Assessment of shoot biomass, dry matter content and tuber productivity in potato genotypes propagated through apical rooted cuttings

Introduction

Potato (Solanum tuberosum L.) is one of the most widely cultivated and economically important food crops in the world, playing a crucial role in food security and the livelihoods of millions of farmers. In India, potato cultivation has expanded significantly, contributing to both subsistence and commercial agriculture. However, the traditional method of potato propagation through seed tubers comes with challenges such as high seed cost, susceptibility to diseases and the bulkiness of seed tubers, which makes storage and transportation difficult. To address these challenges, alternative propagation methods like apical rooted cuttings (ARCs) have been introduced, offering potential advantages in reducing seed costs and improving disease management. Apical rooted cuttings are gaining attention as a viable alternative to tuber propagation due to their cost-effectiveness and potential to reduce disease transmission. Unlike seed tubers, ARCs involve using vegetative parts of the plant that are rooted and transplanted into the field. This method allows farmers to reduce the quantity of seed material required, thereby lowering input costs. Additionally, ARCs offer the potential for faster multiplication rates, making it easier for farmers to access high-quality planting material. However, despite these advantages, there is still limited research on how different potato genotypes perform when propagated through ARCs compared to traditional seed tubers in terms of growth, yield and economic returns. This comparative study aims to evaluate the growth, yield and economics of various potato genotypes propagated through apical rooted cuttings and seed tubers. By analyzing key parameters such as plant height, number of shoots, tuber yield and marketable yield, this study seeks to determine the viability of ARCs as an alternative propagation method. Furthermore, the study will assess the economic implications of using ARCs versus seed tubers, providing valuable insights for farmers and stakeholders in optimizing potato production practices to improve both productivity and profitability.

Material and methods

The field experiment was conducted at the E-Block, Main Agricultural Research Station (MARS), Dharwad, during the Kharif season of 2023 to evaluate the performance of potato genotypes propagated through apical rooted cuttings (ARCs). The experimental setup followed a Randomized Block Design (RBD) with three replications. Eight potato genotypes were studied, including Kufri Jyoti, Kufri Lima, Kufri Chipsona-4 and Kufri Sangam, propagated through ARCs, while Kufri Jyoti propagated through tubers served as the check. The experimental plots were established with a spacing of 60 x 20 cm and each plot measured 3 m x 3 m.

For growth parameter analysis, key observations like plant height, the number of primary shoots, the number of compound leaves and Fresh weight of shoots per plant, dry weight of shoots per plant, dry matter content of plant were recorded. Five plants were randomly selected and tagged in each plot and data were collected at different growth stages to assess the performance of each genotype. The tuber weight, average tuber weight and number of tubers per plant were measured after harvesting. All these parameters were used to assess the impact of different propagation methods on the vegetative and reproductive growth of potato plants. Yield and economics data were also recorded post-harvest. Total tuber yield per plot and hectare, marketable yield per plot and hectare were calculated. Economic analysis involved determining the net returns and benefit-cost (B:C) ratio based on the cost of cultivation and marketable produce. The statistical analysis was performed using ANOVA to test the significance of differences between genotypes and propagation methods for each recorded parameter.

Results and Discussion

The plant height, number of shoots per plant, number of compound leaves per plant, Fresh weight of shoots per plant, dry weight of shoots per plant, dry matter content of plant, number of tubers per plant, weight of tubers per plant, average weight of tuber per plant, total yield per plot, total yield per hectare, marketable yield per plot, marketable yield per hectare, gross returns, net returns and benefitcost ratio (B:C ratio) for several potato genotypes was calculated. The data regarding growth and yield parameters is presented in Table 1, 2 and 3.

Plant height

The plant height ranged from 35.24 cm to 46.82 cm. The highest plant height was recorded in Kufri Jyoti (46.82 cm) propagated through tubers, followed by Kufri Lima (45.97 cm) and Kufri Sangam (45.56 cm). The lowest height was observed in Kufri Jyoti propagated through apical rooted cuttings (35.24 cm). The significant variation in plant height among the potato genotypes highlights the influence of propagation methods on vegetative growth. Kufri Jyoti, propagated through tubers recorded the maximum height (46.82 cm), indicating its vigorous growth when using traditional seed tubers. This could be attributed to better initial nutrient reserves and root development. In contrast, Kufri Jyoti propagated through apical rooted cuttings (ARC) showed the lowest plant height (35.24 cm), which suggests that ARCs may experience slower initial growth due to delayed root establishment. These findings are consistent with previous studies that indicate slower growth in ARC-propagated plants during early stages. Similar variations in plant height with respect to potato genotypes was noticed by Abdalla et al. (2022) [1] and Kumar et al. (2023b) [2] .

