Silent invader

A highly invasive weed of foreign origin is spreading across north India and it could threaten the country’s food security

- REKHA DIXIT

THERE IS AN EMERGING weed problem in north India. No, this one is not star-spangled like the one currently being exposed in Bollywood. The ramifications, however, could be much worse, as it could threaten India’s food security.

Two studies in the recent years have flagged the emergence and spread of a hitherto lesser known plant, Emex australis, across the wheat fields of Haryana and west Uttar Pradesh. Both studies warn that, if left ignored, this plant could take over the fields and reduce crop yield.

To the untrained eye, E. australis looks like a cousin of the spinach. In fact, in South Africa, where it is a native, its leaves are sometimes used as a vegetable. It is a sturdy plant which establishes itself in thick clusters and can deplete a field of nutrients meant for the crop. The weed has already spread across Australia, edging out both wheat and the sweet pasture grass. Known by various common names like cat’s head, bull head, devil’s thorn, spiny emex and goat head, this weed produces fruits called achene, which have three sharp spines, giving the plant yet another moniker, the three-cornered jack. In pasture lands, these spines can injure grazing cattle. Extremely resilient, the spines attach themselves to tractor tyres, shoes and even bare feet, and thus spread from field to field. They can even float on water, thus furthering the range.