By Takashi Yamano, Maria Luz Malabayabas & Manzoor H. Dar
Due to climate change, the frequency of floods and droughts is expected to increase. To reduce crop losses due to such abiotic stresses, stress-tolerant rice varieties have been developed and distributed to farmers in developing countries, including Eastern India. Benefits of stress-tolerant rice varieties, however, become observable to farmers only when they suffer from stresses. Below, Takashi Yamano, Maria Luz Malabayabas, and Manzoor H. Dar take an example of a submergence tolerant rice variety, called Swarna-Sub 1, and show how adoption of Swarna-Sub 1 increases significantly one year after farmers experienced floods in Eastern India.
Climate Change is expected to increase the number and severity of flood events in the future in India1. Approximately 80% of the rice-growing area in Eastern India is rainfed and exposed to abiotic stresses, such as floods. According to the International Disaster Database (EM-DAT), approximately 20 million people in India were annually affected by floods between 2001 and 2011. Because farmers are mostly poor in rainfed areas, crop losses caused by floods can have a devastating impact, potentially exacerbating poverty in the region. The International Rice Research Institute (IRRI) and its collaborators have developed rice varieties that are tolerant to various abiotic stresses. Recent advancements in conventional and molecular breeding techniques have facilitated the breeding of rice varieties with desirable traits in a relatively short period2. Swarna-Sub1 is a submergence-tolerant rice variety, which can survive up to 14 days of full submergence, and has been distributed in Eastern India since 2008 by Stress-tolerant Rice for Africa and South Asia (STRASA) project and its collaborators.
The benefits of stress-tolerant rice varieties, however, become visible only under stresses, and farmers may not observe benefits of stress-tolerant rice varieties under normal conditions. The limited visibility of the benefits may hinder diffusion of stress-tolerant rice varieties. The issue is essentially similar to the demand for insurance against extreme events. In the insurance literature, it is well documented that insurance purchases against extreme events remain low, leaving the majority of the people uninsured, until corresponding extreme events occur3. Thus, it is important for the public sector to intervene and increase awareness of possible extreme events induced by Climate Change and prepare them against such extreme events. In this article, we discuss preliminary results from our recent study about adoption of Swarna-Sub1.
Development of Submergence-tolerant Rice
Floods are highly unpredictable and may occur at any growth stage of rice. Yield loss due to flood could be anywhere between less than 10 percent and 100 percent, depending on factors such as water depth, duration of submergence, temperature, turbidity of water, rate of nitrogen fertilizer, light intensity, and age of the crop. Rice plants respond to flooding through two mechanisms: (a) elongation ability by which rice varieties avoid complete submergence through elongation of the plant above the rising flood water levels and (b) submergence tolerance by which certain rice varieties survive submergence of 10 days or more particularly in shallow water through metabolic adjustment4. As late as the 1980s, rice scientists identified some flood tolerant rice varieties that rely on the metabolic adjustment mechanism and tried to combine both desirable levels of flooding tolerance and high grain yield4. They could not, however, succeed through conventional breeding.
In the 1990s, rice scientists have found that the submergence tolerance in certain rice varieties is controlled by a single major quantitative trait locus (QLT), which is named SUB12. The SUB1 QTL provides tolerance to complete submergence up to 14 days. An Indian rice variety, called FR 13A, is found to possess SUB1 and has become a popular parental variety to provide SUB1 to rice breeders to combine it with popular rice varieties in India. Swarna is one of such popular Indian rice varieties. It is a modern rice variety developed in India in the 1980s and has since become one of the most popular rice varieties in East India. Adding submergence tolerance to the already popular Swarna makes it easy for farmers to adopt the new variety because they can cultivate the new variety as they cultivate Swarna. Finally, in the early 2000s, rice scientists successfully introgressed SUB1 QTL into Swarna through marker-assisted backcrossing5.
