148 MANUAL OF FRUIT DISEASES 
Control. 
To the grower who contemplates planting an orchard in the 
Southwest it is advised that the list of possible host-plants be 
carefully consulted before proceeding. If it is determined that 
the pathogene is present in the soil of the site proposed for the 
orchard, it is best to wait from three to five years before plant- 
ing. Select trees from a nursery known to be clean. Orchard 
cultivation gives proper aération for the roots and at the same 
time presents conditions unfavorable to the fungus. Deep fall 
plowing has been advised for cotton; this measure may assist 
not only the cotton-grower but also his neighbor who may wish 
to grow apples. In severe cases the fungus may be isolated by 
digging trenches about infected trees, going as deep as the roots 
penetrate into the soil. All weeds, most particularly the sida, 
should be destroyed. A tree once found diseased ordinarily 
cannot be saved; this is due to the fact that there is usually no 
external indication of the trouble until the whole root-system is 
practically destroyed. Diseased and dead trees should be 
removed and destroyed. If a stump is left, it is recommended 
that the dirt be removed from about the roots, allowing them 
to dry, then that the whole stump and its root system be burned. 
REFERENCES 
Shear, C. L., and Miles, G. F. Miscellaneous papers. V. The control 
of Texas root-rot of cotton. U.S. Agr. Dept. Plant Indus. Bur. 
Bul. 102: 39-42. 1907. 
Pammel, L. H. Cotton root-rot. Texas Agr. Exp. Sta. Bul. 7: 5-30. 
(Also Rept. 2: 61-86.) 1890. 
Galloway, B. T., and Woods, A. F. Diseases of shade and ornamental 
trees. Root diseases. Southern root-rot. U. S. Agr. Dept. 
Yearbook, 1896 : 248-249. 1897. 
Stevens, F. L. Ozonium omnivorum. In The Fungi which Cause 
Plant Disease, pp. 662-663. 1913. 
Duggar, B.M. Root rot of cotton and alfalfa. Jn Fungous Diseases 
of Plants, pp. 479-481. 1909. 
