Senji (sweet clover, Melilotus)
A winter legume weed of wheat, gram and mustard with clover-like leaves whose seed can taint wheat flour if it contaminates the grain.
- Type
- Broadleaf weed (annual legume, winter)
- Life cycle
- Annual; prolific seed
- Spreads by
- Seed; contaminates wheat grain
- Main harm
- Competes in rabi crops; can taint wheat flour
Overview
Senji (Melilotus alba, M. indica; sweet clover) is a common winter (rabi) broadleaf weed of wheat, gram, mustard and berseem in the plains. It is a fast-growing annual legume with clover-like trifoliate (three-leaflet) leaves, toothed leaflet margins, and small white or yellow flowers in slender spikes; the plant has a characteristic sweetish smell when crushed. It competes with the crop for nitrogen (being a legume it is less nitrogen-dependent, so it thrives), water, light and space.
A particular concern is that its small seed can contaminate wheat grain, and sweet clover contains a compound that can taint the flour and give an off-flavour, so a badly infested wheat crop can suffer a quality problem, not just yield loss. It also seeds prolifically and builds a seed bank. Management combines clean, senji-free seed, a competitive crop, timely broadleaf herbicides, and preventing seed set — plus not letting it into the grain.
How to identify it
- A fast-growing winter annual legume with clover-like trifoliate (three-leaflet) leaves and toothed leaflet margins.
- Small white or yellow flowers borne in slender spikes.
- A characteristic sweetish smell when the plant is crushed.
- Common in wheat, gram, mustard and berseem in the cooler season.
Why it is a problem
- Competes with the crop for water, light and space, and as a legume thrives even where nitrogen is limiting.
- Its seed can contaminate wheat grain, and sweet clover can taint the flour and give an off-flavour — a quality problem.
- Seeds prolifically and builds a soil seed bank, returning each cooler season.
- Spreads to new fields as a contaminant in crop seed.
Cultural & preventive control
- Use clean, senji-free certified crop seed — a major way it spreads is contaminated seed.
- Grow a competitive, well-fertilised, properly-spaced crop that shades the ground.
- Inter-cultivate/hoe early to remove senji while the crop is young, before it competes and seeds.
- Prevent seed set and keep it out of the harvested grain to protect quality and run down the seed bank.
Herbicide control
- Use recommended post-emergence broadleaf herbicides for the crop (e.g. 2,4-D or metsulfuron in wheat) at the correct early stage and dose.
- Time and choose the herbicide for the crop (a broadleaf herbicide safe in wheat is not the same as one for gram/mustard).
- Never tank-mix incompatible products, and follow label timing and rates.
- Confirm the current recommended broadleaf herbicide for your crop with your local KVK.
Integrated management
- Combine clean seed, a competitive crop, early inter-cultivation and timely broadleaf herbicides.
- Prevent seed set and keep senji out of the grain, both to run down the seed bank and to protect wheat quality.
- Rotate herbicide types and pair with cultural methods for durable control.
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
Which clover-like weed with a sweet smell is growing in my wheat?
A fast-growing winter legume with clover-like trifoliate (three-leaflet) toothed leaves, small white or yellow flowers in slender spikes, and a sweetish smell when crushed is senji (Melilotus, sweet clover). It competes with the crop and its seed can taint wheat flour. Use clean, senji-free seed, a competitive crop and early inter-cultivation, apply a recommended broadleaf herbicide (e.g. 2,4-D or metsulfuron in wheat) at the right stage, and keep it out of the harvested grain.
Why can senji spoil the quality of my wheat, not just the yield?
Because sweet clover (senji) contains a compound with an off-flavour, and its small seed can end up mixed in with the wheat grain at harvest. If enough senji seed contaminates the grain, it can taint the flour and give it an off-taste, so a badly infested wheat crop suffers a quality and marketability problem on top of the yield loss from competition. That is why it is important both to control senji in the field and to keep its seed out of the harvested grain.
How does clean seed help against senji?
One of the main ways senji spreads to new fields is as a contaminant in the crop seed you sow, because its seed can travel mixed with wheat or fodder-legume seed. Sowing clean, certified, senji-free seed cuts off that route at the start. Combined with a competitive crop, early inter-cultivation, timely broadleaf herbicides and preventing seed set, clean seed is a cornerstone of keeping senji out and running it down where it already occurs.
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.