Growth performance of Arbi (Colocasia esculenta) under Eucalyptus tereticornis-based agroforestry system in plains of Chhattisgarh

Introduction

Agroforestry systems have gained attention worldwide for their potential to enhance agricultural productivity while promoting environmental sustainability. Agroforestry systems integrate trees with crops and/or livestock on the same land, and have emerged as sustainable alternatives to conventional agriculture. These systems not only enhance productivity but also contribute to biodiversity conservation, soil health improvement, and climate resilience. One significant aspect of agroforestry is its impact on crop performance under the canopy of trees, influencing microclimate, soil properties, and nutrient availability. (Fahad et al.2022) [4] . Understanding its performance in agroforestry systems, particularly under Eucalyptus canopies, is crucial for optimizing agricultural production in such environments. The Eucalyptus-based agroforestry system stands out due to the unique characteristics of Eucalyptus trees, which provide multiple benefits such as timber and fuel wood production, soil improvement by minimise soil erosion and water logging condition, carbon sequestration and other ecosystem services. (Nair, 1993; Jose, 2009; Leakey, 2014) [8,6,7] . Colocasia esculenta, commonly known as taro originated in South Central Asia, probably in India or Malaysia. It is a staple crop in many tropical and subtropical regions, valued for its edible corms and leaves valued for its tolerance to waterlogged conditions and adaptability to diverse agroecological settings. The growth performance of Colocasia esculenta in agroforestry systems can be influenced by various factors, including light availability, microclimatic conditions, nutrient cycling, and root competition with tree species. Understanding these dynamics is crucial for optimizing agricultural production while minimizing environmental impacts. Studies have shown that under the canopy of Eucalyptus trees, microclimatic conditions such as light intensity and temperature fluctuate, which can affect the growth, development, and yield of taro plants. This research seeks to investigate how Colocasia esculenta responds and interacts with Eucalyptus trees in agroforestry settings. The interaction between Colocasia esculenta and Eucalyptus trees involves complex mechanisms that affect growth, yield, and quality attributes of the crop. By assessing these factors, we aim to provide insights into the agronomic potential and ecological implications of integrating Colocasia esculenta within Eucalyptus plantations In recent years, researchers have explored the potential of integrating Colocasia esculenta into Eucalyptus-based agroforestry systems to leverage the synergistic interactions between trees and crops. Key objectives include assessing growth parameters such as plant height, leaf area index, leaf length, leaf width and number of leaf, as well as evaluating physiological responses related to photosynthesis, water use efficiency, and nutrient uptake. Additionally, the study aims to quantify taro growth and quality attributes under varying degrees of shading and proximity to Eucalyptus trees.Such knowledge is essential for sustainable agriculture practices, promoting food security, and harnessing the synergistic benefits of tree-crop interactions in agroforestry systems. By elucidating the performance of Colocasia esculenta in Eucalyptus-based agroforestry systems, this research contributes to broader efforts in sustainable agriculture and resource management. The findings will not only inform farmers and practitioners about the potential benefits and challenges of integrating taro with Eucalyptus but also offer insights into optimizing agroforestry practices for enhanced productivity and ecological resilience.

Materials and Methods

The experiment was conducted at Raipur, situated in the south eastern region of Chhattisgarh, India, at coordinates 21°23'39.77''N latitude and 81°69'44.30''E longitude, with an elevation of 295 meters above mean sea level. The study commenced in July 2019, with the crop being harvested in March 2020. A factorial randomized block design was employed, incorporating two colocasia varieties (V1: Indira Arbi-1 and V2: Arbi CG-2) intercropped with eucalyptus trees spaced 6 m × 6 m apart. The colocasia plants were arranged at a spacing of 50 cm × 30 cm. Fertilizer application was carried out in three phases: an initial basal dose comprising half the nitrogen (N), half the potassium (K), and all the phosphorus (P), followed by two subsequent split applications of the remaining nitrogen and potassium-one-fourth at 30 days after sowing (DAS) and another one-fourth at 60 DAS. Irrigation was initiated immediately after sowing to enhance germination, with subsequent watering provided based on soil moisture levels and seasonal rainfall patterns. The experimental field comprised black clayey soil classified as Vertisols, locally referred to as Kanhar. The soil was notably rich in organic carbon and essential nutrients, largely attributed to the annual deposition of organic matter from litterfall.

Statistical analysis

The data of all parameters of Colocasia collected precisely was tabulated, computed and statistical analysis done by using wordexcel spreadsheet a open factorial randomize block design. The growth parameters data of eucalyptus height and DBH were summarized with standard deviation and presented

Microclimatic Observations

The Microclimatic observation such as, Temperature (℃), Relative humidity (%) PAR (µ mol s -1 m -2) were recorded every fifteen days interval, by using Digital Thermometer, Digital Hygrometer and LICOR photo quantum meter respectively at three different timings in i.e. Morning, Noon and Evening hours in each plot of colocasia crop.

