BULLETIN 756, U. S. DEPARTMENT OF AGRICULTURE. 
moisture supply ; and field experiments to determine this matter defi- 
nitely were begun in the fall of 1915. 
THE EXPERIMENTS. 
If it were true that pecan rosette is merely an evidence of star- 
vation, it might be supposed that liberal applications of mineral fer- 
tilizers would relieve the condition, but such is not the case. Ex- 
periments by the United States Department of Agriculture with 
h e a v y applications 
of mineral fertilizers 
in young orchards 
located on poor soil, 
as well as the experi- 
ence of many grow- 
ers, indicate clearly 
that rosetted trees 
generally become 
worse Under such 
treatment. This 
point, taken in con- 
nection with the facts 
that the native habi- 
tat of the pecan in 
the United States is 
the flood plains of 
the Mississippi 
Eiver, its tributaries, 
and other streams of 
the South and South- 
west and that pecans 
make a uniformly 
vigorous, healthy 
growth on these soils, 
indicated that the fertility to be added should be from organic 
sources and that the physical condition and water-holding capacity 
of the soil must be improved in order to overcome the disease. Only 
by the annual addition to the soil of large quantities of humus- 
forming material could this result be obtained. 
PURPOSE OF THE EXPERIMENTS. 
The experiments were designed to demonstrate the correctness or 
incorrectness of the view stated above. It was proposed to increase 
the humus content and the fertility of the soil and thereby to better 
its physical condition and water-holding capacity as rapidly as pos- 
Fig. 3. — The tree shown in figures 1 and 2 after two com- 
plete seasons. There has been some normal loss of 
foliage, but striking improvement is evident. October, 
1917. 
