Category Archives: News

Disease-resistant potato and banana give hope to farmers

Late blight remains one of the most devastating diseases for potato worldwide, costing farmers an estimated USD3 – 10 billion per year globally. Traditional breeding for resistant varieties takes years, and resistance can break down as the pathogen mutates when it encounters resistance genes, leaving farmers no options than using fungicides up to 15 times per season. Similarly, banana Xanthomonas wilt (BXW) is a growing threat to the livelihoods of small-scale farmers. Since its appearance in Uganda in the early 2000s, BXW has spread rapidly in the region, causing food insecurity and income loss. No resistant cultivars have been identified, and it can only be controlled through on-farm management practices.

In the face of these serious and persistent challenges to food security and livelihoods, RTB centers and national research partners have developed a biotech late blight-resistant potato with multi-gene resistance, and a BXW-resistant cooking banana variety for East Africa. Confined field trials have shown the crops to be very disease resistant, and otherwise identical to the original varieties.

In 2017, a RTB cross-crop initiative began to ensure the responsible management and regulation of biotech crops. Stewardship in plant biotechnology is the responsible management of a product from its inception through its ultimate use (learn more: In addition, biotech crops need to be assessed for their safety to humans and animal health prior to release to the public for commercialization. Environmental risk assessments are also an essential part of regulatory decision-making for biotech crops. Consequently, stewardship plans along with risk assessments and experimental evidence are required to gain regulatory approval and for the responsible cultivation of these crops.

Continue reading the story in the RTB 2017 Annual Report: From science to scaling

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.

Similarly, the RTBfoods project led by Dominique Dufour, Food Scientist at CIRAD is also working to understand gender differences in trait preferences for important food and income-generating root and tuber products, with the aim to develop new varieties that meet the needs of men and women producers, processors and consumers. “Creating an evidence base for crop and product preferences by gender and other factors of social difference is a new and innovative approach that we are excited about. Importantly, this will further the contributions of breeders to improving food security and income generation in sub-Saharan Africa,” explains Lora Forsythe of the Natural Resources Institute, who leads Work Package 1 on preferences for the RTBfoods project.

Continue reading the story in the RTB 2017 Annual Report: From science to scaling

Pest distribution and risk atlas for Africa includes potato and sweetpotato pests

Insect pests cause major yield losses in agricultural crops. Climate change is expected to exacerbate this impact, with warming temperatures affecting insect populations, range expansion and outbreaks. To inform the development of integrated pest management strategies, the International Potato Center (CIP) launched an online Pest Distribution and Risk Atlas for Africa in early 2017.

This open-access, mobile-accessible resource combines up-to-date information on major insect threats to potato, sweetpotato, vegetable and maize production with current risk maps for each pest and predictions for future climate scenarios. Researchers, agricultural ministry officials and extensionists can use that information to plan efforts that help farmers better manage crop pests now and prepare for future threats. The maps were generated using insect life cycle modelling software (

“Any increase in temperature caused by climate change will have drastic effects on pest invasions and outbreaks that will affect pest management, crop production and food security,” said Jürgen Kroschel, CIP Agroecology and Integrated Pest Management science leader, who started the Pest Risk Atlas project.

Continue reading the story in the RTB 2017 Annual Report: From science to scaling

Competition calls for innovative packaging of cassava stems to increase sales

A new competition is calling for innovative packaging designs to sell bundles of high quality cassava stems in Nigeria.

The competition has been launched by the ‘Building an Economically Sustainable, Integrated Seed System for Cassava in Nigeria’ (BASICS) project, which aims to develop a sustainable cassava seed value chain in Nigeria, based on the commercial production and dissemination of improved cassava planting material.


A farmer carries a bunch of cassava stems in Nigeria. Photo IITA

This seed value chain will serve as a vehicle to deliver better quality and more productive cassava varieties in order to improve productivity and food security, increase incomes of cassava growers, processors and village seed entrepreneurs, and enhance gender equity in Nigeria.

Currently, most cassava farmers use the stems from their own farm for planting or buy stems of dubious quality from the local market. To sustainably and significantly change farmers’ behavior to buy improved and quality certified stems, at least two things need to happen:

  1. The improved variety stems need to result in the farmers getting higher cassava production and ultimately translate that into higher net incomes, consistently, meaning that the variety needs to meet the contextual market demand. (Substance)
  2. The improved stems need to be presented well, packaged well and they need to result in a visibly improved crop stand in the farmers’ fields. (Style)

While the ‘substance’ is of greater importance in long term success, the ‘style’ is important to get the attention of the market to influence the initial buying behavior and hence is a vital part of marketing of any new product or service.

This competition invites innovative ideas for the ‘style’ or presentation of the cassava stems. Participants should submit their proposal in maximum of three pages on how to make a bundle of improved/certified cassava stems more marketable to farmers on a large scale.

