Foxtail millet blast
Spindle leaf spots, a black rot on the neck below the ear, and poorly filled heads тАФ a fungus driven by humid, cloudy weather at flowering and by excess nitrogen.
- Pathogen
- Fungus (Pyricularia setariae)
- Spreads by
- Air-borne spores; seed, stubble & grasses
- Favoured by
- Humid cloudy weather at flowering, excess N
- Main risk
- Choked grain fill; empty ears
Overview
Blast, caused by the fungus Pyricularia setariae, is the most important disease of foxtail millet (kangni). It appears in three phases. Leaf blast makes spindle- or diamond-shaped spots with a grey centre and a brown border, which merge and dry the leaf. Neck blast is a black, shrivelled, often broken zone on the stalk just below the ear head. Head blast darkens the grain head itself so it fills poorly or not at all.
Neck and head blast are the phases that cost yield, because they cut off grain filling directly and can empty the ear. The disease is favoured by long humid, overcast, drizzly weather at ear emergence and flowering, a dense over-fertilised canopy, and heavy nitrogen. It is seed-borne and also carries over on infected stubble and grasses. Management combines a resistant variety (such as SiA 3085), treated seed, moderate nitrogen and a fungicide timed to the boot-to-ear stage when blast weather sets in.
How to identify it
- Leaf blast: spindle- or diamond-shaped spots, grey centre with a brown border, merging so the leaf dries.
- Neck blast: a black, shrivelled, weak zone on the stalk just below the ear head тАФ the ear may snap or hang.
- Head blast: a darkened grain head with poorly filled or empty grain.
- Worst after a spell of humid, cloudy, drizzly weather at flowering, and in a lush, heavily fertilised crop.
What causes it and when
- The fungus Pyricularia setariae, spread by air-borne spores and carried over on infected seed, stubble and grasses.
- Favoured by long leaf-wetness and dew, overcast humid weather at ear emergence and grain set, a dense canopy and heavy nitrogen.
- Leaf blast can show from tillering; neck and head blast strike from ear emergence through grain fill.
Cultural & organic control
- Grow a blast-resistant variety тАФ the most reliable defence (SiA 3085 is documented as resistant to blast and downy mildew).
- Treat seed with carbendazim or a Trichoderma formulation against seed-borne blast before sowing.
- Keep nitrogen moderate and split; avoid a heavy single dose that makes the crop lush.
- Sow a thin, even, correctly spaced stand so the canopy is open and airy, keep the field drained, and destroy infected stubble and volunteer grasses after harvest.
Chemical control
- Spray a recommended fungicide (tricyclazole, or a carbendazim/mancozeb combination) at the boot-leaf to ear-emergence stage when humid, cloudy blast weather sets in.
- Repeat once at flowering if the weather stays wet, to protect the neck and the grain head.
- A protective spray timed to the weather is far cheaper than the yield lost waiting for black necks to appear.
- Confirm the current product, dose and timing for your area with your KVK.
Prevent it coming back
- Base the crop on a resistant variety, treated seed and moderate, split nitrogen.
- Plan the boot-to-ear protective spray in advance where blast is regular, rather than reacting after the necks rot.
- Rotate foxtail millet with a non-host crop on a badly hit field, and clear infected stubble and field-edge grasses.
Crops most at risk
Where this problem is called out in our crop guides тАФ open a crop for the full package of practices.
Frequently asked questions
My kangni has black, shrivelled stalks just below the ear. What is it?
That is neck blast, the most damaging phase of foxtail millet blast. A black rot girdles the stalk just below the ear head, so grain filling is choked off and the ear may hang or snap. There is no cure for an affected ear тАФ protect the rest of the crop with a recommended fungicide at ear emergence and flowering, and grow a resistant variety such as SiA 3085 next season.
How do I prevent blast in foxtail millet?
Grow a blast-resistant variety such as SiA 3085, treat the seed with a fungicide before sowing, keep nitrogen moderate and split rather than heavy, sow a thin open stand, and keep the field drained. Where humid, cloudy weather sets in around flowering, spray a recommended fungicide (tricyclazole) at the boot-to-ear stage before symptoms appear.
Is foxtail millet blast the same as rice or finger millet blast?
They are caused by very closely related fungi in the Pyricularia / Magnaporthe group, and the leaf symptoms look similar, but they are treated as separate diseases on separate hosts (foxtail millet blast is Pyricularia setariae). The management principles тАФ resistant variety, treated seed, moderate nitrogen, timed protective fungicide тАФ are the same.
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.