“Maximum yield loss due to weeds”

Vice-Chancellor of TNAU P. Murugesa Boopathi (right) and T.M. Manjunath, Adviser, Agricultural Biotechnology, Monsanto, Bangalore (second from left), at a conference on weed management at the university in Coimbatore on Tuesday.  

Although there are many factors that cause reduction in yield, the maximum loss of 45 per cent is caused only by weeds, P. Murugesa Boopathi, Vice-Chancellor of Tamil Nadu Agricultural University, said here recently.

Inaugurating a conference on “Challenges in Weed Management in Agro-Ecosystems: Present Status and Future Strategies” at the university, he said there were instances in which weeds had caused 69 per cent yield loss in rice, 34 per cent in wheat, 50 per cent in pulses, 72 per cent in sugarcane and almost 90 per cent in vegetables.

“A large gap is noticed between the potential yield and the actual yield obtained. The total world food loss due to weeds is estimated to be 287 tonnes which accounts for 11.5 per cent of the total food production. There are about 30,000 plant species identified as weeds. Among these, 250 are listed as very troublesome,” the Vice-Chancellor said.

The bunchy top of banana virus disease had been carried by birds from Australia to India. The bird droppings had caused this disease to spread.

“Traditionally, weeds have been managed through cultural, physical and mechanical methods. Now, the awareness about the importance of Integrated Weed Management (IWM) systems, which comprises physical, chemical, cultural, and biotechnological methods, has increased,” Mr. Boopathi said.

T.M. Manjunath, Advisor, Agricultural Biotechnology, Monsanto, Bangalore, said invasive weeds were like terrorists and unless they were controlled, they could cause huge destruction. P. Subbian, Registrar of the university, said weeds caused an annual loss of Rs.30,000 crore in India alone. Owing to intensive agriculture and globalisation, weed infestation and invasiveness would increase in the coming years, he added.