Minimizing Weed Losses: Path to Food Security

With the world’s population projected to reach 9.7 billion by 2050, ensuring a stable and sufficient food supply is of utmost importance.

Food security is a global challenge that affects millions of people worldwide. With the world’s population projected to reach 9.7 billion by 2050, ensuring a stable and sufficient food supply is of utmost importance. One critical aspect of achieving food security is minimizing losses in crop production caused by weeds. Weeds compete with crops for resources, reduce yields, and can even render an entire field unproductive. This study explores the significance of minimizing weed losses as a crucial step toward achieving global food security, supported by facts and figures.

Weeds are notorious pests in our agricultural system, costing 4.91 billion US dollars annually to the economy of Pakistan. Commonly, weeds are undesired plants growing out of their proper place.

Damage to weeds is not as visible as damage to other insects and pathogens, hence leaving them unnoticed by farmers. Their competition for resources like fertilisers, water, space, and solar radiation with crops results in reduced yield.

Weeds also lower the efficiency of tillage implements and irrigation systems due to physical hindrance. Many pathogens and insects utilise weeds as their alternate hosts and shelter houses. Dockage losses owing to the wiping out of weed seeds and their remains from final produce also bring down a farmer’s income.

Wheat is the most important food crop in Pakistan, where the average losses due to weeds are 6.7 million tonnes worth 2.23 billion USD. Bringing down losses caused by weeds to 50% can ensure food security in the country.

To fulfil the demands of an ever-expanding population, Pakistan has to import 2.6 million tonnes of wheat until the next harvest in April 2024. This quantity we need to import is less than half of that which is washed away by weeds.

Cotton is the largest exportable commodity in Pakistan. Climate change is directly hitting our cotton production system. A system that is already under pressure is more susceptible to damage from weeds. By minimising losses caused by weeds, we can secure another million bales worth 800 million USD.

The nation’s second exportable commodity is rice, in which weed losses cost 680 million USD by incurring average losses of about 2 million tonnes per year.

Weeds cost half a billion USD because they reduce sugarcane production by 20.5 million tons. In the case of maize, losses incurred by weeds ranked at the top, with average losses of about 35.5% costing about 590 million tons.

Considering the current average national yield of major crops, by reducing weed losses to 50%, we will be able to spare 3.6 million hectares of land, equivalent to 15% of our total cropped area. This area can be brought under other important crops like oil seeds and pulses, which will shrink our import bill.

The need for an effective weed control method has become more imperative under the current scenario of an expanding population and shrinking natural resources. The use of herbicides has been proven to be an efficient way of controlling weeds.

In Pakistan, herbicides only have 14% of the total pesticide market, which is the reverse case compared to the global market. In the global market, herbicides have a 47% share of the total pesticide market.

Despite being an effective way, a weedicide’s efficacy depends on various factors, like the method and time of application, dosage, and machinery used. Lack of awareness among farmers regarding the selection of suitable herbicides, their application time, and the proper method of application seems to be the major constraints in effective weed control.

Having little knowledge about the class or type of weeds present in the field leads to the selection of improper herbicides, which will not only provide poor weed control but will also damage the crop. Application of weed control operations at an improper stage will result in poor control or the re-emergence of weeds.

Faulty sprayer machines with inappropriate pressure and the use of improper nozzles result in the non-uniform application of chemicals. Training programmes for farmers should be arranged to educate them about the selection of suitable herbicides for the weeds present in their field. Further, region-wise mapping of weed flora should be carried out to make generalised recommendations.

Educating farmers regarding the proper method of applying herbicide, the calibration of the sprayer machine, the selection of a suitable nozzle (flood jet or flat fan), and the calculation of the required dose through demonstration should be followed by extension workers.

By adopting integrated weed management strategies, promoting sustainable agricultural practices, and fostering collaboration between the public and private sectors, we can mitigate the impact of weeds and work towards a world where everyone has access to an abundant and secure food supply.

Source: Economic Survey of Pakistan (2022–23), Ashiq and Atta (2014)

This article is jointly authored by Ahmad Jawad and Atif Naeem, serving as Scientific Officers in the Pakistan Agricultural Research Council (PARC).