Under normal conditions, studies find no significant differences in agronomic performance, grain yield, and grain quality between Swarna and Swarna-Sub1, indicating complete restoration of the Swarna background Swarna-Sub16. Swarna-Sub1, however, shows a two-fold or higher yield advantage over Swarna after submergence for 10 days or more during the vegetative stage. Although SUB1 has been successfully introgressed into other mega rice varieties recent years, Swarna-Sub1 remains the most successful Sub 1 variety.
Picture 1 is taken on September 29, 2011, in Puri district of Odisha State, India, some weeks after submergence in the area. It shows a plot of Swarna-Sub1 in the back of the picture. Swarna-Sub1 crop is growing strong after the water has subsided, although the surrounding plots of Pooja, which is a popular rice variety in Odisha, have been completely destroyed by the submergence.
In 2008, STRASA project has started distributing Swarna-Sub1 seeds to farmers in India. The STRASA project coordinates the seed multiplication with local counterparts, such as universities and national agricultural research centers, and distributes the Swarna-Sub1 seeds through NGOs and governmental agencies. In 2008, the project distributed the seeds to only 117 farmers, but the distribution has been expanded exponentially to 3 million farmers in 2012. The expansion occurred when the National Food Security Mission (NSFM) of the Indian government started distribution of Swarna-Sub1 seeds in 2010.
Data
The data used in this paper come from two-visit surveys conducted in April-June and October-December in 2012. The surveys were conducted in six districts in Uttar Pradesh (UP) and two districts in Odisha. The eight districts were chosen from a list of districts where four local NGOs have distributed Swarna-Sub 1 seeds in mini-kits, which consist of only seeds. The distribution started from 2008 but was scaled-up in 2011. We received lists of villages and farmers who have received the mini-kits. The lists were provided by four NGOs who have been involved in Swarna-Sub1 seed distributions in the study area. From the village list, we randomly selected 52 villages in Uttar Pradesh and Odisha. From the recipient lists, we randomly selected 629 farmers.
Yield of Swarna-Sub 1 under Submergence
As we mentioned, the benefits of Swarna-Sub1 can be observed when the length of the submergence is shorter than 15 days. In Figure 1, we present the average yields of Swarna-Sub1 and Swarna in 2011. The average yield of Swarna is about 4.5 tons per ha when there is no submergence. However, the average yield declines to 3.0 tons per ha when farmers suffer from short-duration submergence (1 to 7 days). The yield declines to 1.4 tons per ha under medium-duration submergence, and the crop is completely destroyed under long-duration submergence.
The yield of Swarna-Sub1 also declines as the length of submergence increases but less drastically. The average yield of Swarna-Sub1 is about 4 tons per ha without submergence. The difference between that of Swarna is less than 0.5 tons per ha. When farmers suffer from short- and medium-duration submergence, the average yield of Swarna-Sub1 decreases to 3.7 and 2.9 tons per ha, respectively, but it is higher than that of Swarna under the same conditions. The difference in average yields between Swarna and Swarna-Sub1 is about 0.6 tons per ha under short-duration submergence and about 1.2 tons per ha under long-duration submergence. The both differences are statistically significant which suggests that Swarna-Sub1 can survive up to 15 days of submergence. Under the long-duration submergence, even the yield of Swarna-Sub1 declines to less than 1 tons per ha, although the yield difference between Swarna and Swarna-Sub1 1 is not statistically different because the number of observations is small.
Thus, Figure 1 clearly shows the benefits of Swarna-Sub1 under short- and medium-duration submergence. However, the yield of this is not different from that of Swarna, or it could be lower than that of Swarna without submergence. Only when farmers experience short- and medium duration submergence can they observe the benefits of Swarna-Sub1. Without seeing the realised benefits of Swarna-Sub1, farmers may remain indifferent about the new variety and remain unprepared against future floods.
