Common leaf spot
Identification tip:
Leaves of infected plants are covered with small brown-to-black
spots.
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Common leaf spot
Identification tip:
Infected leaves have raised fruiting bodies in the middle of
brown leaf lesions.
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Downy mildew
Identification tip: Infected leaves are spotted with
a distinctive pale-green color.
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Downy mildew
Identification tip: Blotches on the upper sides of
infected leaves are gray-green to tan.
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Phytophthora root and crown rot
Identification tip:
Leaves
of infected plants turn yellow or tan and drop. Phytophthora can
infect large areas of alfalfa in a field.
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Phytophthora root and crown rot
Identification tip:
Red-orange-to-yellow streaks spread up from infected root
tips.
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Spring black stem
Identification tip: Small black spots cover leaves
and stems of infected plants.
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Spring black stem
Identification tip: Spring black stem lesions often
extend to the petiole.
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Stemphylium leafspot
Identification tip: Infected leaves are speckled with
light spots.
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Stemphylium leafspot
Identification tip: Infected leaves develop dry, brownish
lesions bordered by a dark ring.
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Stem nematode
Identification tip:
Look
for flagging alfalfa leaves.
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Stem nematode
Identification tip:
Damaged
plant showing dead stem buds, stunted shoots, and swollen
internodes.
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