The role of CGIAR Germplasm Health Units in averting endemic crop diseases: the example of rice blast in Bangladesh

 Yuji Enriquez, Melinda Smale, Nelissa Jamora, Mohammod Hossain, and Lava Kumar   |  

Germplasm Health Units (GHUs) are institutional phytosanitary units of the CGIAR designed to facilitate bioresource transfer for their breeding programs and their genebanks. One CGIAR’s unknown success stories is the contribution of GHUs to reducing the risk of transboundary spread of pest and disease and the transfer delays that could have impaired time-sensitive progress in plant breeding.

The historic success of global agriculture research for crop improvement is built on the strong scientific partnership between the CGIAR centers and the national agricultural research systems (NARS). Since 2004, this has been further enabled by the International Treaty for Plant Genetic Resources for Food and Agriculture (or the Plant Treaty) of the Food and Agriculture Organization (FAO) and its Multilateral System for access and benefit sharing (MLS), which allows for unrestricted flow of plant genetic resources. The MLS is a breakthrough achievement of the Plant Treaty, to which all Contracting Parties adhere. The CGIAR is officially recognized as a supporting component to the Treaty (cfr. Art. 15 of the Treaty).

Since 2004, the contracting countries of the Plant Treaty have agreed to participate in the MLS in creating an international collection of genetic resources for 64 crops and forages, stored in a decentralized way in all participating genebanks around the world, listed in the Plant Treaty. National food systems have benefited from this partnership, especially in countries where diets and agricultural production systems largely rely on genetic diversity traceable to foreign origins.

However, seed-borne pathogens are often barriers to seed movement. Seed destination countries need assurance that the plant germplasm that enter their borders are free from any pathogen or pest of quarantine importance. The unintended introduction of diseases and pests is often irreversible and could spell significant crop losses.

The increased risk of transboundary transfer of diseases and pests would likely discourage access to and sharing of benefits from global use of germplasm and, worse, might lead to the tightening of national quarantine and administrative regulations. All these factors could slow down the international exchange of plant genetic resources.

In this regard, seed health testing and phytosanitary clearances are mandatory for collection holders or any other person who is involved in seed/germplasm exchange. Processes are regulated under the International Plant Protection Convention and respective policies of the national plant protection organizations (NPPOs) of all involved countries (i.e., the country hosting the collection/donor germplasm and the country requesting to import).

The CGIAR has an important role in the Plant Treaty. CGIAR centers agreed under the convention that the ex-situ collections under the CGIAR genebanks are made available and accessible through the MLS. Since the 1970s, CGIAR centers have established phytosanitary protection measures and protocols to ensure a pest-free international exchange of germplasm. The Germplasm Health Units (GHUs) were formalized in the 1990s to serve as a single gateway for international germplasm exchange through the recommendations of the Sixth International Plant Protection Congress in 1993 in Montreal. Some CGIAR centers, like the International Rice Research Institute (IRRI), name their GHUs as Seed Health Units (SHUs) because they deal mostly with seed crops.

The GHUs are institutional phytosanitary units of the CGIAR designed to facilitate bioresource transfer for their breeding programs and their genebanks. They work in close partnership with NPPOs to help perform their national mandates through awareness raising, capacity development, and partnership arrangements for phytosanitary regulation. At IRRI, for example, the functions and services for incoming and outgoing rice seeds for post-entry clearance and phytosanitary certification include the following: dry seed inspection; routine seed health testing, which screens for Tilletia arclayana and nematodes; blotter testing; bacterial testing; field or greenhouse inspection for newly introduced germplasms, wild rice varieties; seed treatment; and packaging.

In addition, GHUs maintain networks and relationships with country users and regulatory organizations; provide phytosanitary and regulatory information; disease surveillance; and generate and build the capacity of NARS partners on seed health, seed movement, and transboundary pest and disease. By providing crucial safeguards for the safe and efficient transfer of germplasm to crop improvement and genetic resource programs around the world, GHUs are instrumental for the effective development of international public goods.

The CGIAR GHUs are also making efforts to institutionalize a GreenPass System: a certification scheme for germplasm exchange. Apart from its processes, the GHUs also put in place networks and institutional arrangements that create value that supports both CGIAR and NARS partners.

Despite the almost two decades of CGIAR GHU existence, the causal pathway linking them to farmer welfare and the magnitude of economic benefits are largely unknown. This is perhaps because GHUs are perceived as service support units within the MLS that are related indirectly to the impacts of agricultural research on farms. But recent developments in modern breeding approaches have underscored the importance of timing in raising the rate of genetic gain (through rapid-cycle breeding) and in the dynamics of attaining durable protection from evolutionary capabilities of pathogens.

In this context, one of the CGIAR’s unknown success stories is the contribution of GHUs to reducing the risk of transboundary spread of pest and disease and the transfer delays that could have impaired time-sensitive progress in plant breeding. To date, there is no existing evidence that documents and quantifies the economic benefits and saved opportunity costs derived from the facilitation by CGIAR GHUs of safe and efficient international transfers of germplasm.

