Tikka leaf spot (groundnut)
Groundnut’s major leaf spot — dark brown round spots (early and late) that shed the leaves before harvest and cut pod yield.
- Pathogen
- Fungi (Cercospora complex)
- Spreads by
- Wind & rain-splashed spores; debris
- Favoured by
- Warm, humid, wet weather
- Main risk
- Defoliation before harvest; low pod yield
Overview
Tikka is the common name for the leaf-spot disease complex of groundnut, caused by two related fungi that produce "early leaf spot" and "late leaf spot". It is the most important foliar disease of groundnut across India. It shows as small round to sub-circular dark brown to black spots on the leaflets, often with a yellow halo (more prominent in early leaf spot), and also on the petioles and stems.
The real damage is defoliation: as the spots multiply, especially in the second half of the crop, the leaves yellow and drop, and heavy tikka can strip the plant of most of its leaves before harvest. This cuts both pod yield (the plant cannot fill the pods without leaves) and the value of the haulm (fodder). Late leaf spot in particular defoliates severely near maturity. It is favoured by warm, humid, wet weather and carries over on infected groundnut debris and volunteers.
How to identify it
- Small round to sub-circular dark brown to black spots on the leaflets, often ringed by a yellow halo (clearer in early leaf spot).
- Spots also on the petioles and stems as the disease builds.
- Progressive yellowing and shedding of leaves — heavy tikka strips much of the foliage before harvest.
- Late leaf spot spots that are darker, more numerous underneath, and cause the worst defoliation near maturity.
What causes it and when
- The tikka fungi (early and late leaf spot), spread by wind- and rain-splashed spores and carried on infected groundnut debris and volunteers.
- Favoured by warm, humid, wet weather with leaf wetness — it builds through the crop and peaks in the second half.
- Worse with continuous groundnut cropping and where infected debris is left in the field.
- Late leaf spot generally appears later and causes the heaviest defoliation near maturity.
Cultural & organic control
- Grow resistant/tolerant varieties and rotate away from groundnut to break the disease cycle.
- Use clean seed and destroy infected groundnut debris and volunteer plants that carry the fungi over.
- Avoid over-dense stands, and manage for good airflow so the canopy dries.
- Treat seed and spray with recommended bio-agents where advised.
Chemical control
- Start protective sprays when spots first appear (often from around 30–40 days) and repeat on the recommended schedule, especially through the second half of the crop when defoliation is decided.
- CIB&RC-registered fungicides for tikka on groundnut (e.g. mancozeb, chlorothalonil and recommended systemics) are used and rotated to avoid resistance.
- Cover the foliage well, including the undersides, and observe the pre-harvest interval.
- Confirm the current spray schedule for your area with your local KVK/groundnut research station.
Prevent it coming back
- Use resistant varieties, clean seed and crop rotation, and destroy infected debris and volunteers.
- Protect the crop through the second half, when late leaf spot defoliates and pod fill happens.
- Manage density and airflow, and rotate fungicide groups across the season.
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 groundnut leaves have dark round spots and are dropping before harvest. What is it?
That is tikka — the leaf-spot disease of groundnut (early and late leaf spot). The dark brown to black round spots, often with a yellow halo, multiply and shed the leaves, so the plant loses much of its foliage before harvest. That defoliation cuts pod yield and haulm value. Use resistant varieties and rotation, and spray protectively from the first spots through the second half of the crop.
Why is defoliation the main problem with tikka?
Because a groundnut plant fills its pods using its leaves, and tikka’s dark spots make the leaves yellow and drop — especially late leaf spot near maturity. Once the plant loses most of its leaves it cannot fill the pods properly, so pod yield falls, and the leaf-and-stem haulm (valued as fodder) is worth less too. Keeping the foliage healthy through pod fill is the whole point of control.
When should I spray groundnut for tikka?
Start protective sprays when the first spots appear (often around 30–40 days after sowing) and continue on the recommended schedule, with particular attention to the second half of the crop when late leaf spot defoliates and the pods are filling. Use a registered fungicide, cover the leaves including the undersides, rotate groups, and observe the pre-harvest interval. Confirm the schedule with your KVK.
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.