Tahe-all and White-heads in Wheat. 411 



Symptoms of Disease. 



It is necessary at the outset to imderstiind clearly what we mean by 

 take-all, for the vagueness of the term, or rather its comprehensive- 

 ness, might lead to almost anything being included under it which 

 killed the plants at a comparatively early age. While investigating 

 take-all this season, I have met with patches in the crop, in which a 

 prevalent weed had grown so thickly as to smother completely the 

 young wheat-plants. That this is often mistaken for take-all is shown 

 by the fact that quite a number of weeds have been regarded and 

 given as the cause of it. In other cases, there were patches where 

 the land was boggy, and the root-rot which brought about the death 

 of the plants was evidently due to this. Again, where trees have 

 been burnt upon the ground, the crop on these patches may also go 

 off. Excess of potash on burnt soil may possibly favour the fungus 

 and likewise be injurious to the wheat, and such a combination would 

 soon lead to the death of the plants. Excess of nitrogenous mature 

 too is unfavourable, and where old sheep camps have been, there the 

 plants may die out. 



But the true take-all, that which is regarded by the observant 

 farmer as such, had invariably a special fungus at the butt of the stem 

 or on the roots, either in its vegetative or reproductive stage, so that 

 the term has now a definite meaning, and applies to wheat-plants which 

 have succumbed to the attacks of this particular fungus. The fungus 

 origin of the disease at once explains the various symptoms observed. 



The general symptoms have already been given, but if the disease 

 is followed from its earliest appearance, it will be seen that plants 

 succumb at various stages of growth, according to the time and 

 severity of the attack, the nature of the season, and the condition of 

 the plants themselves. 



In some spots or patches where the fungus is very prevalent, and 

 the young plants are attacked early, the disease may appear before 

 the formation of the stalk. They assume a sickly appearance, having 

 lost their dark-green colour, their leaves turn yellow, and soon they 

 shrivel up and die. Again, the attack may be later, or the plants are 

 better able to withstand the fungus, and so they linger on longer, but 

 ultimately die. The fungus spreads from a centre, attacking the 

 plants in its vicinity, and so dead patches occur here and there 

 throughout the crop, to which the name of take-all is given. But it 

 was quite common this season for the wheat-plant to produce its ears 

 and look as if it were going to fill them, but suddenly as it were, 

 they became bleached as if prematurely ripe, and the jilant died 

 from the root upwards. Every gradation has been met with 

 from the take-all in which the plants died young to the white- 

 heads in which the ears consisted of mere empty husks, or if 

 the grain formed, it soon shrivelled and did not come to maturity. 

 The farmer noticed the two seemingly distinct stages, and named 

 them accordingly, but generally failed to see that the wheat- 

 plants were dying off at different stages in various portions of the 

 crop. In some soils, especially rather firm sandy loams, the early 



