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1. Pests and Diseases of Oil
Crops
Oil crops Programme
KALRO NJORO
James Njoroge

2. Oil crops
The oil crops section at KALRO Njoro deals with
six crops
Soybean
Sunflower
Rapeseed
Safflower
Linseed
Castor

3. Activity
Germplasm maintenance
• Linseed
• Castor
• Safflower
• Rapeseed
Crop development
• Sunflower
• soybean

4. SUNFLOWER(Helianthus
annuus)
Introduction
• Use the cytoplasmic male sterility system (CMS)
A-line - The female line
B-line -The maintainer line
R-Line – The male line or restorer line
• Screening is done on parental material for
resistance to sunflower rust, Downey mildew
• Seed production involves all the three lines
• For seed production the A and R line are planted
in a ration of 3:1

5. Diseases of sunflower
Disease Symptoms Control measures
Steam and head
rot (Sclerotinia
wilt)
-White mycelia attack the root,
stem and head. Infected parts
shrink and rot.
-Crop rotation
-Use of certified seed
-Bury infected plants
Downey mildew -loose white mycelia found on
lower surface of the leaves
-Crop rotation
-Use of certified seed
- Use Redomil; Metaloxyl
White blister rust -White spore on lower surface
raised pale yellow portions in
upper leaf surface and stem
-Crop rotation
-Use of certified seed
- Use Redomil, Metaloxyl
Charcoal rot -Discolored stems at the base.
Internal stem appear shredded
-Crop rotation
-Use of certified seed
Yellow blotch
virus(Y.B.V)
-leaf yellowing, severe distortion
of leafs, buds and flower
-control the vector

6. Sunflower viral disease

7. Rot on sunflower

8. Sunflower pests
Pest Nature of damage Control measures
Cut worms Cut seedling at ground level Synthetic pyrethroids
African
bollworm
Larvae feed on leaves (Skeletonize
leaves), tunnel the heads
Alfix (alfacypermethrine)
Semi-loopers Old larvae feed on leaves Synthetic pyrethroids
Aphids Suck plant sap causing stunted
growth
Synthetic pyrethroids
Birds
Brimstone, canaries,
Grosbeak, weaver
Eat seeds Use bird scarers, plant same time

9. Bollworms on sunflower

10. Diseases of soybean
DISEASE SYMPTOMS CONTROL
Frog eye
leaf spot
-Appears about two months after planting
-Many round grey spots on leaves, stems and pods.
-spots have reddish brown margin that appears like a
frog’s eye. -Leaves drop prematurely
 Use certified seed
 Remove diseased plant
debris
 Use fungicides
Soybean
mosaic
virus
(SMV)
-Common disease in highlands
-Spread by aphids, seed or mechanically.
-Yellow vein clearing, mottled leaves , stunted
growth.
-Infected seeds appear mottled, hilum is bleeding
 Remove and destroy affected
plants.
 Use certified seed
 Control the vector
Bacteria
blight
-Common disease of soybean favoured by cool
weather.
-Small angular, water soaked lesions on leaves, pods
and stems
 Use certified seed
 Rotate soybean with non
legumes
 Do not cultivate when wet
Bacterial
pustule
-Disease develops in warm wet weather
-Small angular, yellowish green spots with dark
reddish brown centres without water soaked
margin on leaves. Dead areas may tear away.
 Use certified seed
 Seed treatment with copper
oxychloride + stretocycline
Purple
seed
stain/
blotch
•Infected seeds are pink to dark purple in colour.
•Infected seedlings turn dark purple and fall
prematurely
•Plow under crop residue
• crop rotation with cereals
• seed treatment with fungicides

11. Soybean mosaic virus
SMV on seeds

12. Purple seed stain

13. Soybean diseases
SMV on soybean SMV and Soybean rust on soybean

14. Stem canker on soybean

15. Pests of soybean
PEST HOW TO RECOGNIZE CONTROL
Semi loppers  Feed on young leaves leaving midribs
(skeletonized leaves).
 Use Decis, Bulldok star
Cut worms  Feed at night.
 Cuts young seedlings at the base of
stem
 Young caterpillars feed on foliage, older
ones cut stems.
 Synthetic pyrethroids
Coreid/stink
bugs
 Insects puncture pods and seeds and
suck sap.
 Results in shriveled seeds, lower
percent germination, small seed size,
lower seedling vigour and reduced
storage ability.
 Synthetic pyrethroids
Termites  Mmigratory insects common in
marginal areas.
 Feed on the tap roots.
 Destroy all the anthills
 Use a termiticide
(dragnet,granadiator)
African  Eat leaves and developing seeds. Synthetic pyrethroids

16. Bean bruchid on soybean

17. Diseases of canola
Disease symptom Control measures
Black leg Grey brown lesions on leaves,
black cankers on stem base
Crop rotation, bury crop
residues
White leaf spot Roundish whitish spot on leaves Crop rotation
Sclerotinia wilt Stem with white mycelia
Containing small black bodies
Crop rotation, use certified seed
and bury infected plants

18. Pests of canola
Pest Nature of damage Control methods
Cut worms Cut seedling at ground level Synthetic pyrethroids
Flea beetles Eat circular holes on leaves Synthetic pyrethroids
Saw flies/semi-loppers Skeletonize leaves Synthetic pyrethroids
Diamond back moth Eat underside of leaves Synthetic pyrethroids
African bollworm Larvae feeds on leaves and seed Synthetic pyrethroids
Aphids Suck plant sap causing stunted growth Synthetic pyrethroids
Birds Eat seed Use bird scarers.

19. Aphids on Canola