Ascochyta blight (chickpea)
Brown lesions dotted with tiny dark pycnidia in rings, girdling stems and breaking the plant down — a fast, wet-weather chickpea blight.
- Pathogen
- Fungus (Ascochyta rabiei)
- Spreads by
- Seed, debris & rain-splashed spores
- Favoured by
- Cool, cloudy, wet, humid weather
- Main risk
- Stems girdled; plants collapse, field flattened
Overview
Ascochyta blight (Ascochyta rabiei) is one of the most destructive diseases of chickpea, especially where the crop grows through cool, cloudy, wet weather. It attacks all above-ground parts: leaves show brown, round-to-irregular lesions; stems and branches show elongated lesions; and all lesions typically carry tiny dark dots (pycnidia) arranged in concentric rings — a key diagnostic feature. Pods are also spotted, and the fungus can pass into the seed.
The most damaging effect is on the stems: girdling lesions break the stems and branches, so the plant snaps and collapses, and in a favourable spell the disease can spread through and flatten a whole field within days, appearing as rapidly-expanding dead, blighted patches. It is spread by infected seed, crop debris and rain-splash, and driven by cool, cloudy, wet, humid weather. Because it moves so fast, management is preventive: resistant varieties, clean/treated seed, debris and rotation, and a protective fungicide programme timed to wet spells.
How to identify it
- Brown, round-to-irregular lesions on leaves and elongated lesions on stems and branches.
- Tiny dark dots (pycnidia) arranged in concentric rings within the lesions — the key diagnostic sign.
- Girdling stem lesions that break the stems and branches, so the plant snaps and collapses.
- Rapidly-expanding dead, blighted patches in the field in a cool, cloudy, wet spell — a crop can flatten in days.
What causes it and when
- The fungus Ascochyta rabiei, spread by infected seed, crop debris and rain-splashed spores.
- Strongly favoured by cool, cloudy, wet, humid weather during the chickpea crop.
- The pycnidia in the lesions release spores that splash to new plants, so it spreads fast in the rain.
- Carries over on seed and debris, so infected seed and stubble start the next outbreak.
Cultural & organic control
- Grow resistant/tolerant varieties — the most important control in blight-prone areas.
- Use clean, certified, disease-free seed and treat the seed with a recommended fungicide.
- Rotate away from chickpea and destroy/deep-bury infected crop debris and stubble.
- Avoid very early, dense sowing in high-risk zones, and remove volunteer chickpea.
Chemical control
- Treat seed before sowing, then run a protective fungicide programme timed to cool, cloudy, wet spells when the blight moves.
- Use CIB&RC-registered fungicides for chickpea blight (e.g. mancozeb and recommended systemics), rotating groups.
- Because it spreads fast, act early on the first lesions and repeat as the weather stays favourable.
- Confirm the current spray programme and variety choice for your area with your local KVK.
Prevent it coming back
- Base the crop on resistant varieties, clean/treated seed and rotation with destruction of debris.
- Plan protective sprays in advance for cool, wet spells rather than reacting after the field blights.
- Avoid very early dense sowing in high-risk zones and remove volunteers and stubble.
Crops most at risk
Where this problem is called out in our crop guides — open a crop for the full package of practices.
Frequently asked questions
My chickpea plants have brown lesions with tiny dark dots in rings, and stems are breaking. What is it?
Brown lesions carrying tiny dark dots (pycnidia) in concentric rings on leaves, stems and pods, with girdling stem lesions that snap the plant, are Ascochyta blight (Ascochyta rabiei). In cool, cloudy, wet weather it spreads fast and can flatten a field in days. Grow a resistant variety, use clean/treated seed, rotate and destroy debris, and run a protective fungicide programme timed to wet spells — acting early on the first lesions.
Why can Ascochyta blight destroy a chickpea crop so quickly?
Because in cool, cloudy, wet weather the fungus multiplies fast — its lesions carry pycnidia that release spores which rain-splash to new plants — and because girdling stem lesions break the stems so whole plants collapse. Together, rapid spread plus stem breakage means a favourable wet spell can turn scattered lesions into flattened, dead patches across a field within days. That speed is why control has to be preventive and early: resistant varieties, clean seed, and protective sprays before the blight takes off.
How important is seed in Ascochyta blight?
Very — the fungus is seed-borne, so sowing infected seed introduces the disease directly into the crop and a new field, and it then spreads by rain-splash and survives on debris. Using clean, certified, disease-free seed and treating it with a recommended fungicide cuts off that route at the start. Combined with resistant varieties, rotation, debris destruction and a protective spray programme in wet weather, clean seed is a cornerstone of Ascochyta blight control.
Symptoms and control measures follow ICAR, KVK and state agricultural-university package-of-practices; any named chemical is a registered use. Always read the product label and confirm the dose for your crop and zone. editorial policy.