Entries must include the following:

  1. Your contact details and a brief profile
  2. Cassava stem bundle treatment, packaging, labeling and handling proposal
  3. Overall additional cost per bundle of 50 one-meter stem cuttings (you can make explicit assumptions to get reasonable economies of scale)
  4. What attributes brought about through your proposal do think will entice the farmers to pay the higher price to buy your bundle of stems and come back as a repeat buyer or become an advocate for it?

Any individual or a group of individuals or an institute who has the ability to demonstrate the proposal in Nigeria is eligible to participate.


  1. $1,000 cash prize for the best proposal
  2. A Certificate Of Appreciation for the TOP THREE proposals signed by the Program Director, CGIAR Research Program on Roots, Tubers and Bananas (RTB) and Deputy Director General for Research, IITA
  3. $5,000 award for implementing a pilot project of the proposal as a part of the BASICS project. (only if the committee feels the technology/proposal is mature enough to be piloted)

Judging criteria
Entries will be judged based on attractiveness of the proposed presentation of the stems in the eyes of various stakeholders, practicality of the proposal, on ease of availability of additional inputs being suggested, ease of handling of the bundle, tamper proof certification tagging of the bundle, overall cost and value for money considerations.

Important note
Please note that this is not a research proposal. It is expected that you would have experimented and come up with something that is now ready to be tested on a commercial pilot level. Or it could be a proven native knowledge that has been lost to the world and is waiting to be rediscovered. There could be ideas that improve the packaging of the stems and improve ease of handling, there could be methods for improving the look and feel through some low cost dyeing of the stems or some nutrient/fungicide dips to improve the crop establishment in the field. Your proposal could address just one or multiple issues at the same time and the most commercially viable proposal will be picked.

The entries should be submitted in the format mentioned above and should not be more than three pages long. The committee may seek more information at an appropriate time, if required.

Entries should be emailed to by July 25, 2016.

Download the full competition details

Understanding potato seed degeneration to increase yields in Ecuador

The resilience of potato production systems in Andean countries heavily depends on seed quality. Under local conditions in Ecuador, the variation in seed quality has been estimated to account for 30% of variation in attainable potato yield. This is critical for the country’s estimated 85,000 potato farmers, of which around 75% are small-scale producers. Farmers’ seed quality is usually poor because of degeneration, which is the increase in incidence of pests or pathogens in the seed tuber leading to yield loss and a decline in seed quality over successive cycles of vegetative propagation.

One of the pathogens causing seed degeneration is Rhizoctonia solani which is disseminated by the seed tuber (black scurf) or the soil. Yield losses caused by R. solani in potato in Bolivia, Ecuador and Peru have been reported to be up to 20%, indicating the importance of the pathogen for the Andean region. Despite this, the influence that the sources of infection and the density of the pathogen have on potato seed degeneration and on fungal soil colonization has been poorly quantified and understood.

To understand the role of inoculum sources and inoculum densities on the potato seed degeneration caused by R. solani, researchers from the International Potato Center, the Centre for Crop System Analysis and the Laboratory of Phytopathology of Wageningen University set up a glasshouse experiment at Wageningen University with different levels of R. solani on the seed tuber and in the soil. To explore how these factors influence the extent to which the pathogen infects the surrounding soil, DNA was extracted from soil samples taken from the pots at 30, and 60 days after planting and one day before harvesting. Then, the absolute amount of DNA of R. solani was quantified using real-time PCR.

Assessing sources of infection and the density of the pathogen on potato plants

“Our results found that the disease delays the emergence of the potato plants and consequently causes problems in the management of the crop. This means that we need to be careful with the tubers that we are planting because these may affect the development of our crop,” explains MSc student Israel Navarrete from Wageningen University, whose research scholarship for the project was funded by the McKnight foundation.

fgfg“Additionally, our results show that the pathogen can disseminate aggressively on the tubers and in the soil and that IPMs need to take into account not only the health of the seed, but also the health of the soils. The results also found that we can monitor the disease either in the soil or in the tuber, making it possible to integrate this in Integrated Pest Management strategies,” he says.

Effects of R.solani on emergence and amount of R.solani DNA on tubers

The researchers concluded that both inoculum sources are relevant to reduced seed quality regardless of the inoculum density, and that soil colonization by R. solani is similar after 30 days after planting.


“These findings will eventually be translated into better pest management strategies in order to improve the quality of the seed produced by smallholder farmers, and improve the health of the Ecuadorian soils for the benefit of the same farmers. Monitoring strategies can be designed to understand the variation of the pathogen on Ecuadorian farms, and reduce the impact of the pathogen on farmer fields,” explains Israel.

