WEED GRASSES. 



33 



This is without doubt one of the most difficult twitches 

 to eradicate on arable land. The great length of the rhizomes 

 makes them very difficult to remove entire from the ground, 

 and when they are dragged to the surface their 

 great vitality makes it very difficult to secure 

 their destruction. On a certain Canterbury 

 farm whose records have been well kept, there 

 is an instance of one side of a particular 

 paddock being worked for twitch in 1886, and 

 intermittently on till 1916 a period of 30 

 years. In another instance this twitch had 

 been worked out of the ground, raked into 

 heaps and set fire to. After the fires had got 

 a good hold rainy weather set in, and there 

 was to be seen the curious sight of the heaps 

 burning in the middle and on the outside pro- 

 ducing a vigorous crop of green blades. 



As with many weeds this grass has some 

 good points. It is undoubtedly relished by 

 stock, as patches of it in a grass paddock are 

 always closely grazed. Then there are two 

 circumstances in which it is advantageous 

 to introduce Agropyrum, and both these are 

 cases where an unbreakable turf is the chief 

 requisite in the grassy covering of the soil. 

 n g rasse d sandhills, where stock are apt to 

 break through the turf and expose the sand, 

 thus forming holes which the wind may indefinitely enlarge, 

 Dr. L. Cockayne recommends this twitch. Again on race- 

 courses where the hoofs of the galloping horses tend to 

 destroy the turf, Agropyrum would undoubtedly give 

 good results. The seed is however almost unprocur- 

 able, as even where it occurs, it is very commonly 

 either quite infertile or else destroyed by ergot. The 



Fig. 18. 



Agropyrum 



repens. 

 Flower head 

 and ears at 



