Weeds in crop fields are a real hazard that reduces the yield. In a field, weeds compete with the crops for light, nutrients and water causing the loss of yield up to 80-90 per cent in worst cases. Experts said on May 12 last at the 6th conference of the Weed Science Society of Bangladesh (WSSB) at the Bangladesh Rice Research Institute (BRRI) in Gazipur that proper weed management could increase the yield of food crops in the country up to 22 per cent. In the words of the BRRI, "Proper implementation of eco-friendly, sustainable and integrated weed management in paddy fields can increase the yield by 18-22 per cent at the national level, which can contribute to total food production of Bangladesh." Similar is the case with other crops also.
Improper weeding in Bangladesh causes yield losses ranging between 40 per cent and 50 per cent of rice, 24 to 58 per cent of wheat, almost 49 per cent of maize, 43 per cent of potato, 20 per cent of sugarcane, 75-80 per cent of jute, nine per cent of tea and 25 to 60 per cent of other crops.
As far as the current practices rea concerned, the Bangladeshi farmers usually weed their fields by hand, hoe or mechanical weeding-hook. They also resort to chemical weeding with herbicide. Weeding any field by hand is costly. The practice involves more money and it is time-consuming. Mechanical weed control is not so much popular due to unavailability of necessary equipment and less effectiveness. Weeding any field by hand costs Tk 10,000 to 18,000 per hectare depending on crops.
The farmers are now more interested in chemical weed control using the herbicide technique. 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 the field ecosystem. In the WSSB 6th conference about 19 scientific papers from different research organisations were presented. The research papers made it clear that crop yield could be increased significantly, if proper weed management is done in an integrated approach. So, now the time is ripe about developing innovative approaches and adopting economic and eco-friendly weed management technologies to address challenges lying ahead for sustainable agriculture and other social benefits.
The experts opine that in the future emphasis should be laid on mechanical and biological weed control. Researchers concluded that low cost weed control measures should be adopted to increase the economic gain from crop fields. However, herbicide should be applied in the proper time and dose and advanced-level research should be carried out on the impact of different groups of herbicides in 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 the total food production and achievement of sustainable development goals (SDGs) in Bangladesh.
The writer is a retired Professor of Economics, BCS General Education Cadre.
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