465 



DESTRUCTION OF CHARLOCK. 



This weed, which is common in cultivated fields throughout 

 the whole of Great Britain, is known under a variety of names, 

 such as yellows, yellow weed, skellock, runches, wild mustard 

 (Brassica Sinapis Vis., B. Sinapistrum Boiss., Sinapis arvensis 

 L.). In general appearance it closly resembles the turnip, 

 to which, in fact, it is very nearly related. As in the case of 

 other plants of the same family, charlock seed contains a 

 large amount of oil, and this is at least partly accountable 

 for the persistent vitality often exhibited by this seed. Land 

 that has been under grass for many years may thus, 

 when broken up, show an abundant growth of this weed, and 

 the same state of things not infrequently attends extra deep 

 cultivation, and the consequent disturbance of dormant seeds. 



Everything considered, charlock is perhaps the most 

 troublesome weed with which the farmer of arable land has 

 to contend. In corn crops its growth is often so rank as to 

 seriously reduce the yield of grain. In root and bean crops 

 the weed can be more easily dealt with ; but here also it often 

 proves very injurious, and especially so when the conditions 

 of the weather or scarcity of labour prevent its timely eradi- 

 cation. As a rule it is not conspicuous amongst rotation 

 grasses or clover, and it is practically absent from permanent 

 grass land. 



The injury induced by charlock is partly direct and partly 

 indirect. It competes with crops for light and air; that is U 

 say, it overgrows more or less, completely and smothers, 

 other plants with which it is associated. It also robs crops 

 •of a part of their nutriment, and prevents their deriving full 

 benefit from the moisture of the soil. But in other ways — 

 though more indirectly — this weed may be the cause of 

 much loss. The turnip " fly/' for instance, would be unable 



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