An analytical study on the growth, instability and decomposition of area, production and productivity of major oil crops in Theni District, Tamil Nadu

Introduction

Agriculture has long been the backbone of the Indian economy. Tamil Nadu is one of the leading agricultural states in India and ranks as the tenth largest state by area and the seventh most populous, accounting for about 6 per cent of the country's population. Theni district is one of the important agricultural districts of Tamil Nadu, where agriculture is the primary occupation. The district has favourable agro-climatic conditions for cultivating major oil crops such as groundnut, sesamum and coconut, which contribute significantly to the agricultural economy. Oilseeds are an important component of India's agricultural sector, contributing to food and nutritional security as well as farmers' livelihoods. They are a major source of edible oils, dietary fats and energy, while also serving as important cash crops that generate rural income and employment. India produced 12.18 million tonnes of edible oils during 2023-24, meeting only about 44 per cent of its domestic demand through domestic production. Although the country's dependence on edible oil imports has declined from 63.2 per cent in 2015-16 to 56.25 per cent in 2023-24, rising consumption continues to widen the gap between production and demand, highlighting the need to enhance domestic oilseed productivity [1]. Oil crop production in Theni plays a vital economic and agricultural role, utilizing roughly 10% of the district's cultivated land.

Review of Literature

Kalidas et al., (2020) [6] analyzed the growth, instability and decomposition of coconut production in India and Tamil Nadu using secondary data for the period 2001-2019. The study employed Compound Annual Growth Rate (CAGR), Coppock's Instability Index and decomposition analysis. The results indicated positive growth in coconut production in India (0.74%), while Tamil Nadu showed a declining trend (-2.48%). The study also found that the area effect contributed more to production changes than the yield effect at both the national and state levels. Joseph and Karunakaran (2022) [5] examined the growth and instability of major oilseed crops in India using data from 1989-90 to 2018-19. The study found that groundnut, rapeseed-mustard and soybean accounted for 86.42 per cent of the total oilseed area and 90.95 per cent of production. The compound growth rates of area, production and yield were positive throughout the study period. However, the instability in yield was highest for groundnut and soybean, indicating the need to improve productivity and stabilize production. Dash et al., (2023) [2] reported that the growth rate of groundnut area in Odisha declined significantly from 8.17% during the pre-liberalization period (1970-71 to 1995-96) to 0.13% in the post-liberalization period (1996-97 to 2019-20). In contrast, productivity growth improved from 1.26% to 2.94%, indicating enhanced yield performance after liberalization. However, production growth decreased from 7.34% to 3.04%, primarily due to the reduction in cultivated area. The study concluded that improvements in productivity were insufficient to offset the decline in area, resulting in slower growth in overall groundnut production. Compound growth rate is computed using the following formula.

Objectives of the Study

Compound Growth Rate (CGR) = (Antilog (log e b)-1) *100 Growth rates were estimated to assess the trend in area, production and productivity over time. In this study, the Compound Growth Rate (CGR) was used to measure the rate of increase or decrease in the major oil crops (Groundnut, Sesamum and Coconut) during the study period.

Instability index

The Cuddy-Della Valle Instability Index (CDVI) was used to measure the instability in area, production and yield of the major oil crops (Groundnut, Sesamum and Coconut) during the study period. The Cuddy Della Valle index (CDVI) was calculated as follows:

Results and Discussion 1. Groundnut

As presented in Table 1, the area under Groundnut cultivation recorded a negative compound growth rate (CGR) of -1.65 per cent, indicating a gradual decline in cultivated area during the study period. However, production and productivity registered positive growth rates of 1.88 per cent and 3.70 per cent, respectively, suggesting that improvements in yield compensated for the reduction in area. The CDVI values further indicate that production (25.31 per cent) was slightly more unstable than productivity (25.07 per cent), while area (16.42 per cent) remained comparatively more stable. As shown in Table 2, the productivity effect contributed 5,488.17 metric tonnes (343.99 per cent) to the net change in production, highlighting that yield improvement was the major source of production growth. In contrast, the area effect contributed -1,542.00 metric tonnes (-96.70 per cent), indicating that the reduction in cultivated area had a negative influence on production. Likewise, the interaction www.extensionjournal.com effect contributed -2,351.55 metric tonnes (-147.29 per cent), further offsetting production gains. Nevertheless, the positive productivity effect outweighed these adverse effects, resulting in a net increase of 1,594.62 metric tonnes in Groundnut production.

Sesamum

Table 1 indicates that Sesamum cultivation experienced positive growth in all three components during the study period. The compound growth rates for area, production and productivity were 3.07 per cent, 3.99 per cent and 0.90 per cent, respectively. The instability analysis shows that production (67.27 per cent) exhibited the highest variability, followed by area (37.26 per cent) and productivity (32.35 per cent), indicating considerable fluctuations in production over the years. According to Table 2, the productivity effect accounted for 142.02 metric tonnes (82.85 per cent) of the total increase in production, indicating that yield improvement was the principal factor responsible for output growth. The area effect contributed 16.17 metric tonnes (9.43 per cent), while the interaction effect contributed 13.23 metric tonnes (7.72 per cent). Overall, the combined effects resulted in a net increase of 171.42 metric tonnes, with productivity emerging as the dominant contributor.

Coconut

It is evident from Table 1 that the area under Coconut cultivation expanded during the study period with a compound growth rate of 2.47 per cent. Production also registered a positive growth rate of 0.60 per cent, whereas productivity recorded a negative growth rate of -1.82 per cent, indicating a declining trend in yield over time. The instability analysis revealed that area (4.53 per cent) remained highly stable compared with production (23.66 per cent) and productivity (23.69 per cent), which showed relatively higher fluctuations. As evident from Table 2, the area effect contributed 110,185,723 nuts (63.19 per cent) of the total increase in production, making it the largest contributor to output growth. The productivity effect contributed 39,934,711.44 nuts (22.90 per cent), while the interaction effect accounted for 24,261,061.92 nuts (13.91 per cent). Thus, the increase in Coconut production was mainly attributed to the expansion of cultivated area, supported by improvements in productivity, resulting in a net increase of 174,381,496.36 nuts during the study period.

Conclusion

The present study examined the growth, instability and decomposition of area, production and productivity of Groundnut, Sesamum and Coconut in Theni district, Tamil Nadu, during 2003-04 to 2022-23. The results revealed contrasting growth patterns among the three crops. Groundnut recorded a decline in cultivated area (CGR: -1.65%), while production (1.88%) and productivity (3.70%) increased, indicating that improvements in yield offset the reduction in area. Sesamum exhibited positive growth in area (3.07%), production (3.99%) and productivity (0.90%), whereas Coconut showed positive growth in area (2.47%) and production (0.60%), despite a decline in productivity (-1.82%). The decomposition analysis indicated that productivity was the major contributor to production growth in Groundnut (343.99%) and Sesamum (82.85%), while expansion of cultivated area was the dominant factor in Coconut production (63.19%). The instability analysis revealed that Sesamum production (CDVI: 67.27%) was the most unstable, followed by Groundnut production (25.31%), whereas Coconut area (CDVI: 4.53%) was the most stable during the study period.

The findings highlight the need for improved crop varieties, precision nutrient management, efficient irrigation, integrated pest management and climate-smart agricultural practices to enhance productivity in Groundnut and Sesamum. For Coconut, emphasis should be placed on scientific orchard management, balanced fertilization and efficient water management to improve productivity and

References

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