GRAMINEAE (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 rootstocks and above-ground growth. In 
other words, the old rootstocks do not live over a second winter. 
Only the new ones (secondaries and tertiaries) do this. Under our 
classification, secondary and tertiary rootstocks become primary 
rootstocks at the beginning of the next season after their 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 rootstocks 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. Cates 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 rootstocks 
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 