Results and Discussion

Growth parameters of coclocasia crop 1. Growth parameter

The growth parameters of colocasia viz; Plant height (cm), Number of leaves (leaves plant -1,) , leaf length (cm), leaf width (cm) and leaf area index are observed during the course of investigations are presented in Table 1-Table 5. The results reveal that growth parameters such as plant height, number of leaves plant -1, leaf length, leaf width and leaf area index affected non significantly by source of fertilizer treatment. Analysis of variance by source of variety revealed that plant height, number of leaves plant -1, leaf length, leaf width and leaf area index showed significantly effect by source of variety. Analysis of variance of source Treatment × Variety interaction showed non significant effect for all yield parameters

The study revealed that fertilizer treatment significantly increased colocasia plant height (P < 0.05) at key growth stages (Table -1), with the highest height observed in T-1 (fertilizer) at 165 DAS (80.03 cm) compared to T-2 (78.25 cm). Early growth (30 DAS) also showed greater heights in T-1 (23.44 cm) than T-2 (20.36 cm). Varietal effects were significant at most growth stages, with Indira Arbi-I (V-1) consistently outperforming Arbi CG-II (V-2) in plant height. At 165 DAS, V-1 reached 83.10 cm, while V-2 was 75.18 cm. V-1 also exhibited a faster growth rate throughout the experiment. The interaction between fertilizer and variety was statistically significant (P < 0.05), the T-1 × V-1 combination resulted in the highest plant height (84.78 cm), highlighting the combined benefit of fertilizer and superior variety.

Height of colocasia plants is found highest with fertilizer treatment as compare to growth without fertilizer whether it was found maximum in V-1 and minimum in V-2 this might be due to nutrient availability into the soil and genetic variability of different variety. Similarly Rajeskumar and Vijoykumar, (2001) [11] reported that the highest plant height was (74.40 cm) recorded with 120 kg N/ha. in colocasia. Pant et al. (2010) [9] also found that nitrogen application improve growth of colocasia crop when grown under poplar (Populous deltoids) based agroforestry system. Choudhary et al. (2011) [2] reported variation in plant height among different taro cultivar/ variety when grown under different agroclimatic conditions. Overall, fertilizer treatment consistently resulted in a higher number of leaves per plant. Variety significantly influenced the number of leaves at specific growth stages (75, 90, 105, 120, and 180 DAS), but differences were non-significant at 30, 45, 60, 135, 150, and 165 DAS. At 165 DAS, Indira Arbi-I (V-1) had a slightly higher number of leaves (9.25) than Arbi CG-II (V-2) (9.23). Early growth stages showed minimal and non-significant variation between varieties. The interaction between fertilizer and variety was mostly non-significant, except at 135 DAS. The highest number of leaves was observed in the T-1 × V-1 combination (9.54), followed by T-1 × V-2 (9.50), and the lowest in T-2 × V-2 (8.96). Combinations involving fertilizer consistently outperformed those without fertilizer across the experiment Number of leaf per plant is highest with fertilizer treatment as compare to without fertilizer, whether it was found in V-1and minimum in V-2. The difference in number of leaves per plant might be due to the genetic variation of crop reported by Paul and Bari, (2011) [10] and nutrient uptake capacity by colocasia varieties. Similarily improvement in number of leaf per plant by application of nitrogen fertilizer also reported by Pant et al.

(2010) [9] . The difference in number of leaves per plant in different colocasia variety were also reported by Dwivedi and Sen (2001) [3] , Rao et al. (2008) [12] and Choudhary et al. (2011) [2] .

The leaf length of colocasia (Table -3) was significantly influenced by fertilizer treatment (P < 0.05) at multiple growth stages (30, 45, 135, 150, 165, and 180 DAS) but not at others (60, 75, 90, 105, and 120 DAS). At 165 DAS, the maximum leaf length was observed in T-1 (31.73 cm) compared to T-2 (31.10 cm). Early growth (30 DAS) also showed higher leaf length in T-1 (7.30 cm) than T-2 (7.08 cm). Overall, leaf length was consistently greater under fertilizer treatment. Varietal effects on leaf length were statistically significant (P < 0.05) at key growth stages (30, 45, 60, 90, 150, 165, and 180 DAS). At 165 DAS, Indira Arbi-I (V-1) exhibited the maximum leaf length (33.04 cm) compared to Arbi CG-II (V-2) (29.79 cm). During early growth (30 DAS), V-1 recorded 8.21 cm, while V-2 measured 6.20 cm. Indira Arbi-I consistently showed greater leaf length throughout the experiment. The interaction between fertilizer and variety was not statistically significant but demonstrated the highest leaf length in the T-1 × V-1 combination (33.40 cm), followed by T-2 × V-1 (32.68 cm), with the lowest in T-2 × V-2 (29.52 cm). Interactions involving fertilizer consistently outperformed those without it. Varietal effects on leaf width were significant (P < 0.05) at 45, 60, 75, and 105 DAS but non-significant at later stages. At 165 DAS, Indira Arbi-I (V-1) had the highest leaf width (28.74 cm) compared to Arbi CG-II (V-2) (27.59 cm). During early growth (30 DAS), V-1 recorded 6.14 cm, while V-2 measured 5.91 cm. Indira Arbi-I consistently showed greater leaf width than Arbi CG-II. The interaction between fertilizer and variety was statistically non-significant. However, the highest leaf width was observed in T-2 × V-1 (29.22 cm), followed by T-1 × V-1 (28.26 cm), with the lowest in T-2 × V-2 (25.66 cm). Interactions involving fertilizer showed improved leaf width compared to those without it.

