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

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