SOME DISEASES OF PECANS 
By Frederick V. Rand, 
Scientific Assistant, Fruit-Disease Investigations, Bureau of Plant Industry 
INTRODUCTION 
The pecan, Carya illinoensis (Wang.) K. Koch, 1 is an indigenous tree 
of the hickory group, which has long been famous for the excellent quality 
of its fruit. From the time when the earliest settlers first gathered the 
nuts from native forest trees the pecan has been growing steadily in 
favor. 
Until recently the entire supply has come from the wild forest trees 
and from a comparatively few, more or less isolated seedling orchards. 
During the last 15 years, however, artificial propagation by budding 
and grafting has gradually assumed a commercial importance until at 
the present time a large number of excellent horticultural varieties are 
available. These are being planted on a large commercial scale and 
through an ever-widening range. 
The pecan is found native on low, rich ground in the neighborhood of 
streams from the valley of the Mississippi River in Iowa through south¬ 
ern Illinois and Indiana, western Tennessee to central Alabama and 
Mississippi, western Louisiana through Arkansas and Missouri to south¬ 
eastern and western Kansas, eastern Oklahoma, and the valley of the 
Concho River, Tex. It is also found in some of the mountain regions 
of Mexico. As a native tree the pecan is most abundant and attains 
its largest size in southern Arkansas, eastern Oklahoma, and middle 
to eastern Texas. 2 As a cultivated tree, however, it is by no means 
confined to the sections above enumerated. Plantings of greater or 
less extent have been made in Virginia, North Carolina, South Carolina, 
Georgia, Florida, New Mexico, California, Oregon, and Washington, with 
small experimental plantings in several other States. 
Notwithstanding the highly colored statements of some of the early 
promoters of pecan culture, this tree, like all of our cultivated fruit trees, 
has its insect and fungous enemies. Possibly they would form a shorter 
list than would those of some of our common fruits, but they are none 
the less real and important, for, whenever a plant is brought under culti¬ 
vation or taken out of its native range, new diseases and new problems 
with old diseases are sure to follow. 
Other things being equal, the larger the number of individuals of a 
host species growing in a given area the greater the chances any particu- 
1 Synonyms: Carya oVvnaeformis Nutt.; Hicona pecan Brit.; Juglans pecan Marsh. 
2 Sargent, C. S. Manual of the Trees of North America. Boston, 1905, p. 134. 
Journal of Agricultural Research, 
Dept, oi Agriculture, Washington, D. C. 
(303; 
Vol. I, No. 4 
Jan. 10. 1914 