Length and width of leaf found more with fertilizer treatment as compare to without fertilizer and also found highest leaf length & width in V-1 than V-2. It may be due to presence of rich nutrients in soil, nutrient uptake capacity of varieties, availability of optimum sunlight and temperature to shade loving plant colocasia under eucalyptus & genetic variability. similarily Bhuiyan et al.( 2012) [1] also reported that nutrients is important for better growth of leaves under 25-30% shade [5] also observed the maximum LAI in all the cases of inorganic fertilizer application.

Conclusion

The result revealed that highest yield was obtained 118.66 qha -1 in fertilizer treatment and lowest 104.12 qha -1 in T 2 where no fertilizer was used, which was reduced by 12.06% with statistically significant variation .In case of variety Indira Arbi-I produced better yield 114.286 q ha -1 as compare to Arbi-CG-II which produced 108.1 q ha 1-with non significant variation. The crop registered better growth and yield performance in T 1 (RDF) treatment, while variations under established Eucalyptus plantations was found, The cultivation of colocasia as cover crop showed better growth & yield performance, while the farmer can get extra income on harvesting of Eucalyptus. Thus Eucalyptus + Colocasia farming was found beneficial in economical point of view. Overall In this experiment colocasia crop showed better results for variety Indira Arbi-I thus it can be acceptable for cultivation as cover crop under AFS to generate Income.

Future scope

Further intensive research work about intercropping management practices with different fertilizer doses under different tree species will required. Also the study of microclimatic as well as bio-parameters under the intercropping land utilization program required for more effective recommendation of intercropping management practices.

Acknowledgement

AcknowledgementThe authors are thankful to the members of my advisory committee, Dr. M. N. Naugraiya (Professor -Forestry), College of Agriculture, Raipur for their valuable advises and suggestions for improving this manuscript. Without their kind co-operation it would have not been easy for me to complete this manuscript.

References

1. Bhuiyan MM, Roy S, Sharma PC, Rashid MH, Bala P. Impact of multistoreyed agroforestry systems on growth and yield of turmeric and ginger at Mymensingh, Bangladesh. Crop Prod. 2012;1(1):19-23.
2. Choudhary VK, Kumar PS, George J, Kanwat M, Saravanan R. Genetic variability and character association in taro (Colocasia esculenta (L.) Schott.) under Mid-Hills of Arunachal Pradesh. J Root Crops. 2011;37(2).
3. Dwivedi AK, Sen H. Comparative study of some local taro (Colocasia esculenta var. antiquorum) cultivars of West Bengal. Hortic J. 2001;14(2):149-55.
4. Fahad S, Chavan SB, Chichaghare AR, Uthappa AR, Kumar M, Kakade V, et al. Agroforestry systems for soil health improvement and maintenance. Sustainability. 2022;14(22):14877. doi:10.3390/su142214877.
5. Hossain D, Ullah M, Shahjahan M, Haque MA, Ali M. Effects of organic and inorganic fertilizers on yield and yield-contributing characters of mukhi kachu (Colocasia esculenta L.). Agriculturists. 2009;7(1-2):50-6.
6. Jose S. Agroforestry for ecosystem services and environmental benefits: An overview. Agrofor Syst. 2009;76(1):1-10. doi:10.1007/s10457-009-9229-7.
7. Leakey RRB. Agroforestry: A delivery mechanism for multifunctional agriculture. In: Leakey RRB, editor. Tropical Agriculture and Sustainable Development. Springer; 2014. p. 29-50.
8. Nair PKR. An Introduction to Agroforestry. Dordrecht: Kluwer Academic Publishers; 1993.
9. Pant KS, Mishra VK, Sanwal CS, Dinssa KU. Effect of nitrogen and poplar spacing on yield and nutrient content of taro (Colocasia esculenta L.). Indian J Agrofor. 2010;12(1).
10. Paul KK, Bari MA. Accession characterization and genetic variability studies in Colocasia esculenta L. Schott. Bangladesh J Sci Ind Res. 2011;46(2):235-42. doi:10.3329/bjsir.v46i2.8191.
11. Rajeskumar, Vijoykumar. Response of nitrogen, potassium and spacing on growth and yield of arvi (Colocasia esculenta (L.) Schott). J Root Crops. 2001;27(1):254-7. http://archive.saulibrary.edu.bd:8080/xmlui/handle/1234567 89/4946
12. Rao BN, Roy SS, Devi YI, Lavid P, Singh SG. Colocasia germplasms of Manipur: a performance analysis. In: Proceedings of the Third Indian Horticulture Congress; 2008. p. 140-1.