Phomopsis blight & fruit rot (brinjal)
Grey-brown patches on the leaves and stems, and soft rotting fruit that keeps spoiling in storage — a seed-borne fungus that follows brinjal from the nursery to the market crate.
- Pathogen
- Fungus (Phomopsis vexans)
- Spreads by
- Infected seed; wind and rain splash
- Favoured by
- Warm, humid weather; dense crop
- Main risk
- Fruit rot that spreads in storage
Overview
Phomopsis blight and fruit rot is caused by a fungus, Phomopsis vexans, that hides inside the seed of an infected plant. Because it starts inside the seed, it can show up on a crop grown from apparently healthy-looking seed if that seed lot was never properly treated. On leaves and stems it makes grey-brown spots and blighted patches; on the fruit it causes soft, sunken, rotting patches that keep spreading even after harvest, ruining fruit in storage or transport.
Warm, humid weather favours the fungus, and a crop grown too closely spaced with poor airflow stays damp longer and gets hit harder. Because the fungus travels with the seed, the single most useful thing a grower can do is start with properly treated, disease-free seed — spraying after the disease is already established only slows it down, it does not undo the seed-borne start.
How to identify it
- Grey-brown spots and blighted patches on leaves and stems, sometimes with tiny black dots (the fungus’s fruiting bodies) visible in older lesions.
- On fruit: soft, sunken, water-soaked patches that grow larger and turn the fruit mushy and rotten.
- Fruit rot often keeps spreading after harvest, so fruit that looked fine at picking can rot in the crate or basket a day or two later.
- A badly-hit crop shows blighted, ragged foliage alongside visibly rotting fruit on the plant and in storage.
What causes it and when
- A fungus, Phomopsis vexans, that is carried inside the seed of an infected plant — so it can enter a field through seed that looks perfectly normal.
- Once established, the fungus spreads further to healthy plants through wind and splashing rain.
- Warm, humid weather favours fast spread of both the leaf blight and the fruit rot.
- A closely-spaced, poorly-ventilated crop stays humid for longer, which favours the disease and makes it harder to control once it starts.
Cultural & organic control
- Always start with treated, disease-free seed from a reliable source — this is the most effective single step, since the disease travels with infected seed.
- Avoid overly close spacing so air can move through the crop and leaves dry faster after rain or dew.
- Remove and destroy visibly diseased fruit and badly blighted plant parts promptly instead of leaving them in the field.
- Rotate brinjal out of a field with a history of heavy Phomopsis blight for a season where land allows.
Chemical control
- Treat seed before sowing with a recommended fungicide to kill the fungus carried inside it.
- Spray a fungicide such as mancozeb or carbendazim at the first sign of leaf spots or fruit rot, and repeat at the recommended interval if humid weather continues.
- Handle picked fruit gently and cool it promptly, since bruised or overheated fruit rots faster even where the fungicide programme has been followed.
- Confirm the current recommended product and dose for your area with your local Krishi Vigyan Kendra (KVK).
Prevent it coming back
- Never save seed from a field that showed Phomopsis blight or fruit rot — always buy fresh, treated, certified seed instead.
- Keep the crop at recommended spacing and remove diseased debris promptly through the season.
- Rotate away from brinjal and other closely related crops on badly affected land for at least one 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 brinjal fruit looked fine at harvest but rotted a day later — why?
That is typical of Phomopsis fruit rot. The fungus can already be inside the fruit at picking, in the very early stages the eye cannot see, and it keeps spreading once the fruit is off the plant. Handling fruit gently and cooling it promptly slows this down, but the real fix is stopping the disease earlier in the season with treated seed and timely sprays.
Can I just use good seed from my own field next year?
Not if that field showed any Phomopsis blight or fruit rot — the fungus travels inside the seed, so saved seed from an infected crop can carry the disease straight into next year’s planting even if the seed looks normal. Buy fresh, treated, certified seed instead, especially after a season with this disease.
Is spraying enough to control this disease, or does seed treatment matter more?
Seed treatment matters more, because the fungus starts inside the seed before the plant even germinates. Sprays after the crop is growing help slow leaf blight and fruit rot, but they cannot undo an infection that started at the seed. Treated, certified seed plus timely sprays together give the best 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.