The Delta independent., 1902-08-29
The Rosefse OF the Apple.
WENDELL PADDOCK =

WENDELL PADDOCK
peculiar condition OF apple trees on
Rogers mesa in Delta county was recent
ly brought to my attention. More or
lees Of tho trouble occurs in a number
OF orchards in that locality, consequent
ly it is n matter OF considerable interes.
to fruit growers everywhere. Some o,
the trees are dying. while there are
number OF dead limbs on others, but
the characteristic feature o. the disease
is tuft or rOse.te of small leaves at tho
end OF branches otherwise nearly bare
OF foliage. The similarity OF this condi
tion 10 the peach treo rosette-a COM
mon disease in portions OF the south
west-wag 70 great that the presence of
n new apple-tree disease was suspected.
| Visited this section in July and col
iected numerous specimens but no par
asitic organism could be detected by
laboratory Investigation
Much of the soil on the mesa contains
an excsSs Of mari and in many places
this substance forms n sp!id 'sNbitratem.
At the edge o. one orchard visited the
owner was digging and burning it TO
make a conent to hs used IN macon
work. The mari in itself is perhaps not
harmful to plants: in fact when Judic
iously applied to laud it acts as q liber-
ator OF plant food. but when present in
excess the soil is infertle. This is shown
by the fact that when roots penetrate
the mari subsiratum they send out few
or no forous rootlets. The roots do not
usually penetrate this substratum to
any extent, consequently thb trees are
often sh1llOw- rooted in orchards where
the layer of mari is close to the surface.
Tho level OF the lowest roots on one dy.
NJ tree was only ten inches below the
surface Of the soil. At this d,pth they
branched out horizontally, whero they
were readily injured by lack OF nloisture
and action Of frost.
A more immediate cause for tLis con
ditiou OF the tr, es is found 10 tho water
supply. Water lie plentiful du.ilg the
early part OF the season but in the latter
part OF June it is usually exhausted.
The Dature OF ths soil Is such that it
rsadiiy drieE out and iEs trees suffer for
moisture, consequently growth stops
and tho TISSUES harden. In the latter
pert o; July partial supply Of water is
again turned into the bitches and the
orchards are irrigated. The result is
that in many instances these trees make
a distinct second growth which is inmE-
iure when cold weather comes on.
Those branches which are not killed out
right but are severely injured duriug
the winter put forth feoble growth the
following spring. The end bud. usually
being the strongest. lives at the expense
Of the others. consequently many Of the
growth at all and the tsrminal one de
relop, contracted branch on which
the leaves are crowded, thus forming
tho rosettc.
The Eoeoad growth is not always noe
Cssary. however, Tor the appearance Of
this diseate. Shallow rooted trees plant.
ed in soil that is quickly dried ont are
easily i.iured during winter. This
probably accounts Tor the fact that the
discase hrst attracted general attention
after the hard wiute. Of ls9S ~. Onr
orchard was visited 10 which small
number OF dispasel branches had ap-
pesred. but which had baeu promptly
removed or ssr-Tely Gu; back early in
spring. In the fail tho tree, appeared
10 be perfectly healthy and bad IN lde
vigorous growth which showed no sign
OF disease. This tends TO ccutirm tho
conclusion that the difficulty rs due to
local conditions and not to a specific
organism which might spread 10 other
poriioss OF tho vailey.-FieId and Farm.