Solving Africa’s weed problem

Increasing crop production and improving farmers' lives

2 July 2009

By Leonard Gianessi & Alexander Rinkus, Croplife Foundation

As potential food shortages loom, donor, development and government agencies are assessing technologies and policies that promise to significantly increase food production in sub-Saharan Africa. Among these technologies are increased use of fertilizers, improved irrigation practices, advanced maize seeds, effective pest management systems, biotechnology … but not weed control.  

These organisations are ignoring an old problem for African farmers. Weed invasion should be adequately addressed if farmers are to attain optimal yields and gain the full value of additional use of fertilizer, irrigation and improved seeds. In any given year a small scale farmer can lose anywhere between a fifth and their full production due to uncontrollable weeds. In many cases entire fields are forced to be abandoned as the noxious plants grow and spiral out of control.

The cons of hand weeding

Currently, the primary method of weed control by smallholder farmers in Africa is hand weeding with short-handled tools. Preparing these fields for planting and weeding takes an enormous amount of time. A single hectare requires approximately 400 hours of labour for optimal weed control. With roughly one hundred million hectares of smallholder plots in Sub-Saharan Africa, this equates to forty billion hours a year spent by African women and children weeding fields by hand.

Not only is this a frightening amount of time in the field hand weeding, this is twenty billion hours spent in a bent double position. To weed just one hectare you would need to walk ten kilometers bent over at the waist ripping weeds out of the ground. As a result women in Africa are experiencing debilitating back problems at incredibly young ages. For the children, the time they spend in the field could have been spent in school but instead parents are forced to keep them at home in order to help with the weeding.

Even setting aside these basic health and human rights issues and focusing on the effectiveness of current practices it is clear that right now the forty billion hours of hand weeding are not even possible. There is simply not enough labour to complete the hours. The result is that weeds grow so prolifically that either not enough weeding is done or is done too late to prevent serious yield losses. The spraying of herbicides to remove weeds from African farm fields is a viable and proven technology which could be readily adopted with subsequent large increases in yield.

The pros of using herbicides

Herbicides have been tested for forty years in Africa and have been widely-adopted by large-scale commercial farmers but not by smallholders, who lack training in their use and ready access. Research has shown that, if smallholders used herbicides, there would be a 99% reduction in the hours required for weeding and it would take one-third the cost of hiring workers to pull weeds by hand. Farmers would have significantly more time available to plant and harvest additional crops, apply fertilizers, increase their income, and the children could attend school.

To address these constraints, CropLife Foundation (CLF) and CNFA, Inc. have launched a pilot project in Kenya and Malawi to demonstrate the feasibility and impact of the proper use of herbicides in expanding agricultural production, increasing efficiency and raising farm family incomes in Africa. A principal investigator is overseeing the plantings of maize, ground nuts and chick peas and the use of various herbicides, fungicides, seed treatments and post harvest protectants. Results of the field tests will be compiled and published later this year.

For more information go to CLF's website here or e-mail the author at arinkus@croplifefoundation.org

About CropLife Foundation

CropLife Foundation was created in 2001 to promote and advance sustainable agriculture and the environmentally sound use of crop protection products (pesticides) and bioengineered agriculture. Through sound science-based research and education, the organisation helps global agriculture economically produce safe, high quality, abundant food, fiber and other crops, thus ensuring food security and alleviating poverty, suffering and hardship.