720 Agricultural Journal of Victoria. 



It may prove both interesting and instructive to follow tlie steps 

 whereby this take-all disease was proved conclusively to be caused by 

 a definite fungus, especially since it had hitherto baffled both practical 

 farmers and scientists in Australia. Every conceivable cause was 

 assio-ned for it. It was said to be due to exhaustion of the soil and 

 that the application of manures would remedy it ; that it was owing' 

 to too much salt in the soil, to want of drainage, to the presence of 

 insects or threadworms, and even certain weeds have been blamed for 

 it. It was also said to be in the seed and some common fungi were 

 believed to produce it, but there was no convincing proof offered that 

 any of these numerous causes were capable of producing the disease. 



In December, 1900, samples of white-heads of Avheat were sent to 

 me from South Australia, and the fungus which was afterwards found 

 to be the cause of both take-all and white-heads was determined and 

 named. There was no proof, however, that the fungus actually 

 caused the disease, since it might have attacked the plant after it had 

 been weakened and rendered susceptible from some other cause. 

 Then in November of last year the disease was particularly bad, and 

 the personal inspection of ninnerous take-all patches revealed in every 

 instance the presence of the self- same fungus, the dying or dead 

 plants being more or less blackened at the butt. It was observed at 

 the same time that the disease known as white-heads or dead-heads was 

 due to the same fungus, only the plants had sufficient vigour of 

 growth to produce the ear but not the grain, oi- at most a few small 

 shrivelled grains. 



Still it was not absolutely certain that the fungus Avas a cause and 

 not a consequence of the diseased condition, until the fungus was 

 applied to healthy wheat and the take-all produced by it. This final 

 coui-t of appeal settled the question, for on growing wheat in pots ta 

 which take-all stubble had been added, the plants became infected by 

 the disease, and in 52 days after sowing produced spores capable of 

 infecting fresh plants. The infected plants were dead or dying, while 

 the plants in the check pots, in which no stubble was put, were 

 healthy and green. 



In dealing now with take-all and its remedies, one is no longer 

 working in the dark but has a definite object in view, either to destroy 

 the fungus by direct attack with the application of various manures 

 and chemicals, or to starve it into submission by depriving it of its 

 ordinary nourishment. It was also found that the fungus can grow 

 upon the spear-grass {Bromus sterilis), and since it is highly probable 

 that the wheat may be infected from this source, the keeping down of 

 all such weeds is an important pai't of the work of overcoming the 

 disease. Experiments are being made to ascertain with certainty 

 whether wheat can be infected by the fungus taken from spear- 

 grass. 



There is just one final suggestion to make, and that is, there may 

 be some varieties of wheat more resistant to this disease than others, 

 and farmers should select seed from any special plants which seem to 

 have this property. 