Number of primary shoots per plant

The number of primary shoots varied from 1.89 to 4.99. Kufri Jyoti propagated through tubers recorded the highest number of shoots (4.99), while the lowest was in Kufri Jyoti propagated through apical rooted cuttings (1.89). The number of primary shoots per plant is crucial for determining the plant's ability to produce tubers. Kufri Jyoti propagated through tubers had the highest number of shoots (4.99), reflecting its superior vegetative capacity. However, Kufri Jyoti propagated through ARCs recorded the lowest (1.89), which is likely a result of limited shoot development in ARCs compared to tubers. This suggests that tuber propagation provides a better environment for shoot initiation due to the presence of auxiliary buds and stored energy in the tubers. Similar variations in number of primary shoots/plant with respect to potato genotypes was observed by Ranalli et al. (1994) [3] and Rajegowda et al. (2021) [4] .

Number of compound leaves per plant

The number of compound leaves ranged between 25.11 and 41.84. Kufri Jyoti (41.84) propagated through tubers showed the highest leaf count, on par with Kufri Lima (38.54), while Kufri Jyoti propagated through apical rooted cuttings (25.11) recorded the lowest. The num-ber of compound leaves is directly related to the photosynthetic potential of the plant. Kufri Jyoti (tuber) showed the highest number of compound leaves (41.84), which may have contributed to its higher yield by providing more surface area for photosynthesis. The lower leaf count in Kufri Jyoti propagated through ARCs (25.11) indicates reduced vegetative growth, which aligns with the slower shoot and root development observed in ARC-propagated plants. These differences suggest that propagation methods significantly affect foliage development. Similar differences in number of compound leaves/plant were reported with respect to potato genotypes by Sharma et al. (2020) [5] and Kumar et al. (2021) [6] .

Fresh weight of shoots per plant

At 75 days after transplanting, the fresh weight of shoots per plant of different potato genotypes under the investigation varied significantly ranging from 65.01 to 129.34 g with an average mean value of 90.54 g. Of all the genotypes, the tuber-propagated Kufri Jyoti had significantly highest fresh weight of shoots per plant (129.34 g), which was statistically on par with the apical rooted cutting-propagated Kufri Lima (122.56 g). The Kufri Karan which was propagated using apical rooted cuttings, had significantly lowest fresh weight of shoots per plant (65.01 g). The observed variance in fresh weight of shoots per plant among potato genotypes demonstrates the impact of both genotype and propagation strategy. The tuber-propagated Kufri Jyoti had significantly highest fresh weight of shoots per plant (129.34 g), indicating greater biomass growth, possibly because to the intrinsic vigor associated with tuber propagation. Interestingly, Kufri Lima grown using apical rooted cuttings had a comparable fresh weight (122.56 g), suggesting that this approach is equally successful as traditional tuber propagation in some genotypes. Kufri Karan, which was likewise produced through apical rooted cuttings, had the lowest fresh weight (65.01 g), which might be attributable to either genetic features or a less efficient adaptation to this propagation method. Similar variations in the fresh weight of shoots per plant were discovered among potato genotypes by Lommen et al. (1994) [7] .

Dry weight of shoots per plant

Significant differences were observed for dry weight of shoots per plant which was ranged between 20.87 to 28.60 g with an average mean value of 23.85 g. Of all the genotypes, the tuber-propagated Kufri Jyoti recorded significantly highest dry weight of shoots per plant (28.60 g), which was statistically on par with the apical rooted cutting-propagated Kufri Lima (25.95 g) and it was followed by Kufri Sangam (25.13 g). The Kufri Karan (20.87 g), which was propagated using apical rooted cuttings, had significantly lowest dry weight of shoots per plant. The difference in dry weight of shoots per plant across potato genotypes demonstrates the impact of propagation strategies on plant biomass. The tuber-propagated Kufri Jyoti had the maximum dry weight (28.60 g), which was statistically equivalent to the apical rooted cutting-propagated Kufri Lima (25.95 g). This resemblance shows that apical rooted cuttings can yield shoot biomass comparable to classical tuber propagation, making them a viable alternative propagation strategy. However, the lowest dry weight recorded in Kufri Karan (20.87 g), which was also reproduced via apical rooted cuttings, suggests that genotype-specific responses to propagation strategies exist. The lack of substantial variations in dry weight between genotypes, including the best-performing Kufri Jyoti, implies that growth potential is consistent independent of propagation method and growth parameters. Potato genotypes showed similar variability in the dry weight of shoots per plant as noticed by Kumar et al. (2021) [6] .