Better management of critical pests and diseases is an essential step towards helping boost Ecuador’s potato production (9 ton per hectare), which continues to be much lower compared to its neighbours, Colombia (19 ton per hectare) and Peru (14 ton per hectare). This will bring much needed income and food security for the country’s small-scale producers.

This research was conducted as part of the ‘Seed degeneration of roots, tubers and bananas’ project funded by the CGIAR Research Program on Roots, Tubers and Bananas.

CIP Leads Initiative to Understand how Climate Change Affects Pests


cc1Weather station with farmers and project team members from RAB and CIP

The Paris Agreement of December 2015 heralds a greater global effort to reduce greenhouse gas emissions and mitigate the effects of climate change, yet farmers around the world are already dealing with the consequences of a warming atmosphere. While more frequent droughts and floods are causing widespread crop damage, the greatest threat to farmers from global warming may be the growing abundance and expanding distribution of crop pests and diseases.

“A crop pest that currently produces three or four generations per year may produce as many as six or seven generations per year once average temperatures rise by 2ºC—3ºC,” warned Jürgen Kroschel, Team Leader for Agroecology and Integrated Pest Management at the International Potato Center (CIP).


Pests and diseases already pose major threats to the food security and livelihoods of smallholders in developing countries, yet there is a shortage of information about how much and where climate change will transform those threats. To help fill that knowledge gap, Kroschel is coordinating a CIP-led, multi-crop collaboration with several other international research centers and national programs to predict how global warming will affect some of the most destructive crop pests and diseases in East Africa. The initiative’s ultimate goal is to help local government agencies and the farmers they serve to better assess, prepare for, and confront the risk of crop pests and diseases as the climate changes.

Altitude gradient which covers all RTB crops

Funded by the CGIAR Research Program on Roots, Tubers and Bananas (RTB), the initiative focuses on the critical pests and diseases affecting potato, sweetpotato, banana and cassava in Africa’s Great Lakes Region. It combines the expertise of researchers from CIP, Bioversity International, the International Center for Tropical Agriculture (CIAT), the International Institute of Tropical Agriculture (IITA), the UK’s Food and Environment Research Agency (Fera) and Commonwealth Agriculture Bureau (CABI), US universities and national programs in the region. Some of the tools those researchers are using were developed during a prior CIP project to model climate change’s impact on insect pests in Africa, which was funded by the German Federal Ministry of Economic Cooperation and Development (BMZ).

Researchers have been working in both the laboratory and in the field, namely the Ruhengeri area of Rwanda and Burundi’s Rusizi Valley, both of which hold a wide diversity of farming systems along an altitudinal gradient, and where banana, cassava, potato and sweetpotato are widely grown. CIP, Bioversity, IITA and national partners began there by coordinating a socioeconomic baseline survey of more than 400 farm households in the two countries, and installing networks of weather stations at different altitudes to provide a regional climatic database. The researchers are studying farms at different altitudes to better understand the role that altitude plays in pest distribution and intensity as the temperature rises.


“We are not only studying the impacts of climate change on pests and diseases, but on the livelihoods of farmers in these areas,” said Kroschel.

At the same time, scientists at CIP, Bioversity, CIAT and IITA have conducted laboratory research to better understand how rising temperatures affect the development of specific pests – data that are being used to predict how climate change will increase the risk they pose. To do this, researchers use Insect Life Cycle Modeling (ILCYM) software, which was developed by CIP’s agroecology modeling team under the previous project.

“You need individual assessments for each species to predict changes under rising temperatures. You can’t generalize,” explained Kroschel.

Thanks to the RTB initiative, software that CIP developed using potato pests is now being applied to insects that attack an array of other crops. Kroschel added that researchers are also trying to determine how climate change will affect the transmission of viruses by insects that serve as vectors for crop diseases.


Typical farm households and surrounding crops

An important project goal is to facilitate and improve risk assessments for the most critical insect pests and pathogens, which will help the region’s governments, non-governmental organizations and the private sector to confront those threats. The participating research centers are working with national programs in several East African countries to strengthen pest surveillance and the capacity to elaborate and act upon pest risk analysis (PRA) documents, which can be an important tool in national or regional efforts to help farmers prepare for pest risks.

CIP prepared PRA documents for the Guatemalan potato tuber moth (Tecia solanivora) and tomato/potato leaf miner (Tuta absoluta) that were used and further adapted during a training course for officials from Burundi, DR Congo, Uganda and Rwanda in October 2015. The elaboration of PRAs for several cassava and banana diseases is underway, led by IITA and Fera.

Kroschel noted that this project complements efforts by the Food and Agriculture Organization of the United Nations (FAO) to promote the production and use of PRA document’s by African ministries of agriculture.

While the threat that pests and diseases pose to crops is bound to grow under climate change, the good news is that there is a concerted effort underway to help farmers in East Africa to prepare for it.

By: David Dudenhoefer