Experiments were conducted on the factors involved in the induction of dormancy in wild oats. I t was shown that when the supply of air reaching the embryo of imbibed seeds is restricted, changes occur in the caryopses so that when the seeds are subsequently dehulled and the caryopses exposed to air they are unable to germinate. Induction of dormancy is greater a t 2S°C than a t 7" C. The site of the mechanism controlling induced dormancy is in the embryo or endosperrn rather than in the seed coat or hulls. If dormant caryopses are punctured they germinate even when the wound is covered with lanolin or agar. Inhibitors were found in methanol extracts of both dormant and nondormant caryopses, but it was concluded that they are not responsible for induced dormancy. An inhibitor which leaches from the hulls of wild oats colnpletely stops growth of excised embryos but dormancy can be induced in the absence of hulls. Dormant caryopses absorb 2,3,6-triphenyl-tetrazolium chloride but are unable to reduce this dye. The mechanism of induced dor~nancy is discussed.

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A study was made of: 1) the response of some pasture weeds of Eastern Canada when fertilizers were applied; 2) the productivity of pastures sprayed with 2,4-D, and 3) the over-all response when both fertilizer and 2,4-D were applied. Populations of orange, yellow and mouse-ear hawkweeds, ox-eye daisy, chicory, bugleweed, strawberry and wild carrot were decreased when nutrients were added but the numbers of dandelion, Canada thistle, tall buttercup, shore horsetail and yarrow were unchanged. Fertilizer not only improved the quantity but also the quality of the forage by reducing the weed content. Yield of total vegetation was not increased when weeds were controlled by 2,4-D but the forage consisted almost exclusively of desirable grasses. Best results from the standpoint of both yield and absence of weeds were obtained when fertilizer treatment was supplemented by applications of 2,4-D.