PLATE 5. 



WILD MUSTARD, Brassica Stnapistrum, Boisi. 



Other English names : Charlock, Herrick, Cadluck, Field-Kale, On- 

 tario Mustard. 



Other Latin names : Sinapis arvensis, L., et auct. plur. ; Brassica 

 Sinapistrum, Benth. 



(Noxious: Dom., Man., N.W.) 



Annual. Introduced from Europe. Now found in all parts of Canada, 

 but most abundant in the Eastern Provinces and Manitoba. The erect 

 branching stems 1 to 3 feet high, rough with stiff, somewhat defiexed, hairs. 

 Lower leaves stalked, usually deeply indented or lobed, with the terminal lobe 

 large. Upper leaves mostly sessile. Flowers bright yellow, fragrant, § inch 

 broad. Seed pods 1 to 2 inches long, knotty or slightly constricted between 

 the seeds, ribbed and ascending, on short thick pedicles, tipped with a long 

 empty or 1-seeded 2-edged beak, which comes away whole from the ripe pod. 

 Seeds [Plate 53, fig. 4r^natural size and enlarged 8 times] round, about 15 

 to 17 in each pod, very dark brown or reddish black and almost smooth, no 

 mucilage. The seeds have great vitality ; an actual proved instance of their 

 having lain in the ground in a salt marsh in Nova Scotia for twenty years is 

 known to me, and another of Wild Mustard appearing abundantly on the 

 ploughing lip of a pasture which had been down for twenty-four years. A 

 purple patch at the junction of the branches with the stem is a striking char- 

 acter of this Mustard. 



Time of Flowering : June to September; seed ripe by August. 



Propagation : By seeds only. 



Occurrence : In all farm crops and in waste places. Distributed in crop 

 seeds, by floods aud wind, and in manure. 



Injury : A gross feeder and recognized generally as an indication of neg- 

 ligent farming. 



Remedy : Hand-pull regularly if only in small numbers. Harrow stub- 

 bles as soon as the crop is harvested to start autumn growth ; cultivate down 

 the first growth or feed off with sheep. Leave late plants, which the frosts 

 of winter will kill before seeds ripen. Spraying young Mustard plants with 

 a 2 per cent, solution of bluestone (sulphate of copper), that is, 2 lbs. of 

 bluestone in every 100 lbs. (10 gallons) of water, has given very satisfactory 

 results. The bluestone solution falling on the leaves and tender stems of the 

 Mustard kills them in a few hours without any injury to the grain or grass 

 crop amongst which they are growing. The work must be done when the 

 Mustard is quite young and succulent, that is, when the first flowers are 

 opening. A barrel, 40 gallons, will almost cover an acre if used with care 

 and put on at the best time, before the plants are too large. The cost is 

 about 80 cents per acre. This method is a practical one in Ontario, where 

 water is plentiful and labour and implements are cheap. In the West this 



23 



