FRUIT TREES—WINTER KILLING OF 
curl, peach tree borers, extremely dry 
condition of the ground in some sandy 
and gravelly ridges, “water-logged” soils, 
ete. 
Injury on Bare Ground 
There was a marked contrast in the 
extent of the winter injury on bare soils 
—soils given clean cultivation—and on 
covered soils. The bare soils froze deeper 
and the injury was much greater than on 
soils covered with a mulch or other ma- 
terial. The greater depth to which bare 
soils freeze in winter than covered soils 
was brought out in an experiment made 
at the station. A plat of peaches in an 
exposed situation was selected and a 
strip of sod 10 to 12 feet wide removed 
from one row, leaving the bare surface 
of the soil fully exposed to the cold. 
Another row alongside was left in 
grass which had been clipped and al- 
lowed to lie upon the ground. + When the 
sod was removed the ground froze to a 
depth of 18 inches, while under the thin 
sod covering of grass and weeds in the 
other row the ground froze to a depth 
of about eight inches. The trees in the 
bare ground “were very slow in starting 
into growth the following spring of 1904. 
All of the trees in this row were seri- 
ously injured by the cold, many large 
branches dying, while in one case the 
entire tree was so badly injured that but 
few leaves appeared throughout the sea- 
son, and these upon shoots so feeble and 
slender that the tree might well be con- 
sidered dead. Later in the season, how- 
ever, some of the trees rallied slightly, 
though all showed a serious lack of vital- 
ity. The trees in the sod * * * did 
not suffer in the least degree—all mak- 
ing a healthy, uniform growth during the 
season of 1904.” 
Value of Cover Crops 
The value of an annual cover crop as 
compared with clean cultivation was 
found in an orchard 18 years planted, 
one-half of which had been cultivated 
during the first half of each season and 
then sown to crimson clover, while the 
other half was given clean cultivation 
+See United States Department of Agricul- 
ture, Farmers’ Bulletin 202, p. 11. 
10383 
during the growing season. “Upon the 
clean culture area there was a much 
greater percentage of injury from the 
cold of the winter than upon the crim- 
son-clover section. Where the clover 
crops had been grown and plowed down 
the trees showed remarkably healthy, 
heavy, dark-green foliage, contrasting 
sharply with the yellowish, sickly foliage 
of the clean culture plat.” Another grow- 
er in the injured peach region stated 
that “not a single orchard or section of 
an orchard of which he knew, that had 
received even a light dressing of barn- 
yard manure within the last year or two, 
had suffered noticeably from cold.” 
Injury in Scale-Infested Orchards 
A 13-year-old orchard of 660 trees was 
found located on shallow limestone soil 
covered with a dense, heavy growth of 
bluegrass. The San Jose scale had 
wrought havoc in the neighborhood, but 
it had been kept under control in this 
orchard by spraying. As a result, not a 
tree in the whole block was killed by 
cold. Across the road from this orchard 
was another, located on similar soil and 
also in sod, but in which the scale had 
not been controlled. “The story is told 
in two words—entirely dead.” 
Injury from Leaf Curl 
Another instance is cited in which an 
orchard was sprayed in the spring of 
1902 for the control of the scale, with 
the exception of three rows through the 
middle, which were overlooked. As a 
result, the scale increased rapidly during 
this season on these unsprayed trees, and 
they were also attacked by leaf curl, 
which practically defoliated them. The 
whole orchard was sprayed in 1903, nev- 
ertheless the trees had been so weakened 
by the leaf curl of the preceding year 
that the good care given them in 1903 was 
unavailing, and every tree in the three 
rows was killed, while every tree on 
either side of them which had been 
sprayed came through the winter sound, 
vigorous and healthy. 
Benefits from Banking Trees 
A simple, easy, and very effective meth- 
od of preventing winter killing of peach 
trees was observed in the orchard of one 