Dry matter content of the plant

At 75 days after transplanting (DAT), the dry matter content of the plant of several potato genotypes varied significantly with an average mean value of 27.14 per cent ranging from 21.18 to 32.10 per cent. Of all the genotypes, Kufri Karan (32.10 per cent) propagated through apical rooted cuttings had significantly highest dry matter content of the plant, which was statistically on par with the apical rooted cutting-propagated Kufri Chipsona-4 (29.08 per cent), Kufri Jyoti (29.04 per cent) and Kufri Sangam (28.64 per cent). The Kufri Lima which was propagated using apical rooted cuttings had significantly lowest dry matter content of the plant (21.18 per cent). The variation in dry matter content among different potato genotypes observed in this study at 75 days after transplanting aligns with the findings of Kumar et al., (2019) [8] and Singh et al. (2020b) [9] . The high dry matter content in genotypes like Kufri Karan (32.10%) and Kufri Chipsona-4 (29.08%) propagated through apical rooted cuttings suggests that these genotypes have better resource allocation towards biomass accumulation. This may be due to their genetic predisposition towards efficient nutrient uptake and utilization, which is critical for tuber quality and yield. In contrast, Kufri Lima exhibited the lowest dry matter content (21.18%), potentially indicating less efficient nutrient utilization or a genetic trait associated with lower biomass accumulation. These results underscore the importance of genotype selection for optimizing potato production through apical rooted cuttings.

Number of tubers per plant

The number of tubers per plant varied from 1.93 to 6.80. The highest was recorded in Kufri Jyoti (6.80) propagated through tubers, while the lowest was observed in Kufri Karan (1.93) propagated through apical rooted cuttings. Kufri Jyoti (tuber) recorded the highest number of tubers per plant (6.80), demonstrating that tuber propagation promotes superior reproductive growth. The lowest number of tubers was observed in Kufri Karan (1.93) propagated through ARCs, which suggests that ARC propagation may limit tuber formation in some genotypes. This could be due to reduced early growth, affecting the plant's capacity to develop multiple tubers. Similar variations in number of tubers per plant was observed by Rajegowda et al. (2021) [4] , Sharma et al. (2020) [5] and Patel et al. (2019) [10] .

Weight of tubers per plant

Tubers' weight ranged between 70.04 g and 290.15 g. Kufri Jyoti (290.15 g) propagated through tubers recorded the highest tuber weight, while Kufri Chipsona-4 (70.04 g) had the lowest. The weight of tubers per plant varied significantly, with Kufri Jyoti propagated through tubers recording the highest (290.15 g). This result highlights the advantage of tuber propagation in enhancing tuber development and overall biomass. The lowest tuber weight was found in Kufri Chipsona-4 (70.04 g), suggesting poor tuber growth in this genotype under the given conditions, possibly due to genetic limitations. The findings are consistent with those revealed by Giri et al. (2023) [11] and Kumar et al. (2023a) [12] .

Average weight of tubers

The average tuber weight ranged from 32.86 g to 42.67 g. Kufri Jyoti (42.67 g) propagated through tubers recorded the maximum, while Kufri Himalini (32.86 g) propagated through apical rooted cuttings had the lowest. Kufri Jyoti propagated through tubers also had the highest average tuber weight (42.67 g), further supporting the effectiveness of this propagation method in promoting larger tubers. In contrast, Kufri Himalini propagated through ARCs had the smallest average tuber weight (32.86 g), indicating that ARC propagation may not be as effective in achieving optimal tuber size in certain genotypes which is consistent with Namugga et al. (2024) [13] and Khan et al. (2020) [14] observations. [15] . [16] . [17] .

Total yield per plot

Total yield per hectare

Marketable yield per plot

Marketable yield per hectare

Marketable yield per hectare ranged from 1.35 t/ha to 14.17 t/ha. Kufri Jyoti (14.17 t/ha) propagated through tubers recorded the highest, while Kufri Karan (1.35 t/ha) had the lowest. The marketable yield per hectare was highest in Kufri Jyoti propagated through tubers (14.17 t/ha), reinforcing its potential for commercial cultivation. The lowest marketable yield was observed in Kufri Karan (1.35 t/ha), which further highlights the limitations of ARC propagation for this genotype. Overall, tuber propagation consistently outperformed ARC propagation in terms of both total and marketable yield, suggesting that while ARCs offer certain advantages, tuber propagation remains the most reliable method for achieving high productivity in potato cultivation. Potato genotypes showed similar variability in the marketable yield noticed by Benz et al. (1995) [18] .

