Effect of nano and ordinary urea on growth, yield and economics of elephant foot yam [Amorphophallus paeoniifolius (Dennst.) Nicolson]

Introduction

Elephant Foot Yam [Amorphophallus paeoniifolious (Dennst.) Nicolson)] is an important tuber crop grown in Bihar particularly in the districts of northern Bihar. It is also one of the most important tuber crops of India as well as other parts of the tropical and subtropical world. In the present situation of changing climate scenario, it has assumed more importance than before due to some unparalleled edges over other crops like-its capacity to produce even in adverse climatic conditions without affecting much on its productivity and its high yield potential (George James and Sunitha, S., 2018) [3] . Its farming is also eco-friendly because of less use of agro-chemicals (Singh et al., 2020) [9] . It has both nutritional and medicinal value and is usually consumed as cooked vegetable. Elephant foot yam is rich in minerals, protein, vitamins-A. (Mukherjee et al., 2020) [6] . It has high dry matter production capability per unit area than most of the other vegetables. Elephant foot yam is a remunerative and profitable tuber crop. The crop is gaining popularity due to easiness in cultivation, high productivity, less incidence of pests and diseases, steady demand and reasonably good price. Tubers are mainly used as vegetable after thorough cooking. There are several factors responsible for increase in cost of production of crops especially elephant foot yam and among them are-chemical fertilizers particularly most commonly used nitrogenous fertilizer like-urea. Use of urea as nitrogenous fertilizer becomes even costlier due to its low nitrogen use efficiency, less net assimilation rate, its potential losses like leaching, volatilization along with air, water and environmental hazards. Keeping these views, it was thought to go for other nitrogenous fertilizer like nano urea which have an edge over ordinary urea with the objectives-to reduce the cost of production by reducing the doses of ordinary urea and address the concerns with ordinary urea and most importantly, the effect of nano urea on growth, yield and economics on cultivation of elephant foot yam.

Materials and Methods

The experiment was conducted at Agricultural Research Farm, Dholi of Tirhut College of Agriculture under Dr. Rajendra Prasad Central Agricultural University, Pusa (Bihar) during the period of 2024-25 to 2025-26. The soil of the experimental plot was sandy loam with pH value of 8.2. Initial soil analysis value of experimental field was: available nitrogen (201.6 kg/ha), phosphorus (16.1 kg/ha), and potassium (128.4 kg/ha). There were five treatments i.e.,T 1: As per package of practices of the state (15 t FYM/ha and 80:60:80 Kg N:P 2 O 5 :K 2 O/ha); T 2: IFFCO nano urea (4% N) as foliar spray [ similar operation as in T 1 except two sprays of nano urea as foliar in place of 50% nitrogen through ordinary urea in soil at one & two month after planting]; T 3: [ similar operation as in T 1 except two sprays of 2% ordinary urea as foliar in place of 50% nitrogen through ordinary urea in soil at one & two month after planting]; T 4: T 1 + two sprays of nano urea as foliar spray at one and two month after planting and T 5: T 1 + 2% ordinary urea in two foliar sprays at one and two month after planting. In T 1 , 50% of nitrogen and potassium along with 100% phosphorus was applied as basal dose and 50% of remaining nitrogen and potassium was applied in two equal split of top dressing at one and two month after planting. Basal application of nitrogen, phosphorus, potassium and top dressing of 50% of potassium was kept same for all treatments. There were only variations in doses, application methods and source of nitrogen for remaining 50% nitrogen in different treatments. 'Gajendra' was taken as test variety. Pseudostem height, pseudo stem girth, canopy spread of five tagged plants were recorded treatment and replication wise at three and five months after planting and were averaged. Similarly, corm weight of five plants was taken after harvesting and cleaning of corms and then were calculated on hectare basis (t/ha). All other standard package of practices were followed and analysis was done following standard statistical procedures.

Results and Discussion

Different treatments of nitrogen application either in the form of ordinary urea or nano urea produced significant effect on pseudostem height, pseudo-stem girth and canopy spread. It was found that pseudo-stem height under T 4 treatment where two extra sprays of nano urea in addition to package of practices of manures and fertilizers of the state was given at one and two months after planting was significantly superior over T 2 and T 1 and was found at par with T 3 where 2% ordinary urea as foliar spray was given in place of nano urea foliar application and T 5 -where 2% ordinary urea was foliar applied in addition to package of practices of manures and fertilizers of the state. Reduction in the pseudo-stem height was to the tune of 2.91 to 11.29 and 2.25 to 11.36 per cent as compared to other treatments at 3 and 5 months after planting. Similarly, reductions in pseudo stem girth at 3 and 5 months after planting were to the tune of 1.22 to 8.88 and 2.19 to 9.66 per cent and for canopy spread it ranged from 2.74 to 11.84 and 1.13 to 10.80 per cent, respectively. Pseudo-stem height after five months of planting followed similar trend where only T 5 showed comparable result on pseudo-stem height to that of T 4 . Significantly lower pseudo-stem height was recorded under T 2 treatment where only two foliar sprays of nano urea was applied for 50% nitrogen application as top dressing in two splits may be due to lesser amount of nitrogen available for plants as compared to other treatments; although the nitrogen use efficiency of nano urea is very high as compared to ordinary urea. Nitrogen is a vital macronutrient required for the synthesis of amino acids, proteins, chlorophyll and cell membranes. Adequate nitrogen availability enhances photosynthetic activity, promotes vigorous vegetative growth and supports overall plant development (Krishnaveni and Ramaswamy, 1985) [5] . Pseudo-stem girth and canopy spread recorded after three and five months after planting produced similar patterns of results to that of pseudo-stem height may be due to lesser quantity of nitrogen available to plants and overall lesser quantity of nitrogen absorbed by the plants under T 2 (Table -1. & Fig. -1). Similar findings were also reported by Neogi S. and Das S.K. (2022) [7] , Dutta et al. (2023) [1] and Hoque and Khan in potato (2024) [2] . Net return and B:C ratio were also significantly influenced by different treatments of nitrogen application either in the form of soil application or foliar application through the different sources of nitrogen (ordinary urea and nano urea). Corm yield/plant (kg), corm yield (t/ha), net return and B:C ratio were also significantly influenced by the application of nitrogen either in the form of nano urea or ordinary urea applied in the soil or as foliar application. It was found that corm yield per plant and on hectare basis in T 4 was significantly higher than T 2 and T 1 and was found at par with T 5 and T 3 . The reduction in T 2 was to the tune of 2.93 to 10.18 and 3.46 to 8.39 per cent for corm yield per plant and corm yield on hectare basis, respectively may be due to the cumulative effect of growth conditions of the plant in different treatments and availability and absorption of nitrogen due to different methods of application of nitrogen in the soil or in the form of foliar apllication of nano urea or ordinary urea (Table-2. & Fig. -2). These results conform the findings of Shivam Kumar et al (2025) [8] on tomato where maximum fruit yield per plant

