Assessing the transition and stability in sweet potato production: An Indian perspective

Introduction

Sweet potatoes are a critical, multifunctional crop across the world, and especially in the developing world, because they are adaptable, have low input needs, and drought tolerance, which makes them a key crop in ensuring food security. They are economically important as a food staple, animal feed, and raw material for items such as flour, starch, and bioethanol, and the source of rural livelihoods through income creation and jobs in farming and commerce. Their compact growth period allows for several harvests a year, suitable for resource-poor areas. Growing global demand, particularly in health-oriented markets, has boosted export of sweet potato products, earning foreign exchange. Their use also in bio-based industries, like biodegradable packaging and biofuels, highlights their contribution to sustainable agriculture and poverty reduction.

World Scenario

Sweet potatoes are a globally important crop, grown in more than 100 countries, with an average annual yield of about 92 million metric tons. The biggest producer is China, which accounts for more than 55% of world production, mainly for animal feed and industrial purposes. Sub-Saharan Africa, especially Nigeria, Uganda, and Tanzania, depends substantially on sweet potatoes as a source of food security, particularly the orange-fleshed variety that is high in vitamin A. Production covers approximately 8 million hectares, with Asia and Africa responsible for almost 90% of the land. Production in developed nations such as the U.S. has increased by catering to increasing demand for healthy foods. Sweet potatoes are an important crop in food, animal feed, and industrial sectors with international exports worth more than $750 million. They are also valuable for sustainable development, thriving on poor soils with low inputs, and enhancing food security, especially through the campaign against vitamin A deficiency with orange-fleshed ones.

Indian Scenario

Sweet potato is a significant crop in India, produced in states such as Odisha, Uttar Pradesh, West Bengal, and Bihar, yielding around 1.1 million metric tons each year in 2021-22 from an area of approximately 120,000 hectares. Grown mostly by small, marginal farmers through traditional practices, it grows in rainfed, low soils and is prized for its climatic hardness. Odisha dominates production, accounting for over 25% of national production, and the crop is important in food security and supplementary income. High in starch, fiber, and vitamins, sweet potato is marketed for its nutritional value and has attracted interest for value-added items such as flour, starch, and crisps. High-yielding, disease-free varieties have been developed by the Indian government and research stations, including the CTCRI, to increase productivity. Though being mainly domestically consumed, India is increasingly exporting to the Middle East and Southeast Asia, adding to the increasing economic and nutritional worth of sweet potatoes in India. Markov Chain Structure Transitions between such states over successive years were utilized in creating a first-order Markov transition matrix. The transition probability is defined as the probability of transitioning from state in year to state in year. showed an increase in 2022-23 and 2023-24, while its productivity remained largely stable throughout the years. The uneven trend in sweet potato cultivation is attributed to varying agro-climatic conditions, regional dietary habits, and market demands. The compound annual growth rate (CAGR) for the area, production, and yield of sugarcane in India was calculated to assess growth trends over time in Table 2. The data shows that the annual growth rates for these parameters are uneven. The area under sugarcane cultivation increased significantly between 2014-15 and 2015-16, with the highest growth of 17.76% recorded in 2015-16. Conversely, the sharpest decline in area was observed in 2018-19. Periods of increased area consistently corresponded with higher production, with the highest growth in production also recorded in 2015-16. Yield showed notable improvement in 2023-24, driven by the adoption of highyielding varieties, enhanced farming techniques, and government support through agricultural schemes.

Results and Discussion

Additionally, increased awareness of sugarcane's economic and nutritional value motivated farmers to focus on quality production. Table 3 presents state-wise data on the area, production, and productivity of sweet potato in India for 2023-24. Odisha emerged as the leading sweet potato producer, followed by Uttar Pradesh and West Bengal. The study shows that production is directly proportional to the area under cultivation. The total production in India was 13.11 million tonnes, with Odisha alone contributing 335.46 million tonnes (25.59% of the total). Uttar Pradesh produced 263.78 million tonnes (20.12%), ranking second, while West Bengal contributed 175.66 million tonnes (13.40%), securing the third position. Madhya Pradesh followed with 114.77 million tonnes (8.79%). States like Karnataka, Jharkhand, Chhattisgarh, and Bihar also significantly contributed to production, with shares ranging between 3% and 9%. In contrast, Maharashtra, Meghalaya, Nagaland, and several other states reported minor production. Sweet potato productivity in India averaged 11.8 MT/hectare in 2023-24. Jammu and Kashmir recorded the highest productivity at 30.10 MT/hectare, attributed to favorable agro-climatic conditions, including a high-altitude environment that reduces pest and disease risks. Andhra Pradesh ranked second with 30.01 MT/hectare, and Bihar secured third place with 18.68 MT/hectare. Despite being the top producer, Odisha's productivity was close to the national average. On the other hand, Maharashtra and Meghalaya reported very low productivity due to challenges like erratic rainfall, traditional farming methods, poor soil quality, and limited technological advancements. Additionally, pest control and post-harvest management issues further hinder productivity in these states. 4 depicted the dynamics behind these annual changes, the research employed a first-order Markov chain model, classifying each year's change in area into one of three discrete states: Increase (I), Stable (S), and Decrease (D).

The core finding from the transition matrix is the high persistence of state transitions. For instance, if in a given year the area decreases, there is a 60% probability that the following year will also experience a decrease (D → D). Similarly, the Increase state shows a 50% chance of remaining in that state the following year (I → I), and the Stable state remains stable half of the time (S → S = 50%). This structure highlights that each trend tends to continue once established, especially for declines. The low transition probability from Decrease to Increase (only 10%) is particularly important. It means that once the cultivation area shrinks, recovery in the following year is unlikely unless deliberate efforts are made. This persistence reflects a kind of inertia in cultivation behavior, which may stem from limited responsiveness to short-term policy incentives, or long lags in cropping decisions due to agronomic, economic, or institutional factors. The steady-state probabilities (Table 5), derived from the transition matrix, provide insight into the long-term equilibrium behaviour of sweet potato area dynamics under the assumption that the transition structure remains constant. The steady-state results suggest that, in the long run, the area under sweet potato cultivation is most likely to be in the Increase state (45%), followed by Stable (35%), and least likely to be in Decrease (20%). This distribution provides a more optimistic outlook than the short-term transitions might suggest. Despite periodic contractions, the system gravitates toward expansion and stability in the long run. It implies that without external shocks, the sweet potato cultivation area has a natural tendency to stabilize or grow over time. This finding can be encouraging for policymakers and stakeholders, indicating that the crop's long-term prospects may remain positive if short-term dips can be mitigated effectively. www.extensionjournal.com Together, these charts help communicate the core statistical message to a non-technical audience: current states are likely to continue, but in the bigger picture, sweet potato cultivation is expected to recover and even grow, provided the conditions are supportive.

Conclusion

The findings from both the trend and Markov analyses have significant policy implications. The persistence of contraction states suggests that intervention during downturns is crucial. If a decline is not addressed promptly, it has a strong chance of persisting or only slowly reverting. Therefore, policymakers should target years of area decrease with proactive support measures-such as subsidies, seed distribution, price support mechanisms, and irrigation facilities-to prevent long-term damage to cultivation potential. Moreover, the steady-state forecast showing a 45% longterm probability of growth highlights a window of opportunity. Strategic investments during stable periods could tip the balance further in favour of the growth state. Supporting farmers with technology transfer, better storage facilities, value addition, and market linkages could help convert short-term stability into long-term expansion. Encouragingly, this analysis reveals that sweet potato cultivation is not on a path of irreversible decline-rather, it has latent potential that can be activated through informed, data-driven agricultural planning.

References

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