ĐỀ THAM KHẢO KÌ THI TUYỂN SINH VÀO LỚP 10 MÔN TIẾNG ANH FORM 50 CÂU TRẮC NGHI...
Beet root diseases A lecture on ToT training of FFS By Mr Allah Dad Khan Provincial Coordinator IPM KPK MINFAL Islamabad
1.
2. Beet root Diseases
A
Lecture To ToT trainees (
FFS)
By
Mr. Allah Dad Khan
Provincial Coordinator IPM
KPK
MINFAL Pakistan
3.
4.
5. Cercospora leaf spot
Cercospora beticola
Symptoms
Brown to gray flecks or
spots surrounded by red-
purple halos on leaves;
yellow or brown necrotic
leaves
Cause
Fungus
8. Downy mildew
Peronospora farinosa
Symptoms
Plant leaves appear lighter
green; small, puckered,
thickened leaves; fuzzy gray
growth on both leaf surfaces
Cause
Fungus
Comments
Fungus survives in crop
residues over winter to infect
new crop.
Management
Plant resistant varieties
9. Damping off
Rhizoctonia solani
Phoma betae
Pythium ultimum
Aphanomyces cochlioides
Symptoms
Seedlings collapsing; blackened
roots; constriction of plant
crown
Cause
Fungi
Comments
Warm, wet weather favors
disease emergence; beet very
susceptible
Management
Treat seeds with fungicide prior
to planting; plant in well draining
soil; do not plant until soil is
sufficiently warm
10. Scab
Streptomyces scabies
Symptoms
Small round spots on roots that
enlarge, turn brown and rupture the
epidermis; raised corky spots on
root surface that are gray, white or
tan in color
Cause
Bacterium
Comments
Bacteria survive in soil; disease
emergence favors dry conditions
Management
Do not plant in soil know to be
infected; avoid crop rotation with
potato
11. Root knot nematode
Meloidogyne spp.
Symptoms
Galls on roots which can be
up to 3.3 cm (1 in) in diameter
but are usually smaller;
reduction in plant vigor;
yellowing plants which wilt in
hot weather
Cause
Nematode
Comments
Galls can appear as quickly as
a month prior to planting;
nematodes prefer sandy soils
and damage in areas of field
or garden with this type of soil
is most likely