(1.90 kg), per plot (56.84 kg) and per hectare (438.66 q) were recorded in 100% RDN + two sprays of nano urea @ 4 ml/litre at 30 and 50 DAT and also similar results were reported by Sneha et al. (2026) and Karubakee in potato (2024) [4] . It was found that net return under T 4 treatment where two extra sprays of nano urea in addition to package of practices of manures and fertilizers of the state (was given at one and two months after planting) was significantly superior over T 2 and was found at par with rest of the treatments. Effects due to different treatments of nitrogen in the form of nano urea or ordinary urea also influenced B:C ratio in the same pattern to that of net return. Reduction in the net return under treatment T 2 was to the tune of 6.42 to 14.38 as compared to other treatments. Similarly, reductions in B:C ratio was to the tune of 3.93 to 8.39. treatments. Similar findings were also reported by Neogi and Das (2022) [7] in potato.

Conclusion

Based on the findings of this experiment it can be concluded that the treatment of two foliar applications of nano urea (4% N) to replace 50% nitrogen dose (T 2 ) which is used as top dressing at one and two months after planting of elephant foot yam in the soil resulted in reduction of pseudo-stem height, pseudo-stem girth, canopy spread, corm yield/plant (kg), corm yield (t/ha), net return (Rs./ha) and B:C ratio of elephant foot yam as compared to the treatment of package of practices of manures and fertilizers of the state (T 1 ) but all these growth, yield and economic parameters mentioned above under T 4 treatment where two extra sprays of nano urea in addition to package of practices of manures and fertilizers of the state was given at one and two month after planting was significantly superior over T 2 with respect to all these growth, yield and economic parameters mentioned above.

References

1. Dutta D, Bhattachrya P, Sengupta K, Das D. Effect of nano urea on growth and yield of potato in lower Gangetic plains of West Bengal. Journal of Eco-friendly Agriculture. 2023;18(2):266-268.
2. Hoque MR, Khan MSH. Greater growth and yield response of nano urea with conventional urea for potato (Solanum tuberosum) cultivation. International Journal of Biological Engineering and Agriculture. 2024;3(3):378-385.
3. George J, Sunitha S. Tropical tuber crops: potential and prospects. New Delhi: Westvill Publishing House; 2018. p. 1-11.
4. Karubakee S. Effect on yield, nutrient uptake and quality of potato (Solanum tuberosum L.) under integrated nutrient management. Notulae Botanicae Horti Agrobotanici ClujNapoca. 2024;52(1):13288.
5. Krishnaveni K, Ramaswamy KR. Influence of N, P and K on the yield and yield attributes of CH-1 hybrid. Madras Agricultural Journal. 1985;72(7):382-387.
6. Mukherjee A, Sheela I, Prakash P, Jaganathan D, Sivakumar PS. Root and tuber crops: life saving future crops. Kerala Karshakan e-Journal. 2020 Jun:27-33.
7. Neogi S, Das SK. Effect of nitrogen and zinc in nano forms on growth and productivity of potato (Solanum tuberosum L.) in Inceptisols. Journal of Crop and Weed. 2022;18(1):3238.
8. Kumar S, Rajiv, Tripathi VK, Kushwaha V, Kumar D. Effect of nano urea on growth, yield and quality of tomato (Solanum lycopersicum L.) cv. Azad T-6. International Journal of Research in Agronomy. 2025;8(8):667-670.
9. Singh RS, Narayan A, Kumar A, Chaudhary CS, Pandey IB. Effect of integrated weed management practices on weed dynamics, growth, yield and economics of elephant foot yam [Amorphophallus paeoniifolius (Dennst.) Nicolson]. Plant Archives. 2020;20(Suppl 2):1242-1245.
10. Math SP, Hiremath SM, Shashidhar TR, Rajkumara S. Effect of nano urea on growth, yield and economics of potato (Solanum tuberosum L.). Plant Archives. 2026;26(Suppl 1):2296-2300.