Losses from stem rot were less serious in the last ) or 5 years 
than in the first part of the 10-year period. The improvement .is 
probably the result of improved rotation, fertilizer, and other 
cultural practices as well as of the normal variation in severity 
of the disease. However, each year there are fields where stem 
rot causes heavy losses. A conservative estimate for the 10-year 
period would be about 0.1 percent per year. 
Reduction of the milling quality and lowering of the grade caused 
by discolored kernels infected by fungi, stem rot, kernel smut, and 
white tip: are probably responsible for a reduction of 0.5 percent in 
the value of the rice crop each year, 
Peanuts 
Most of the losses to peanuts are from two diseases. The more com= 
mon disease is Cercospora leaf spot, which is very damaging to the 
leaves and thus weakens the plants. Another fungus disease, southern 
blight, attacks the roots, stems, and pods. Minor loss is caused by 
root-knot nematodes. These diseases are prevalent wherever peanuts 
are grown. 
Losses from Cercospora leaf spot can be reduced by dusting the 
plants with sulfur, but there is no control for southern blight and 
root-knot nematodes except crop rotation. 
Sorghum (including grain sorghum, sorgo, broom corn) 
Of the numerous diseases to which sorghum is subject, some of which 
frequently cause heavy losses, four general types may be recognized = 
(1) those that reduce stands by rotting the seed or by killing the 
seedlings; (2) those that attack the leaves and decrease the value of 
the plants for forage; (3) those that attack only the heads and pre- 
vent the normal formation of grain; and (lh) those that cause root or 
stalk rots and prevent the normal development and maturity of the 
entire plant. The loss from all diseases is estimated at 8.3 percent. 
The smts, which destroy the seeds, cause a reduction in the grain | 
yield of grain sorghums directly proportional to the amount of in- 
fection, but in sorgo they reduce the yield of forage or sirup only 
slightly. In broomcorn, smut may not affect the yield of fiber, but 
if it is abundant it blackens the brush and lowers its market value. 
Leaf diseases are prevalent in most sorghum-growing areas. They 
cause less reduction in the yield of grain sorghum, but they may 
seriously impair the production of forage from sorgo in the Gulf 
and Atlantic Coastal Plains and other humid regions, or in years of 
heavy rainfall. 
Seed rot is most severe when the soil is cold and wet after planting. 
It is common in the North and also elsewhere when seed is planted early. 
Much of the seed fails to germinate and rots because it is attacked 
by various seed-borne and soil-inhabiting fungi. 
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