Gross returns

The genotype Kufri Jyoti propagated through tubers had the highest gross returns of 411146.72 Rs./ha. Among apical rooted cuttings propagated genotypes, Kufri Lima and Kufri Sangam, Kufri Mohan had higher gross returns of (239039.41 Rs./ha), (216136.75 Rs./ha) and (187364.32 Rs./ha). Kufri Karan propagated through apical rooted cuttings had the lowest gross returns (93482.91 Rs./ha). A similar trend was observed by Yadav et al. (2024) [19] for gross returns, where Kufri Jyoti, propagated via tubers, outperformed all other genotypes, recording the highest gross returns at Rs. 411,146.72/ha. This reflects the direct correlation between high yield and economic returns. Among the genotypes propagated through apical rooted cuttings, Kufri Lima, Kufri Sangam and Kufri Mohan demonstrated relatively higher gross returns of Rs. 239,039.41/ha, Rs. 216,136.75/ha and Rs. 187,364.32/ha, respectively. Kufri Lima, once again, emerged as the top-performing genotype among those propagated through apical rooted cuttings. In contrast, Kufri Karan exhibited the lowest gross returns at Rs. 93,482.91/ha, indicating that the low yield led to unsatisfactory economic outcomes for this genotype.

Net returns

The genotype Kufri Jyoti propagated through tuber had the highest net returns (256146.72 Rs./ha). Among the apical rooted cuttings genotypes, Kufri Lima, Kufri Sangam and Kufri Mohan had the higher net returns (114039.41 Rs./ha), (91136.75 Rs./ha) and (62364.32 Rs./ha). The genotype with lowest net returns (-31517.09 Rs./ha) was Kufri Karan propagated through apical rooted cuttings. The net returns further emphasized the superiority of Kufri Jyoti propagated via tubers, with the highest net returns of Rs. 256,146.72/ha. The genotypes propagated through apical rooted cuttings followed a similar ranking, with Kufri Lima showing the highest net returns of Rs. 114,039.41/ha, followed by Kufri Sangam at Rs. 91,136.75/ha and Kufri Mohan at Rs. 62,364.32/ha. The most notable outcome, however, was the negative net returns of Kufri Karan (-Rs. 31,517.09/ha), propagated through apical rooted cuttings, which not only had the lowest yield but also failed to cover the production costs. This result underscores the economic risks associated with Kufri Karan when propagated through apical rooted cuttings. Similar variations with respect to net returns was observed by Sinha et al. (2019) [20] and Lal et al. (2006) [21] .

Benefit: cost ratio (B:C ratio)

The genotype Kufri Jyoti propagated through tuber had the highest benefit: cost ratio (2.65). Among the apical rooted cuttings propagated genotypes, Kufri Lima, Kufri Sangam and Kufri Mohan had the higher benefit: cost ratio (1.91), (1.73) [22] and Chauhan et al. (2022) [23] .

Conclusion

The study reveals significant differences in growth and yield parameters among various potato genotypes when propagated through apical rooted cuttings (ARCs). Tuber propagation consistently outperformed ARC propagation across metrics such as plant height, number of shoots, leaves, stem diameter and tuber yield, with Kufri Jyoti showing superior growth potential and economic viability for large-scale cultivation. While ARC propagation reduces seed costs, it exhibited limitations in yield and plant vigor, particularly for genotypes like Kufri Karan. Kufri Lima, however, performed well under ARC propagation, indicating its potential for alternative methods. Overall, tuber propagation proved to be a more reliable approach for maximizing yield and economic returns, particularly with Kufri Jyoti, while Kufri Karan demonstrated poor performance across all parameters under ARC propagation. These findings offer valuable insights for farmers and agricultural stakeholders in selecting appropriate genotypes and propagation methods to optimize productivity and profitability in potato cultivation.

