably this preventable loss. Even the loss from Loose 

 Smut of wheat is considerable, although the farmer does not always allow 

 for it, and may even blame something else for the naked stalks throughout 

 his crop. In South Australia, it is considered that in some seasons more 

 damage is done to wheat by Flag Smut than even by the dreaded Rust, and 

 in certain districts of Victoria the yields are much reduced from that cause 

 alone. 



In the countries of the Old World, the loss due to smut is regarded as only 

 surpassed by that caused by Rust, and in the United States, Swingle'^ has 

 calculated the yearly loss from Oat Smut to amount to £3,600,000, and for 

 the State of Ohio alone, Selby- has reckoned the Stinking Smut of wheat to 

 cause a loss of £50,000. For both these diseases a remedy has been provided, 

 and it Hes with farmers themselves to take advantage of it. 



Historical. — While the mildew or rust of wheat is freely mentioned by 

 ancient w-riters, the smut of wheat is not specially noticed, and there is no 

 word to express it in the language of Greece or Italy. Pliny speaks of the 

 blasting of corn " which cometh of some distemper of the air," but this, in 

 all likelihood, refers to Rust, for he goes on to remark " this unhappy blast 

 falleth most often in places subject to mists and dews, such as hollow valleys 

 and low grounds." It does not necessarily follow, however, that it was not 



