OR A MINE 'AE (GRASS FAMILY) 25 



the primary rootstocks (i.e., those that were in the ground at the begin- 

 ning of the growing season in spring) all decay in the fall, after the 

 growing season is over. Their strength has been taken up in the 

 formation of secondary rootstoeks and above-ground growth. In 

 other words, the old rootstoeks do not live over a second winter. 

 Only the new ones (secondaries and tertiaries) do this. Under our 

 classification, secondary and tertiary rootstoeks become primary 

 rootstoeks at the beginning of the next season after then- formation, 

 and they, in their turn, send out secondary growth to reach the sur- 

 face ; the plant formed at the surface then sends out from the base 

 of its crown, about the time it blossoms, the large, deep-burrowing 

 tertiary rootstoeks which, in the soft land of the cultivated cotton and 

 corn fields, cause so much mischief the following year. The longer the 

 plants are allowed to stand after blossoming, the larger and deeper these 

 tertiary stems become." 



Acting on this study of the rootstock habits of Johnson-grass, 

 Mr. Gates advises the turning of infested land into meadow or 

 pasture and keeping it so persistently mown or grazed as to allow 

 it no opportunity for bloom ; then the tertiary growth of rootstoeks 

 will be small and near the surface, enabling the farmer to clean out 

 the grass the next year by a little extra care in plowing and cul- 

 tivating. As a soiling crop the grass may be cut every month 

 from May until November, and this will leave little energy to be 

 given to the formation of the deeper rootstocks. 



Professor Killebrew, of the Tennessee Agricultural Experiment 

 Station, says that the way to keep the grass in subjection is to plow 

 the land and allow hogs to pasture on the juicy rootstocks, which 

 they like better than artichokes. Rotation with winter grains, 

 such as oats, barley, or rye, is practiced in many sections, wheat 

 being too late in maturing. The ground is plowed in late summer 

 and as many of the rootstocks are harrowed out as possible ; then 

 the grain is sown in early fall and harvested in the spring, before 

 blooming time for the grass, after which three crops of Johnson- 

 grass hay may be cut during the summer. 



Professor Spillman, Agrostologist of the Bureau of Plant Indus- 

 try, believes the best plan to be the sowing of infested land with 

 alfalfa, after harrowing out as many of the rootstocks as possible, 

 early in the fall, in order to allow the alfalfa to get a good start be- 

 fore winter. The next season cut promptly, whenever the grass is 

 tall enough to make a fair crop of hay. This treatment encourages 

 the clover and discourages the grass, which will finally be crowded 