Adoption and Perception of Swarna-Sub 1 after Submergence
To find farmers’ reactions to their experience of submergence in 2011, we have created three categories of submergence based on the length of the submergence (Table 1) we find that the average adoption rate of Swarna-Sub1 remains at 27.5 percent in both years. After farmers experienced short-duration submergence in 2011, however, the adoption rate of Swarna-Sub1 increased from 3.2 percent in 2011 to 16.1 percent in 2012. The increase is about 13 percentage points. When farmers suffered from medium-duration submergence, the adoption rate increased from 19.3 percent to 21.6 percent.
When the duration was longer than 15 days, the adoption rate decreased from 36.4 percent in 2011 to 27.3 percent in 2012. This is partly because some farmers who adopted Swarna-Sub1 misunderstood that this can even survive under stagnant water and be cultivated in areas that are prone to stagnant submergence. This misunderstanding was observed more often in Uttar Pradesh. After suffering from long-duration submergence in 2011, farmers realised that Swarna-Sub1 is not suitable for areas prone to stagnant water and have switched to different rice varieties.
To measure the perception of Swarna-Sub1 among farmers, we have asked farmers about this by asking them to evaluate 5 statements on a 5 point Likert scale. Scale 1 indicates a strong disagreement; whereas Scale 5 indicates a strong agreement. The five statements are the following: (1) I think Swarna sub1 is a very good variety, (2) Other farmers think Swarna-Sub1 as a good variety, (3) It is easy to adopt Swarna sub1, (4) Swarna-Sub1 tastes better than other varieties, and (5) Swarna-Sub1 is more submergence tolerant. We do not present the results on these five statements in this article, but we have created the perception index of Swarna-Sub1 by using the answers to the five statements. The index was created based on Factor Analysis.
In Table 1, we find that the perception index is high among households who experienced medium-duration submergence in 2011. The average score of the index is 0.17 among farmers who experienced medium-duration submergence in 2011, while the average is -0.24 among farmers who did not experience submergence, -0.05 among farmers who experienced short-duration submergence, and 0.02 among farmers who experienced long-duration submergence. Thus, the results in the table suggest that the adoption rate of Swarna-Sub1 increased among farmers who experienced short- and medium-duration submergence in 2011 and that farmers who experienced medium-duration submergence have a high perception of Swarna-Sub1.
Conclusion
In this article, we have shown the effect of visible benefits of Swarna-Sub1 on its adoption and perception among farmers. To measure the effect of visible benefits of a stress-tolerant variety, we have examined the adoption of Swarna-Sub1, which is a submergence tolerant rice variety which has been developed recently and distributed in Eastern India. By using data from 629 rice farmers in 2011 and 2012, we find that the adoption rate increased in 2012 among farmers who experienced submergence in 2011. We also find that farmers’ perception of Swarna-Sub1 is also high among them. Thus, just as the demand for flood insurance increases after severe floods occur, our sample farmers have adopted Swarna-Sub1 and have a good perception of it after they experienced submergence. To promote Swarna-Sub1 and other stress-tolerant crops among farmers, we should use such knowledge to promote such crops so that farmers will be insured against Climate Change induced extreme events in the future.
About the Authors
Takashi Yamano is Senior Scientist (Agricultural Economics) at International Rice Research Institute. He received the Outstanding Journal Article Award from American Journal of Agricultural Economics in 2006. He has co-edited Emerging Development of Agriculture in East Africa (Springer, 2012). He obtained a Ph.D. degree from Michigan State University in 2000. (Corresponding author)
Manzoor Hussain Dar is Senior Associate Scientist at International Rice Research Institute. He has been coordinating for seed up-scaling and dissemination for Stress-tolerant Rice for Africa and South Asia (STRASA) project since 2009.
Maria Luz conducts research in the socio-economic component of Stress-tolerant Rice for South Asia and Africa (STRASA) project at IRRI. She joined IRRI in 2008 after completing her MS in Agricultural Economics from University of the Philippines Los Baños which specializes in agricultural marketing and policy development.
References
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