University of nairobi visit
Transcript of University of nairobi visit
Pests and Diseases of Oil Crops
Oil crops ProgrammeKALRO NJOROJames Njoroge
Oil crops The oil crops section at KALRO Njoro deals with
six crops SoybeanSunflowerRapeseedSafflowerLinseedCastor
Activity
Germplasm maintenance• Linseed• Castor• Safflower• Rapeseed Crop development• Sunflower• soybean
SUNFLOWER(Helianthus annuus)
Introduction• Use the cytoplasmic male sterility system
(CMS)A-line - The female lineB-line -The maintainer lineR-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
Diseases of sunflowerDisease 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
Sunflower viral disease
Rot on sunflower
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
BirdsBrimstone, canaries, Grosbeak, weaver
Eat seeds Use bird scarers, plant same time
Bollworms on sunflower
Diseases of soybeanDISEAS
ESYMPTOMS 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
wetBacterial 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
Soybean mosaic virus
SMV on seeds
Purple seed stain
Soybean diseases
SMV on soybean SMV and Soybean rust on soybean
Stem canker on soybean
Pests of soybeanPEST 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 bollworm
Eat leaves and developing seeds. Synthetic pyrethroids
Birds
Bean bruchid on soybean
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
Pests of canolaPest 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
AphidsSuck plant sap causing stunted growth Synthetic pyrethroids
Birds Eat seed Use bird scarers.
Aphids on Canola
THANKYOU