Take-all and White-heads in Wheat. 419 



^'Journal of Agriculture for Soutli Australia " (22), and therein is the 

 first record of this fungus for Austi'alia. 



But the fungus existed here on the wheat-])lant about fifty years 

 previously, having been known in South Australia since 1852, although 

 its nature was not recognised. Mr. Ey, analytical chemist, in giving 

 his evidence before the Commission in 1868, said : — ''A plant taken 

 from a diseased spot will be found black on the stem, from the roots 

 to the first internode; and on pressing, a thin film of lichen or moss 

 will come off. In this will be found a number of animalculae coiled 

 up, apparently dead. I have not yet satisfied myself whether the eel 

 or the lichen is the primary cause ; but one of the two is take-all." 

 He was right in this last conjecture, only his so-called moss or lichen 

 Avas undoubtedly the j^hi-te mycelium stage of the true take-all 

 fungus, but unfortunately he gave preference to the eel worm theoiy, 

 and so the fungus was not further followed up. 



It is also evident from a careful consideration of the drawings 

 given by Dr. Carl Muecke (2), in his essay on take-all, published in 

 1870, that he observed within the stem of affected wheat-plants, the 

 mycelial condition of the Opliioholus, as sotne of these drawings are 

 exactly similar to Fig. (l Unfortunately, however, he did not 

 recognise its true nature, as he refers to it as a " sort of lumber " 

 within the cells, and confused the root-hairs, which are generally 

 produced in abnormal numbers on diseased plants, with the mycelium 

 of another fungus, a harmless saprophyte, called by Baron von 

 Mueller, Xenodochus cerealium, and concluded that the disease was 

 the result of starvation, the exhsvustion of the supplies in the soil of 

 certain necessary substances. 



Te])per (9), in a thoughtful paper on Take-all and its Remedies, 

 state that the disease " is nothing else than starvation of the crop," 

 and naturally recommends manuring. Extended investigation, how- 

 ever, would have shown him that the dreaded disease may appear 

 even when the necessary manures have been supplied to the crop. 



Dr. Cobb (10), in 1892, came to the conclusion that take-all was 

 caused by a fungus, and he considered it to be the common blackish- 

 olive mould, which occurs generally on the dead or decaying portions 

 of plants, but may also occur on the living. He, therefore, named 

 Cladosporiiim herbaritm Link, as the take-all fungus, but since this 

 fungus is almost universally regarded as harmless, and has rarely 

 been found on the diseased specimens sent to this branch during the 

 ])ast three seasons, this view cannot be regarded as substantiated. 

 But the wheat-stem-killing fungus stands on a different footing. Not 

 only has every take-all and white-head patch examined in the paddock 

 this season, been found to be attacked by this fungus, as well as the 

 numerous specimens sent from different districts, but the ultimate 

 court of appeal has been referred to, and infection experiments have 

 proved that the wheat-stem-killing fungus produces the disease 

 known here as take-all and white-heads. 



