Belt Valley times. [volume] (Armington, Mont.) 1894-1977, 1925-03-12
Tomato Blight
Cause of Loss
Good Results Have Been
Obtained by Setting Out
Hardened Plants.

prepared By the United States Department
/ OF AEriculturel
tomato growers In the Middle At
lantic and Middle Western states may
greatly reduce their losses from leaf
spot or blight by following the prac-
tees recommended Ia Department Bull
letin l2SS, The Control OF Tomato
Leaf-Spot by Fred ]. Prltchard and
W. s Porte. recently issued by the
United States Department OF Agricul-
tune. The disease. which. In the
united States. causes the commercial
growers an estimated annual loss Of
10000 tons OF tomatoes, is widely dis
tributed east Of the Rocky mountains.
Because spore formation OF this
fungus takes place only az fempera-
lures between 50 and S0.5 degrees f.,
and because the disease develops best
only within temperature range OF
q to IS degrees f.. 1t is relatively
unlmportant In the northern states and
IN the far South. Because Il thrives
best In moist atmosphere, II Is more
abundant in Maryland. Virginia, and
the adjoining coast states than In the
inland parts OF the same temperature
belt.
Mixtures Too Expensive.
In the past bordeaux or other copper
pray mixtures have given the hest
control OF leaf-spot, but profits have
lot always been increased enough to
Justify the expense. The bulletin sug-
yests that more effective and eco
lomlca method Of control lies In the
Use OF modified field practices. Good
'esults have been obtained by setting
'ut large, st0cky. welI-hardened plants
'arly In the spring. Since the fungus
Ices not produce spores at low tenn
the disease will not begin
do damage In this region before the
after half OF June and for that rea-
on these early plants escape more
aaf-spot than the small ones that are
set late. Plants OF the de.
Irable kind ut least six weeks old can !
e produced cheaply outdoors In the
outh and shipped north at the right |
me for planting. In 1928 more than c
100000 southern-gr0wn tomato j
ants were shipped into Indiana and 0
considerable number into the East 0
n states. Some OF the larger north
n companies manufacturing tomato q
'oducts are growing their own plants o
the South. In order to obtain Il
'althy plants OF suitable size and v
e. The indlscrimlnate purchase OF Il
uthern stock OF unknown history g
mot be recommended. because Of p
e attendant danger Of introducing q
II and root-knot. There Is need OF Il
system Of plant certifcation to pro
t the eareful southern grower and 4
northern purchaser against this
niger
Fungus Prevented.
be fungus can be largely prevented ~
m 0ver-wintering by blowing under ~
old tomato vines in the fall The -
es must be thoroughly covered to ~
all the fungus on them and this 81
j be accomplished by first cutting ~
m with disk and by using a weed nl'
X on the pillow or weed hook and 'a''
tier. The fungus also grows and
duces spores on dead weeds, .ns
sses. and remains Of various crops, ~
scially cornstalks. BY keeping ~
" dead materials covered with soil ~
by destroying such plants as the .ns
Ieuettie, gr0undcherry. jInisonweed VIZ
nightshade and by burning dead
DIS and grasses along the fence w
: and other waste places. the dis sllil
can be we'll controlled. Don
Dpies Of the bulletin may be oh iAl'
ed free rs long AZ the supply lasts .ns
addressing the United State De per
ment Of Agriculture, Washington, pc