Not all carrot diseases pests at first. These affecting the top growth directly will be immediately apparent, but it can be very disheartening to see what looks like a healthy crop of carrots growing happily in the garden and then dig them up and find the carrot rot all riddled with tunnels.
Carrots can be affected by the following plant pest–
1 Carrot fly
The adult fly is dark green to black in colour and measures about 4cm long. The maggots are slender, yellowish white in colour and measure about 6mm in length. The larvae feed on the roots and the young plants may be stunted or killed. The larvae make tunnels in the mature roots of carrot and parsnip, and render them unmarketable.
Apply diazinon 20EC @ 0.1% at the rate of 4litres/m2 or dimethoate 30EC @0.1% suspension @2 litres/m2 area. The suspension should be incorporated into the top 10cm soil. Diazinon granules are most effective when applied as a 25mm band 12-25 mm below the seed at the time of sowing.
carrot diseases pests with there control method
2. Willow-carrot aphid
The nymphs and adults suck the sap and cause damage. They transmit the carrot motley dwarf virus which products a yellow mottling of the leaves and stunting of the plants.
i) Spray dimethoate 30EC @ 1.5ml/litre of water or malathion 50EC @ 1.5ml/litre of water or oxydemeton methyl 25EC @ 1.25ml/litre of water with the appearance of the aphid. The spraying should be stopped 3 weeks before harvesting.
ii) Application of granular insecticides in the from of carbofuran, or phorate in the furrowa against carrot fly is also affective for preventing the aphid infestation.
Carrot con be affected by the flowing plant Disease-
1 Alternaria blight
Small dark brown to black spots develop along the leaf margin ‘carrot diseases pests’. The number of sports gradually increases and the interveinal tissues die. The whole leaflet dies and shrivels after sometime. The blackening and shrivelling progress is so rapid that the entire field exhibits frost injury in moist weather. In spite of the above foliage destruction the carrot roots are not affected in the field and in storage. The disease is seed borne and the pathogen also survive on the infected crop debris.
i) Treat seed with Captan or Thiram @ 3g/kg of ssed.
ii) Regular spraying of Dithane M-45@ 2g/litre of water at 7-10 days interval will control the disease.
2 Leaf spot
The chief symptom develop along the edges of the leaf margin in the form of elongated lesions. The infected leaflet shows lateral curling. Small pin pointed chlorotic spots develop in the middle of the leaf which soon turn into necrotic centre surrounded by a diffuse chlorotic border. The spots may coalesce to from bigger spots.
i) Treat seeds with Agrosan GN or Ceresan @ 2.5g/kg of ssed.
ii) Spray the crops with Dithane Z-78@ 2.5g/litre of water at 7-10 days interval in case of serious attack.
3 Powdery mildew
Charctertic white powdery spots of various sizes develop on the leaves, flowers, stems and fruits. Underneath this area the leaf may assume brown or purplish colour.
Spray Triphenyltin hydroxide (TPTH)@1.5g/litre of water or Morestan @ 1.5g/litre of waterwith the appearance of the disease.
4. Black rot
The fungi cause black sunken lesions, irregular to circular in outline. The decayed tissue is greenish black to jet black due to presence of masses of black spores. The disease affects roots in the field as well as in storage.
Seed borne inoculum can be controlled by Thiram soak treatment. For this the seeds are enclose in a mesh bag and immersed for 24 hours in a Thiram suspension (2g/litre water). About 10-20 litre of suspension will be sufficient for one kg of seed.
5 Storage rots
The fungi produce distinctive black sunken lesions with brown water soaked margins on the crowns and shanks of the roots.
Dip the roots in a suspension of Benomyl (0.5g/litre of water) before water.
6.Bacterial soft rot
This is a disease of storage and transit. The infected tissues soften and become watery or slime and the watery extrusion become evident as the rot progresses. A foul odour distinguishes it from the fungal rot. The bacterium lives in the soil and in the decaying refuse.
Avoid bruising on the carrot white handling during harvesting, grading or in transporting . Keep dry the root surface and store at 0 c and it 90% R.H.Thats the “carrot pests and diseases” management technic.