Breeding improved cassava varieties that women and men want

Breeding improved cassava varieties that women and men want

Understanding gender differences in trait preferences for cassava can accelerate adoption as this knowledge is incorporated into breeding programs.

Cassava is the daily bread of Nigeria, but it is hardly ever simply boiled and eaten. Nigerian cassava is processed into products like gari (toasted cassava starch granules), which are made in villages and trucked to cities across the country. Processing usually involves several different steps and quite a lot of work. While women do grow cassava, they also provide most of the labor for cassava processing, both for food products to eat at home and in many cases, to make a living from small-scale enterprises. Men grow larger cassava farms than women and prefer to sell cassava as fresh roots, instead of processing it. Because of these varying roles, women and men’s perception of the most critical traits needed in cassava may differ. 

The Next Generation Cassava Breeding (NextGen) project aims to take these traits into account to improve targeting of cassava varieties for end users.  Nextgen uses a new approach to accelerate breeding called genomic selection that relies on statistical modeling to predict cassava performance before field-testing.

Hale Ann Tufan of Cornell University leads the survey component of Nextgen. She explains, “We need to think like a company. Companies have to build consumer profiles of their users and then develop typologies around these to inform the breeding program.” Likewise, plant breeders need to understand how important a trait is for farmers, as not all the traits that farmers list are equally important.

A joint study by the International Institute of Tropical Agriculture (IITA) and the National Root Crops Research Institute (NRCRI) in eight communities in Southwest and Southeast Nigeria was supported by NextGen. It used focus group discussions and individual interviews to assess differences in trait and varietal preferences of men and women. The researchers found that women mentioned weeding more often as a constraint, as it’s a task mainly done by women, whereas men referred to the lack of machinery for production. While both men and women seek out new varieties, it was found that men have more access to these varieties.

The researchers found that women often mentioned weeding as a constraint. It’s a laborious task mainly done using machetes. Credit: H.Holmes/RTB

On the other hand, the overall frequency of which most traits were mentioned is similar for men and women, who want cassava varieties with high yield, big roots and that mature early. “There’s a lot of cohesion between what men and women are telling us are the most important traits,” Tufan noted.

Men and women may prefer the same varieties, but for different reasons. For example, one variety, which farmers call ‘IITA’, is ranked highly by both genders. Men like it for its high yield and because it stores well in the ground, while women like its “good product quality” which means its pleasant taste and high dry matter content. A high dry matter content leads to good ‘swelling’ during processing, which is an important characteristic for women.

Understanding these differences helps breeders to select not just for high yield, but for other traits that are important for growers, processors and consumers. However, farmers’ concepts are often too complex to be captured in a simple trait list. For example, Nigerian farmers like gari that swells nicely. But there are three types of swelling –  when one adds hot water to make a paste called eba, when one eats the eba and it swells in the stomach and the swelling of the cassava mash when toasted into gari.

There is also a lot of variability in how gari is processed, which also influences how much it swells. Breeders still don’t know enough about the underlying genetic determinants to breed for good swelling cassava. Currently IITA and NRCRI are conducting participatory trials with farmers and processors in Imo and Osun States, Nigeria to disentangle these different effects.

So, identifying farmer ‘preferences’ is complex. Cassava farmers have a tacit feel for the traits they prefer but unpacking those into the underlying genetic determinants is challenging. Nor is there a simple binary list of traits preferred by women and by men.  But thanks to this effort, cassava breeders can now improve combined traits for product qualities, high yield and harvesting time.

Photo: Toasting cassava flour is the final step in creating gari, and is a task mainly done by women. Credit: H.Holmes/RTB