A concerted effort against weeds in cassava

Weeds are major constraints to the productivity of cassava with a negative impact on millions of African farmers that depend on the root crop for their livelihoods. Yield losses vary between 50 and 90% depending on the level of infestation in the fields.

Weeds are major constraints to the productivity of cassava with a negative impact on millions of African farmers that depend on the root crop for their livelihoods. Yield losses vary between 50 and 90% depending on the level of infestation in the fields.

In Nigeria, home to an annual production of about 54 million tons, the yield is less than 8 t/ha, which is paltry compared to cassava-producing countries in Asia such as India and Thailand where yields average more than 20 t/ha. Several studies point to poor control of weeds as a major contributor to this low yield performance in Nigeria and similar results across Africa. But beyond reducing yields, such infestation also undermines the health and social life of farmers, especially the women and children. Weeding is generally done manually using a hand hoe in Nigeria and is back-breaking work. Farmers, mostly the women, spend an average of 500 hours yearly weeding their cassava fields. And in many cases, children are drafted or pulled out of school to assist them.

The Cassava Weed Management Project to the rescue

To address the weed menace in cassava cropping systems, the Cassava Weed Management Project (CWMP) was conceived in 2014 with funding support from the Bill & Melinda Gates Foundation. The project aims to improve the agronomy of cassava, looking at practices such as tillage versus no tillage, cassava varieties, planting density, fertilization, and intercropping. Closely linked to agronomy is the identification and adaption of mechanical weed control methods. The project also screens environmentally friendly herbicides, evaluates their use, and integrates all the weed control options in one package. It builds the capacity of extension and spray service providers on implementing weed control measures while ensuring the equal participation of men and women in the process.

Women and children generally do the weeding— manually—in cassava fields in Nigeria.

Getting partners on board

Before its commencement in 2014, the project invited chemical companies such as Bayer AG, Syngenta, SaroAgroSciences, BASF, Valent, FMC, and Monsanto to a participatory planning meeting. The meeting sought the buy-in of the chemical companies for sustainability of the project’s interventions. Other partners that attended the pre-inception meeting were CropLife Nigeria, the National Agency for Food and Drug Administration and Control (NAFDAC), the Standards Organization of Nigeria (SON), the Federal Ministry of Agriculture and Rural Development (FMARD), and the National Environmental Standards and Regulation Enforcement Agency (NESREA). The meeting, among other things, drew up a list of candidate herbicides for screening in cassava farming systems. Because these companies were involved at the initial stage it became easier for them to take part in the subsequent training of extension workers and farmers in the safe use and handling of herbicides.

Weeding in cassava fields does not have to be a back-breaking chore!

During its first two years, the project conducted trials on agronomy and mechanical weeding, and screened more than 41 herbicides across three of the agroecological zones of Nigeria (derived savanna, southern Guinea savanna, and humid forest). The project worked with existing and new partners such as FMARD, cassava producer associations, agro-dealers, chemical companies, the Federal University of Agriculture at Makurdi, the Federal University of Agriculture Abeokuta, the National Root Crops Research Institute, NAFDAC, SON, Agricultural Development Programs, and Extension Service Providers, i.e., contract sprayers, (also referred to as spray service providers or SSPs). The project established synergistic links with other IITA-led projects such as the African Cassava Agronomy Initiative (ACAI) and the COMPRO II Project that similarly use partnerships to develop, commercialize, and diffuse agricultural products that increase crop yields.

CWMP: The journey so far

The initial partnerships established by the project with the signing of memoranda of understanding with the diverse stakeholders brought several benefits.

For instance, six companies provided herbicides free of charge for screening. In all, the project screened and analyzed herbicides of 41 different types under transparent and controlled conditions, leading to the selection of those best performing for on-farm demonstration. The involvement of regulatory agencies such as NAFDAC, NESREA, and SON enabled the easy shipment of the identified herbicides into Nigeria from abroad; this was also facilitated through IITA’s own Supply Chain Unit.

Year 3 of CWMP was a transition phase to on-farm trials but this time with researchers managing the trials and farmers playing an active role in observation and the mobilization of fellow farmers. The project recorded Weeding in cassava fields does not have to be a back-breaking chore! Photo by IITA. 51 success on this front. The collaboration with the ADPs, NRCRI, universities, and farmers was the key in establishing the trials and ensuring that they were safe from outbreaks of fire or attacks by cattle. This collective action that brought on-board SSPs and agro-dealers at the village level also helped pull in much-needed financial and in-kind resources from other stakeholders, thereby contributing towards the sustainability of the project’s initiatives.

In 2016, the project organized several farmers’ field days and other related activities. During these field days farmers were mobilized to participate, learn, and understand improved methods of cassava cultivation. The field activities also provided an opportunity to share knowledge on herbicide safety and other aspects of cassava production. In all, the project has directly reached 7121 farmers through its activities (2229 females and 4892 males).

During the same period, CWMP produced 13 project-related articles, which were shared with more than 200 journalists. The stories were also published in the project’s newsletter and website.The newsletters were shared with 3005 individuals via email; a limited number of copies were printed and handed to people in face-to-face meetings. The newsletter, Cassava Matters, has become a platform for sharing information not only of CWMP activities but also of ACAI and Building a Sustainable, Integrated Seed System for Cassava in Nigeria (BASICS).

Regarding its Web and social media presence, the project’s website (http://www.cassavaweed.org/) recorded 1851 downloads, while 21 documents and videos were uploaded. The CWMP Twitter account (CassavaWeedMgt) produced a total of 2080 tweets in 2016 and has 753 followers. The project’s Facebook page (https://www.facebook. com/cassava.weedmgt) has 728 followers and registered 710 likes Spray service providers undergoing practical training on knapsack calibration. Photo by IITA. 52 for the page (https://www.facebook.com/Sustainablecassavasystems). Its LinkedIn account (https://www.linkedin.com/in/cassava-weedmanagement-project) has 1,565 contacts. The project also has accounts on Slideshare (http://www.slideshare.net/CassavaWeed14), with 18 uploaded documents and 7962 views; on Pinterest with 5427 views; as well as on Flickr and Google+. The YouTube channel houses 10 videos, with a total of 760 views. A Facebook group was also created with 372 members by the end of 2016. Through social media, CWMP reached about 110,000 individuals.

The Project’s mobile WhatsApp application was a game changer for reaching farmers. We created a WhatsApp group also called Cassava Matters that has consistently been fully subscribed. The platform provides an interface in real time, connecting farmers with extension service providers, researchers, and processors, among others. Farmers are provided with information relating not only to weed control but also to other aspects of cassava cultivation. The platform currently has 256 members. The success of Cassava Matters is making other similar projects adopt the innovation.

ORCID: 0000-0001-6178-2606, 0000-0002-6329-7783, 0000-0002-6047-9821, 0000-0003-3601-5805

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