174 Journal oj Agnciilturc. [lo March, 1909. 



developed ears were bunted, the germ-tube had evidently reached the 

 growing point of the seedling and the mycelium had kept pace with the 

 growing plant. 



11. Why are some cars only partially bunted? 



Under ordinary conditions the whole of the grains in an ear are affected, 

 but in certain seasons it is not unusual to hnd ears in which the grain is par- 

 tiallv bunted and partially clean. It may be that one side of the ear has 

 escaped, but usually the sound grains are interspersed among the bunted. In 

 one case the lower grains were all bunted, then about the middle an occa- 

 sional one was clean, and at the top both smutted and sound occurred, the 

 topmost grain, however, being diseased. The normal condition is that all 

 the grains in an ear are attacked, and when some escape it can only be owing 

 to the spore-bearing hyphae failing to reach these particular grains. It might 

 be thought that the grains which escape the invasion of the fungus to form 

 spores, had some resisting power, but when the clean grains in a partially 

 bunted ear were infected and sown, they produced bunty plants, showing 

 that there was nothing in the grain itself to account for its escape. 



12. Why are some grains of ivJieat only partially bunted'? 



This was a comparatively rare occurrence, only appearing in one ear of 

 the ^•ariety known as Cedar grown at Dookie, and in one ear of Genoa 

 grown at Burnley. In the latter ear there was only one grain partially 

 bunted, three entirely bunted, and all the rest free. In the partially bunted 

 grain the fungus had evidently exhausted itself in producing its spores only 

 on one side, and why the whole of the starch was not utilized in the forma- 

 tion of spores, might be due toi the slow growth of the fungus, enabling the 

 contents of the grain to harden so that it could not penetrate. In fact, in 

 all these cases, whether it is smutted and sound plants on the same stool, 

 or smutted and sound grains in the same ear, or even when the grains are 

 only partiallv smutted, the explanation is the same, that by some accident 

 of growth the fungus did not undergo its full development, and was unable 

 to reach all parts of the plant as usual. 



II.— Treatment of Stinking Smut of ^Wlieat. 



Since it has been clearly shown that this smut is reproduced from spores, 

 it is evident that if the spores can be destroyed or their germination pre- 

 vented, the smut itself will not appear, and it is on this principle that the 

 direct treatment for smut is based. In the case of this smut, where the spores 

 adhere to the grain and infection occurs in the young seedling, all that is 

 necessary is to treat the grain with some substance which, while harmless 

 to the grain, will destroy or prevent the germination of the spores. 



Quite a number of substances have been used for this purpose and found 

 more or less effectual, but there are only two which are generally used by 

 farmers in Australia on account of their ease of application and comparative 

 cheapness, and that is, first, a solution of sulphate of copper or bluestone. 

 and second, forn-.aldehyde, the trade name of which is formalin. 



All methods of seed treatment known dei)end for their success to a large 

 extent on the precautions taken to prevent re-infection after dipping. Care- 

 less farmers put the pickled grain into smut-infested bags or omit to clean 

 the drill. ]f the seed-box contains bunt balls or spores of the smut, the 

 treated seed will be in part at least affected. 



Bluestone Treatment. 

 This is the one most commonly used here, and consists in making a solution 

 at the rate of i lb. of bluestone to 5 gallons of water, or a 2 per cent, solu- 

 don. The seed is then placed in sacks and immersed in this solution until 