We address this gap by documenting the specific case of improving the durability of cultivated rice varieties to blast in Bangladesh. This enables us to demonstrate the pathway linking GHUs to impacts on farms. We apply impact pathways analysis and an augmented ex ante surplus model that simulates the impact on farm yields of blast R variety deployment over a 20-year period. Data sources included interviews with key experts, a national panel dataset collected from farm households, and field surveys of blast incidence and severity. Next, we present literature about rice blast and the breeding approaches that address this disease.

Rice is a significant income source for farmers in Bangladesh Pest and diseases, particularly blast, are key threats to farmers’ productivity and income. While fungicide can be an effective treatment, it adds substantial cost to farmers. But when they are needed the most during the cultivation season, most farmers find it difficult to access pesticides.

Rice blast is a serious fungal disease caused by Pyricularia oryzae Cavara (sexual morph Magnaporthe oryzae). Blast disease can infect the aboveground tissue of rice plants and all their organs at any developmental stage, which could cause total crop failure. Blast outbreaks are recurrent and known for their destructiveness across ecosystems and seasons.

With a long history of rice cultivation and dependence on rice for staple food security, Bangladesh confronts a severe threat from rice blast disease, with the potential to upturn its historical productivity gains. Estimates from various countries show that rice blast can result to 10–30% yield loss annually. Without preventive measures, in conditions most favorable to blast disease, it can also result in 100% losses in just a matter of 15–20 days of infection.

In Bangladesh, the computed yield losses from rice blast in ten representative agro-ecological zones (AEZ) could cause as high as 34.7% and 16.4% losses, a median of 16.85% and 11.35%, and lowest at 11.9% and 6.4% in an AEZ in irrigated area (Boro) and rainfed area (Aman), respectively.

The most popular rice varieties, including aromatic varieties, are susceptible to blast in wet (Aman) and dry (Boro) seasons and in rainfed and irrigated areas (Hossain et al. 2017). These include popular varieties like the Bangladesh Rice Research Institute (BRRI) dhan 29 and BRRI dhan 28.

Bangladesh Bureau of Statistics estimates in 2015–2016 that local rice varieties account for 1,440,635 ha with yield between 1.19 and 1.67 mt yield per ha and 47,300 ha with 1.89 mt yield per ha, in Aman and Boro respectively. The Bureau estimates that high-yielding varieties cover 4,149,705 ha with yield at 2.71 mt per ha and 4,043,531 ha with yield at 3.86 mt per ha, in Aman and Boro respectively. In the 2016 data of the Rice Monitoring Survey (RMS), the number of types of local varieties cultivated is estimated at 67 in Aman and 18 in Boro, while modern or high yielding varieties number 31 in Aman and 21 in Boro.

Since the 1980s, Bangladesh has struggled with several blast disease outbreaks. Further, climate change has brought early rainfall and temperature and humidity changes, making environmental conditions more favorable for blast pathogens to thrive and infect early maturing varieties.

Our study sheds light on the impact of the CGIAR GHUs by valuing the contributions of the IRRI GHU to the potential impact of breeding blast R rice varieties in Bangladesh. We did this by first looking through which pathways the IRRI GHU contributes to breeding impacts. We then conducted an economic surplus analysis for maintenance research to estimate the potential economic benefits of breeding resistance to blast.

We designed our surplus analysis parameter assumptions following the customized deployment strategy and linked the time-saving benefits of the IRRI GHU. We used Monte Carlo simulation to address sparse data challenges and to produce results augmented with risk analysis. We applied a partial equilibrium model to incorporate market-clearing price effects of local and international markets.

Our findings revealed that the IRRI GHU plays an indispensable role in ensuring robust international agricultural research, particularly time-sensitive breakthroughs to address highly adaptive virulent like blast, through safe and efficient access to diverse genetic resources and breeding technology.

This is achieved through combined diagnostics expertise and partnerships. Our findings indicated that the IRRI GHU has a modest likely benefits contribution of USD 5.9 million, a mean of USD 12.6 million, and a best-case scenario of USD 62 million, out of the total benefits of blast-resistance breeding of USD 295 million, USD 362 million and USD 1.461 billion, respectively. The IRRI GHU’s BCR results indicated that the return on investments in the GHU was high. It had a BCR of 112 for the most likely benefits, 305.8 for mean benefits, and 3666 for the best-case scenario estimate.

Our model simulation revealed that the extent of yield savings from resistance and discount rate (time value of money) most influence the resulting NPV of the IRRI GHU. The sensitivity of results to the rate of yield savings, which is contingent on the timing of deployment, yield performance, disease vulnerability, the effectiveness of varietal resistance, and lifespan of varietal resistance to blast, reinforced the importance of, and economic returns to, investing in robust international research.

Putting it another way, slowing down the international germplasm movement could take a toll on the future economic gains from agricultural research. Despite this, we note that the total benefits estimated by our study for the IRRI GHU are understated. Time-saving, while measuring an important contribution, captures partial or incremental benefits at best.

Read the study:
Enriquez Y. Smale M. Jamora N. et al. (2022) The role of CGIAR Germplasm Health Units in averting endemic crop diseases: the example of rice blast in Bangladesh. CABI Agric Biosci 3, 15.

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