KAU Agri Infotech Portal

Carrot (Daucus carota)

Alternaria blight (Alternaria dauci)

Symptoms

Alternaria leaf spots first appear at the margin of the leaflets as dark brown to black and irregular in shape.
Lesions produced on the petioles and stems are dark brown and often coalesce and girdle the stems.
As the disease progresses entire leaflets may shrivel and die, appearing scorched.
Alternaria leaf lesions are generally more prevalent on older foliage and plants.
The disease spreads rapidly on the older leaves of a maturing crop. This is due in part to poor air circulation among the older lower leaves in the canopy and to the moisture-holding capacity of the dense foliage.

Management

Follow crop rotation.
Remove and destroy the severely infected leaves and plant will minimize the disease infection.
Seed treatment with hot water at 50°C for 15 minutes is recommended.

Chemical Control

Sl.No	Generic Name	Trade Name	Color code	Dosage/litre	Knapsack Sprayer (Capacity 10L)	Recommendation		Remarks
Sl.No	Generic Name	Trade Name	Color code	Dosage/litre	Knapsack Sprayer (Capacity 10L)	Dosage/acre (200 L)	Dosage/hectare (500 L)	Remarks
1	Carbendazim 50 WP	Bavistin, Benfil, Bengard, Benlate, Benmain, Bensaan, Carben, Carziim50, Dhanustin, Dhanustin 50 WP, Fungiguard, Gancarzin50, Glizim, Mintho, Tagstin, Tiara, Zoom	Green	2 g/litre of water/kg of seed	-	-	-	Seed treatment
2	Mancozeb 75 WP	Devidayal M-45, Dhanuka M 45, Dhanuka M-45, Dithane, Dithane M-45, Hilthane, Hindustan M 45, Indofil M 45, Izeb M-45 Manzate, Luzen-45, Macoban, Macoban M-45, Mancosaan, Mancosaan M-45, Maneb Manzane, M-Guard, Savour M 45, Tata M-45 Eurofil-NT, Uthane M-45, Veera, Zinthane	Green	4 g/litre of water/kg of seed	-	-	-	Seed treatment
3	Thiram 75 WS	Hexathir, Tagithram, Thiram 75 DS, Thiride, Vegfru Thiram	Blue	4g/kg of seed	-	-	-	Seed treatment
4	Copper hydroxide 77 WP	HiDice, Kocide 101	Blue	1 g/litre of water	10 g	200 g	500 g	-
5	Copper oxychloride 50 WP	Bensaan, Blitox, Blue copper, Bluetrox, Copter, Cupramar, Cuprina, Dhanucop, Fytolan, Fytox, Fytran, Fytolan, Hilcopper, Killex copper, Maincop Dhanucop, Star cop, Tagcop, Trucop	Blue	2 g/litre of water	20 g	400 g	1000 g	-
6	Mancozeb 75 WP	Devidayal M-45, Dhanuka M 45, Dhanuka M-45, Dithane, Dithane M-45, Hilthane, Hindustan M 45, Indofil M 45, Izeb M-45 Manzate, Luzen-45, Macoban, Macoban M-45, Mancosaan, Mancosaan M-45, Maneb Manzane, M-Guard, Savour M 45, Tata M-45 Eurofil-NT, Uthane M-45, Veera, Zinthane	Green	3 g/litre of water	30 g	600 g	1500 g	-
7	Carbendazim 50 WP	Bavistin, Benfil, Bengard, Benlate, Benmain, Bensaan, Carben, Carziim50, Dhanustin, Dhanustin 50 WP, Fungiguard, Gancarzin50, Glizim, Mintho, Tagstin, Tiara, Zoom	Green	1 g/litre of water	10 g	200 g	500 g	-