FAISALABAD, March 19: University of Agriculture vice-chancellor Dr Bashir Ahmad has said weeds decrease crop yield from 25 per cent to 30 per cent and unrestrained weed growth may even cause complete crop failure.

He was addressing the opening session of a three-day international workshop on ‘Allelopathy’ which started here on Monday.

Dr Ahmad expressed concern over billions of rupees loss to the national exchequer per annum due to lack of weed control. He suggested developing weed management strategies which were effective economically, practically flexible and environmentally feasible.

Stressing the need of vertical expansion he said the scope of horizontal expansion in agriculture was limited. “The only option left is to focus on vertical expansion by increasing yield of important crops like wheat, cotton, sugarcane and oilseeds.”

The VC said agriculture was the backbone of country’s economy but the extensive fluctuation in its growth has greatly influenced national economy. He termed the sixties a period of green revolution when average growth rate rose by 5.1 per cent.

He said the production of horticultural crops has been diminishing and if proper weed management practices were not followed, it would fall further.

Dr Ahmad said though the Allelopathy was a relatively new science, its acceptance as alternative to pesticides has now been realised worldwide.

He said the Allelopathy might help reduce the use of chemicals, a WTO requirement, so that Pakistani produce got place in international market.

Earlier, International Allelopathy Society president Yoshiharu Fujii introduced the science of Allelopathy and said this was the way to reduce agro-chemical like herbicides, insecticide, fungicide and nematocides as it helps increase yield to a most advantageous level.