References

1. Abdalla N, El-Ramady H, Seliem MK, El-Mahrouk ME, Taha N, Bayoumi Y, Shalaby TA, Dobránszki J. An academic and technical overview on plant micropropagation challenges. Horticulturae. 2022;8(8):677.
2. Kumar S, Amruta SB. Validation of potato apical rooted cuttings for their performance under field conditions. The Pharma Innovation Journal. 2023;12(6):621-623.
3. Ranalli P, Bassi F, Ruaro G, Del Re P, Di Candilo M, Mandolino G. Microtuber and minituber production and field performance compared with normal tubers. Potato Research. 1994;37:383-391.
4. Rajegowda LKS, Bindu N, Dhamodhar GN, Pankaja HK, Shivashankar M, Nagaraja T, Deshwara A. Evaluation and introduction of apical rooted potato saplings in Hassan district. Environment and Ecology. 2021;39(4A):1074-1077.
5. Sharma S, Gupta R, Singh V. Effects of different propagation methods on potato yield. Journal of Agricultural Science. 2020;12(3):45-53.
6. Kumar P, Singh R. Enhanced potato productivity through apical rooted cuttings: A review. Potato Research Journal. 2021;3(1):581-584.
7. Lommen WJM, Struik PC. Field performance of potato minitubers with different fresh weights and conventional seed tubers: Crop establishment and yield formation. Potato Research. 1994;37:301-313.
8. Kumar P, Singh R. Dry matter accumulation and its impact on tuber quality in different potato genotypes. Journal of Crop Improvement. 2019;33(4):567-583.
9. Patel M, Rao S. Genotypic variation and its impact on potato tuber yield. Horticulture Research. 2019;8(1):89-97.
10. Giri RK, Upadhyay KP, Bhusal Y, Dhakal R, Subedi GD, Chalise B, Poudel B. Performance evaluation of nutrient dense potato genotypes at high hills of Karnali province, Nepal. Asian Journal of Advances in Agricultural Research. 2023;21(2):40-50.
11. Kumar S, Amruta SB. Standardization of spacing and varieties for production of tubers from apical rooted cuttings. The Pharma Innovation Journal. 2023;12(5):3621-3625.
12. Namugga P, Aijuka S, Arinda O, Mateeka B, Barekye A. Early generation seed starter materials and approaches to seed production: Challenge for improving the potato seed system in Uganda. Crop Science. 2024;64(3):1311-1319.
13. Khan AI, Hussain S, Zahoor M, Rasool G, Shah I. Effect of planting dates on the performance of apical rooted cuttings in potato (Solanum tuberosum L.). Journal of Agricultural Research. 2020;58(2):100-107.
14. Handayani T, Sahat JP, Pertiwi MD. The utilization of apical rooted cuttings for the seed production of potato varieties for processing. IOP Conference Series: Earth and Environmental Science. 2023;1(4):1172-012012.
15. Sushil SN, Sharma RC, Bahadur R. Impact of Apical Cuttings on Potato Growth and Yield Performance under Different Climatic Conditions. Journal of Agronomy. 2018;89(4):49-56.
16. Aarakit P, Ouma JP, Lelei JJ. Growth, yield and phosphorus use efficiency of potato varieties propagated from apical rooted cuttings under variable phosphorus rates. African Journal of Plant Science. 2021;15(7):173-184.
17. Benz JS, Keller ER, Midmore DJ. Planting materials for warm tropic potato production: growth and yield of transplanted seedlings or rooted cuttings and tuber materials in the field. Field Crops Research. 1995;40(3):179-192.
18. Yadav RS, Kushwaha R, Maurya K, Singh AK, Singh RK, Verma AK. A Study on Costs and Returns of Potato in Azamgarh District of Eastern Uttar Pradesh, India. Journal of Experimental Agriculture International. 2024;46(5):825-831.
19. Sinha AK, Singh SK. Economics of potato production in Northern hills of Chhattisgarh. Economic Affairs. 2019;64(1):1-7.
20. Lal H, Sharma KD. Economics of potato production in Lahaul valley of Himachal Pradesh. Potato Journal. 2006;33(3and4):139143.
21. Subedi S, Ghimire YN, Gautam S, Poudel HK, Shrestha J. Economics of potato (Solanum tuberosum L.) production in terrain region of Nepal. Archives of Agriculture and Environmental Science. 2019;4(1):57-62.
22. Chauhan B, Joshi D, Banjade D, Bhatta BD, Awasthi P, Paneru M, Shrestha M, Chand PB. Economics of potato (Solanum tuberosum L.) production and marketing in Darchula district of Nepal. Archives of agriculture and environmental science. 2022;7(3):393-401.