KAU Agri Infotech Portal

Onion (Allium cepa L.)

Anthracnose/ Smudge (Colletotrichum gloeosporiodes or Colletotrichum circinans)

Symptoms

The symptoms appear initially on the leaves as water soaked pale yellow spots, which spreads lengthwise covering entire leaf blade.
The affected leaves shrivel and droop down.
The disease also affects on scales of bulbs under field conditions and during storage.
The disease appears as dark green to almost black smudge (stroma of the fungus) on the bulb, neck or green leaves that are clinging to bulbs.
These smudges will be uniformly spread or arranged concentrically on the lessions.
The infection subsequently spread to the inner scales resulting in the complete rotting of the bulbs.

Management

Since the pathogen survives on crop debris, sanitation and destruction of infected crop debris helps in reducing the disease.
Use of resistant varieties
Seed treatment with Trichoderma viride or Pseudomonas fluorescens (20 g/litre of water/ kg of seeds).

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	20 g	400 g	1000 g	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	40 g	800 g	2000 g	Seed treatment
3	Thiram 75 WS	Hexathir, Tagithram, Thiram 75 DS, Thiride, Vegfru Thiram	Blue	4 gm/kg of seed	40 g	800 g	2000 g	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	-