48 



Fig. 15. 



Wild Mustard, Charlock, or Herrick. 



Brassica sinapistrum, (L). 



Arnonof the worst weeds in Ontario is the Wild Mustard, an an- 

 nual, naturalised from Europe, with fibrous roots and erect habit of 

 growth. The stem is rough, with stift' hairs somewhat scattered over 

 the surface. The branches arise from the upper part of the stem and 

 bear oblong leav'es ; and the lower leaves have one terminal large lobe 

 and several smaller lateral ones (lyre shaped). The flowei's are yel- 

 low, showy, and about f in. broad, with stout flower stalks, which are 

 more noticeable when the plant is in fruit. The pods, which appear 

 on the lower part of the stem whilst the top is still in flower, are from 

 1 to 2 inches long, and are either spreading or ascending. 



The shape of the pod is characteristic ; it is constricted between 

 the seeds, thus giving the appearance of a rounded enlargement where 

 each seed is borne. This appearance is termed " knotted." The pod 

 terminates in a two edged beak, and the two valves of the pod are 

 strongly veined or ribbed. 



The seed (See Fig. 15) is black, | in. in diameter, perfectly spheri- 

 cal, and very much like rape or turnip seed ; and it retains its vitality 

 for a long time when buried in the soil. An average plant produces 

 15,000 seeds. 



Time of floweringf, June-September. 



Time of seeding. July-September. 



Dispersal — by birds and implements, but chiefly as an impurity 

 in seed. 



Eradication. Owing to the great vitality of the seed. Mustard is 

 a very hard weed to eradicate. The seeds, once in the ground, live 

 for years and continue to germinate as they are brought near the sur- 

 face. Hence it takes patience, a great deal of labor, and a long time 

 to get rid of the weed, when it once gets possession of the land. 

 When present only in small amounts, hand-pulling is the best method, 

 provided the pulling is done before seeds have formed ; and as pei'- 

 sons pulling in a hurry cannot wait to examine for seed, it is best to 

 put the weeds, as they are pulled, in bundles where they can be buaied 

 when dry. 



When fields are overrun with the weed, it is best to proceed as 

 follows : Harrow stubble-ground early after harvest, or gang-plow 

 and harrow. As soon as the seeds have had time to sprout, cultivate 

 thoroughly ; repeat cultivation at intervals ; and rib up with a double 

 mould-board plow the last thing in the fall. Put in a hoed crop, either 

 roots or corn, the following spring, and cultivate it thoroughly through- 

 out the growing season. Cultivate and harrow well two or three 

 times after roots or corn, having first run the plow along each row of 

 corn roots to cut the roots and turn them up ; and rib up before the 

 frost. (If the plow is used after roots or corn, it is likely to bring 



