RErOLT OF THE BOTANIST 273 



SESSIONAL PAPER No. 16 



branching smaller roots, while field bindweed, has an extensive system of white, cord- 

 like, easily broken, perennial roots, which reach deeply into the earth when the subsoil 

 is not too hard. From these roots, freely budding root shoots are produced, and it is 

 by means of these that a patch once started in a field enlarges its area, and it is by 

 their breaking up and distribution as much as by seeds, that new patches are started. 

 Tt is a matter of common observation that- in some localities, the seed is only very 

 sparingly produced, although in others, unfortunately, enough is produced to provide, 

 for its constant introduction into new localities through the medium of the clover 

 seed with which it has matured. Besides the differences noticed in the root systems, 

 these two weeds show such dissimilarity in their flowers that they need never be con- 

 founded at that stage. The flowers of buckwheat are small and inconspicuous; those 

 of bindweed are over an inch in diameter, white or pinkish in colour, and of the shape 

 and appearance of small morning-glory flowers. The leaves of the two plants bear some 

 resemblances but those of bindweed are blunter at the tip and base generally smaller. 

 The stems in both cases twine about neighbouring plants for support, thus entangling 

 them and dragging them down; or in the absence of any support, they creep about, 

 forming a dense mat on the ground. 



Immediately on the discovery of the first patch of bindweed in a previously clean 

 field, steps should be taken to prevent its spread, and above all to keep it from spread- 

 ing to any permanent fence or other obstruction to cultivation. If the area is not 

 already too large, hand cultivation and hoeing will be best, as it can be more thor- 

 oughly done and greater care can be exercised to avoid the scattering of pieces of the 

 roots. The aim should be to cut off all vegetation below the surface of the ground, 

 throughout the entire growing season, and as promptly as possible at each new appear- 

 ance. This may have to be kept up for two or more seasons, depending on how faith- 

 fully it has been done. It involves much work, but nothing less will suffice, for every 

 day that new foliage is allowed to spread itself to the sunlight, it is replenishing tho 

 lost vitality of the roots. 



The difficulty of doing the work is much increased when the area to be cleaned is 

 greater. In this case, field implements must be used, and it is practically impossible 

 to avoid missing some shoots. A broad-share cultivator is the best implement avail- 

 able on most farms, and should be used in preference to the disc-harrow for this weed. 

 If' a whole field is infested, it will be economy in the long run to keep it bare-fallow 

 for at least one season, which applies equally to such portions of a field as may be 

 infested. If a late-sown cultivated crop, like turnips or pasture rape in drills, suc- 

 ceeds a year of bare-fallow, the opportunity thus given before and during the growth 

 of the crop, for further cultivation, will do much to subdue the weed. In fts weakened 

 condition, it can be smothered with a crop of grain thickly seeded to clover, or better 

 still by a seeding of lucerne without the grain. Any plants which survive must there- 

 after be given special attention with the hoe or otherwise until disposed of, or the field 

 will soon be as foul as before. 



When bindweed gets established in berry plantations, gardens, and similar places, 

 it will usually be best to remove the crop to another location, as very little headway 

 can be made in fighting the weed among them and their supports. 



As an* alternative to cultivation and the hoe as a means of preventing growth 

 above ground, it is frequently recommended to cover the area to be cleaned with build- 

 ing paper, litter, etc. This, of necessity, can be practised over only very limited areas. 

 Even then it is doubtful whether the saving of labour is sufficient to offset the cost 

 of the treatment. The building paper to be effective must be well overlapped, and in 

 all probability will have to be renewed at least once before the bindweed is subdued. 

 Any other covering must be of considerable depth, for bindweed is capable of growing 

 through a couple feet of straw mulch. Unless there is some special condition whinh 

 renders these methods desirable, better results may be expected from work such as has 

 been outlined above. Other methods, such a's the application of salt or chemicals, havo 

 not yet been demonstrated to be of much advantage. 



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