Weed in the crop field is a real hazard that reduces the yield of food nay all crops per hectare. Crop field's weed competes with crops for light, nutrients and water thereby resulting in yield loss of crops up to 80-90 per cent in worst cases. Experts said that provided proper weed management, yields of food crops in the country can potentially be increased up to 22 per cent. In the words of the Bangladesh Rice Research Institute's (BRRI) experts, "Proper implementations of eco-friendly, sustainable and integrated weed management in crop fields can increase 18-22 per cent yield at the national level, which can contribute to total food production of Bangladesh". Similar is the case with the country's other crops also.
Improper weeding in Bangladesh causes crop yield loss that ranges between 40 and 50 per cent in rice, 24 to 58 per cent in wheat, almost 49 per cent in maize, 43 per cent in potato, 20 per cent in sugarcane, 75-80 per cent in jute, nine per cent in tea and 25 to 60 per cent in other crops. The Bangladeshi farmers in current practice usually do weeding by hand hoe, a mechanical weeding-hook and chemical weeding with herbicide. Hand weeding in field crops is costly. The practice needs more money and it is time consuming. Mechanical weed control is not so much popular in the country due to its unavailability and effectiveness. In case of hand weeding, depending on crops, it needs Tk 10,000 to Tk. 18,000 per hectare.
The farmers are now more interested in chemical weed control with herbicide. The herbicide adoption is increasing day by day due to its quick effectiveness and low cost. But improper herbicide application may cause environmental hazards and may disturb field ecosystem. From different research reports in this regard it was observed that crop yield could be increased significantly if proper weed management could be done in an integrated approach. So now the time is ripe about developing innovative approaches, economic and eco-friendly weed management technologies to address challenges ahead for sustainable agriculture and other social benefits.
The experts opine that in future emphasis should be given to mechanical and biological weed control. Researchers concluded that low cost weed control measures should be adopted to increase economic gain from crop fields. However, herbicide should be applied in proper time and dose and advanced level research should be carried out about the impact of different groups of herbicide on the crop-soil-system. At the present stage, in this agricultural land-scarce country, a future research programme needs to be undertaken for eco-friendly and sustainable weed management practices that will impact total food production and sustainable development goals in Bangladesh.
The writer is a former Staff Economist, Pakistan Institute of Development Economics, Karachi, Staff Reporter of now-defunct Morning News, Dhaka, Deputy Field Surveillance Supervisor, ISRT, DU. and retired Professor of Economics and Vice Principal of Cumilla Government Women's College, Cumilla.