A Stem Bright of Fifed and Garden Peas 
7 
tion, and while it is difficult to reach any definite conclusions from 
dried material, I am inclined to believe that the Washington disease 
is different from that which occurs locally. 
DESCRIPTION OF THE DISEASE 
The disease can be recognized very readily by the watery, 
olive-green to olive-brown color of the stems, and by the yellowish, 
bruised and watery appearing stipules and leaflets. 
When the blight makes its appearance early in the season, 
before the plants are more than 8 to lo centimeters high (3 to 4 
inches), one usually finds the stand very uneven and scattering. It 
is not uncommon to see 4 to 6 feet of drill-row apparently without 
a single plant, but a closer examination of the ground will reveal 
the brown and withered remains of what were once small pea vines. 
Here and there may be located a few stragglers that have not yet 
succumbed; they usually have several dead leaves next to the 
ground, while above these are four or five that appear bruised, 
watery and often ochre-yellow in color. (Right-hand Egure in 
colored plate.) This leaf description applies particularly to the 
large, clasping stipules, the leaf-like structures at the base of the 
leaf stalk. (Left-hand figure in colored plate.) The stems of such 
plants are almost always dark-brown or black and considerably 
shrivelled, and so far as any further growth is concerned, they are 
practically dead. Occasionally one meets with a young plant of 
this kind in which the stem is black next to the ground, but above 
which both the stem and leaves are normal in color and look 
perfectly healthy. 
In older plants, say 12 to 15 centimeters high, (5 to 6 inches) 
where infection appears to have taken place at a later period, the 
stem is watery, olive-green to olive-brown in color (middle figure 
colored plate) ; the petioles of the leaves attached to the diseased 
portion soon become involved, turn watery, olive-green in color, 
seem to wilt or collapse and allow the leaves to droop; the leaf 
blades and stipules subsequently appear bruised and watery along 
the veins and mid-rib, which condition is communicated to the leaf 
tissue proper, and the whole leaf structure turns a watery, ochre- 
vellow color, wilts and dies, shrivelled and brown. 
So far as our present knowledge goes, the root and that part 
of the stem which is below ground are not affected. 
The infection starts in most cases from 2.5 to 3 centimeters 
(I to 1.25 inches) above the ground line and seems to move up 
the stem toward the growing tip. This is evident from the facts 
both that the discoloration on the lower part of the vine is nearly 
always darker than that higher up. indicating an older lesion, and 
that the loAver leaves are the first to die. 
