Farmer-preferred, CBSD-resistant cassava varieties released by Central Africa breeding program

1 July 2022

The USAID-funded Action to Control Cassava Brown Streak Disease (CBSD) in the Democratic Republic of Congo (DRC) hosted the ceremony to nominate newly released cassava varieties. They were selected using end users’ preferences, particularly resistance to CBSD, in a participatory variety selection (PVS) approach, completed by a sensory test. The naming ceremony took place in the Ruzizi Plain, South Kivu Province, DRC.

The PVS comprised a collection of some of the best-improved varieties released earlier in DRC, and promising clones in advanced breeding trials were screened over three years in a CBSD’s hotspot site of the Ruzizi Plain. From a total of 30 genotypes in the first year, eight clones were subjected to a final evaluation along with check varieties comprising two improved (a resistant variety ‘NAROCASS 1’ and a susceptible variety ‘OBAMA’) and a popular local variety (Dorotea). Unfortunately, all the improved varieties succumbed to CBSD for leaf and root necrosis.

From the field evaluation, five clones, free from CBSD roots symptoms at harvesting, were selected by farmers. The data confirmed that the five clones outperformed the checks with the agronomic data collected. Among these five clones, two were chosen for leaf quality as vegetables because of their light red petiole, indicating that they would require less oil to cook.

Sensory test

In addition, the roots of each evaluated variety were processed either as chikwangue or flour to prepare fufu—the main market product of cassava in DRC. Consumers assessed prepared foods during the sensory test, from where four clones were rated as the best among the five previously selected in the fields. These four clones showed good quality of paste and chikwangue and were proposed for release.

The naming ceremony was held at Kamanyola, near Katogota in the Ruzizi Plain. Fifty-two participants attended (27 females and 25 males), including 36 community members, particularly farmers, and 16 technicians and researchers from seed multipliers and other private sector stakeholders, the Director of Mulungu-INERA research station and team, SENASEM, IITA, and SNV (extension agents), local authorities and the Inspector of Agriculture of Kivu.

IITA Cassava Breeder Sikirou Mouritala said, “The serial MVZ of these released varieties are triple resistant to major diseases like CMD, cassava root necrosis disease (CRND), and CBSD in DRC. It is the beginning of a new era in the DRC breeding program. The next step is to have our varieties in large farmer fields all over DRC to establish a good seed system sector and show more of IITA’s impact on food security in DRC.” He continued, “Work is in progress with the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures with the NextGen project to develop immune varieties for CBSD disease and resistant cultivars suitable for cultivation in DRC. While intensive efforts are focused on preventing the westward migration of CBSD with the IITA Tanzania team.”

Contributed by Michèle Kimpwene