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The gajar ghas invasion: from US wheat to India's fields

The gajar ghas invasion: from US wheat to India's fields
From US wheat to India’s fields: How ‘gajar ghas’ became an invasive weed nightmare · businesstoday.in

Many years ago, India did not have enough food for everyone.

The United States sent wheat to help, as part of a food-aid programme.

Hiding inside that wheat were tiny seeds of a plant called Parthenium, known in India as 'gajar ghas.'

When the wheat was used, the seeds fell into the ground and started to grow.

The plant grows very fast and makes thousands of seeds, so it spreads everywhere — roadsides, railway tracks and farm fields.

Scientists at ICAR say the weed has now taken over about 35 million hectares of land in India.

The weed is a problem because it takes space and food from crops and other plants.

It can also make people sick with rashes and allergies when they touch it.

India has tried pulling it out, using weed-killer sprays and bringing in a beetle from Mexico that eats the plant, but the weed is still very hard to get rid of.

Key facts

Weed
Parthenium (gajar ghas)
How introduced
Seeds carried in wheat shipped under the US food-aid programme
Area invaded
About 35 million hectares (ICAR estimate)
Regions affected
Across India, including Andaman and Nicobar Islands and Lakshadweep
Seed production
Thousands to tens of thousands of seeds per plant
Health effects
Skin irritation, dermatitis, respiratory and allergic problems; animals also affected
Control methods tried
Manual removal, herbicides and biological control
Biological control agent
Zygogramma bicolorata, a leaf-feeding beetle introduced from Mexico

Sources

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