Wheat import mixed blessing, hunt on for ‘invasive’ weeds

September 25, 2009

Agricultural scientists from ten states have embarked on a hunt to trace and isolate five harmful “invasive weeds” which made their way into the country through wheat imports. The Centre had imported a huge quantity of wheat for supply through the Public Distribution System to tide over a scarcity two years ago.

Surveillance officers are moving from village to village scanning backyards, compost pits and other places around godowns and fair price shops to locate the alien weeds Ambrosia trifida, Viola arvensis, Cenchrus tribuloids, Cynoglosum officinale and Carolinense. Plants of these foreign weeds have already been traced to Madhya Pradesh, Chhattisgarh, Gujarat, Orissa, Maharashtra, West Bengal, Tamil Nadu, Andhra Pradesh, Kerala and Karnataka, said Dr Jay G Varshney, Director of National Research Centre for Weed science. He told The Indian Express that the Centre had imported nearly 63 lakh metric tonnes of wheat in 2006-07 from Russia, Australia, Canada, Hungary, Europe, France, Argentina, Romania, Netherlands, Kazakhstan, and Bulgaria in which nearly 25 types of weed seeds were found.

“Initially, seeds of the relatively-unknown five invasive weeds were traced while we later intercepted nearly a dozen other species which came to India through this wheat import. We are not aware how these weeds could develop in our climatic conditions and how fast they could spread in our ecosystem. Besides, we have to study the possible effects on human and animal health”, he said adding that the Jabalpur-based Directorate of Weed Science Research has taken up a Rs 6.66 crore project for surveillance of these invasive weeds.

Varshney said once any of these alien species were detected, these plants would be grown under controlled conditions to study all their characteristics before taking up the project for their eradication. Such aggressive surveillance has become necessary as the fields in the country are already highly infested with weeds earlier introduced, namely Parthenium hysterophorus, which spreads epidemically in all seasons, he added.

According to Indira Gandhi Agriculture University (IGAU), Raipur, Director (Research services) Dr S S Shaw and Principal Scientist A P Singh, the spread of alien weed Ambrosia trifida could affect human health as it was suspected to contain allergic pollens.

After identification, he said, the weed plant would be sent to the Botanical Survey of India for approval before taking up studies on issues such as their suppression rate and control measures. Agriculture experts say that it was essential to control and check spread of such invasive weeds as they push native species to the verge of extinction and drastically reduce the yield of economic species and agriculture crops.

(Courtesy : Indian Express)