Effect of various levels of phosphorus and molybdenum on growth, yield attributes and yield of summer green gram (Vigna radiata L.)

Introduction

Green gram (Vigna radiata L.) is one of the most important pulse crops because of its high nutritional value, short duration, and capacity to improve soil fertility through biological nitrogen fixation. It is an excellent source of plant protein, carbohydrates, vitamins, minerals, and essential amino acids, making it an important component of human nutrition, particularly in developing countries (Hou et al., 2019; Movalia et al., 2018) [4,5] . Besides its nutritional significance, green gram contributes to sustainable agriculture by enriching soil fertility through its symbiotic association with Rhizobium, thereby reducing the dependence on chemical nitrogen fertilizers (Patel et al., 2013; Banerjee and Nath, 2022) [6,3] . However, despite its economic and nutritional importance, the productivity of green gram in India, including Haryana, remains below its potential due to poor soil fertility, nutrient deficiencies, and inadequate nutrient management practices. Among the essential plant nutrients, phosphorus and molybdenum play a pivotal role in improving the growth and productivity of pulse crops. Phosphorus is indispensable for root development, energy transfer, photosynthesis, nodulation, flowering, and seed formation, besides enhancing biological nitrogen fixation (Theodorou and Plaxton, 1993; Arsalan et al., 2016) [7,2] . Molybdenum, although required in trace amounts, is an integral component of the nitrogenase and nitrate reductase enzyme systems and is therefore essential for efficient nitrogen metabolism and symbiotic nitrogen fixation in legumes (Mendel and Hänsch, 2002; Westermann, 2005) [8,9] . Deficiency of molybdenum adversely affects nodule formation, nitrogen fixation, and plant growth, ultimately resulting in lower productivity (Rao and Singh, 1983; Sun et al., 2009) [10,11] . Although the beneficial effects of phosphorus and molybdenum have been widely recognized, information regarding their optimum application under the agro-climatic conditions of Haryana remains limited. Crop response to these nutrients varies considerably with soil characteristics, climatic conditions, and crop management practices. Therefore, location-specific nutrient recommendations are essential for improving nutrient use efficiency, sustaining soil fertility, and maximizing crop productivity (Patel et al., 2024; Reddy et al., 2020) [12,13] . With the growing demand for pulses and the increasing emphasis on sustainable crop production, balanced nutrient management has become indispensable for enhancing green gram productivity. Optimizing phosphorus and molybdenum nutrition is expected to improve nodulation, nutrient uptake, growth, yield attributes, seed yield, and economic returns while maintaining long-term soil health (Gupta et al., 1991; Hale et al., 2001) [14,15] . Keeping these facts in view, the present investigation was undertaken to evaluate the effect of different levels of phosphorus and molybdenum on the growth, yield attributes, yield, nutrient uptake, and economics of summer green gram under the agroclimatic conditions of Ambala, Haryana. The findings of the study are expected to generate scientific information for developing location-specific nutrient management strategies to enhance the productivity, profitability, and sustainability of summer green gram cultivation in the region.

Materials and Methods

Experimental Site

The field experiment was conducted during the kharif season of 2025 at the Research Farm (Agronomy Section), Faculty of Agriculture, Maharishi Markandeshwar (Deemed to be University), Mullana-Ambala, Haryana.

Experimental details:

The field experiment was conducted at Research Farm, MMDU, Ambala, in a Split block design comprising twelve treatments (table 1) with three replications with moong variety MH 1142. All the agronomic practices were performed as per mentioned in package and practice of CCSHAU, Hisar.

Main plot (phosphorus)

Sub plot (molybdenum) P1: Control M1: Ammonium molybdate (0gm) P2: 75% RDP M2: Ammonium molybdate (500gm) P3: 100% RDP M3: Ammonium molybdate (1000gm) P4: 125% RDP

Observations recorded

Observations on growth, nodulation, yield attributes, and yield were recorded at different crop growth stages using standard procedures. Plant height (cm) and the number of primary branches were measured from five randomly tagged plants at 25 DAS, 45 DAS, and at harvest. Dry matter accumulation (g) was determined by destructive sampling after oven drying the plant samples to constant weight. At 45 DAS, root nodules from the tagged plants were counted and their dry weight was recorded after oven drying. Yield attributes, including the number of pods per plant, seeds per pod, and 1000-seed weight, were assessed at maturity. Seed yield, stover yield, and biological yield were recorded on a plot basis and converted to kg ha⁻¹. Harvest index (%) was calculated as the ratio of seed yield to biological yield and expressed as a percentage.

Data Analysis

The data collected from experiment undergo Statistical analysis by applying the split plot design for analysis of variance (ANOVA) as suggested by O.P Sheoran (2004).

Results

The data presented in Table 1 indicate that plant height of summer green gram increased progressively with crop age and was significantly influenced by phosphorus and molybdenum application, whereas their interaction remained non-significant at all growth stages. Among the phosphorus treatments, the application of 125% RDP recorded the maximum plant height of 24.30 cm, 44.90 cm, and 61.94 cm at 30 DAS, 45 DAS, and harvest, respectively, which was statistically at par with 100% RDP (24.00, 44.80, and 61.70 cm). The lowest plant height was observed under the control treatment (20.30, 41.30, and 58.23 cm). Similarly, molybdenum application significantly enhanced plant height, with 1.0 kg ha⁻¹ producing the tallest plants (23.90, 44.60, and 61.70 cm), followed closely by 0.5 kg ha⁻¹ (23.30, 44.40, and 60.88 cm), while the untreated control recorded the minimum values (21.00, 42.00, and 58.90 cm). The interaction effect between phosphorus and molybdenum was found to be non-significant throughout the crop growth period.

Total number of branches plant -1

The results presented in Table 2 revealed that the total number of branches per plant increased steadily from 25 DAS to harvest and was significantly affected by phosphorus and molybdenum application, while their interaction was found to be nonsignificant. Among the phosphorus treatments, 100% RDP and 125% RDP recorded the highest number of branches (3.20, 5.20, and 5.80 at 25 DAS, 45 DAS, and harvest, respectively), and both treatments were statistically at par. The lowest number of branches was observed under the control treatment (2.10, 4.20, and 5.10). Application of molybdenum also significantly increased branching, with 1.0 kg ha⁻¹ producing the maximum number of branches (3.20, 5.10, and 5.80), followed by 0.5 kg ha⁻¹ (3.00, 4.90, and 5.70), whereas the untreated control recorded the minimum values (2.30, 4.40, and 5.30). The interaction effect of phosphorus and molybdenum on branch production remained non-significant throughout the crop growth period.

Nodulation parameters

The data presented in Table 4.3 showed that both phosphorus and molybdenum significantly influenced the number and dry weight of root nodules in summer green gram, whereas their interaction effect was non-significant. Among the phosphorus treatments, the application of 125% RDP produced the highest number of nodules (

Yield attributes

The data presented in Table 4 indicated that phosphorus and molybdenum application significantly improved the yield attributes of summer green gram, whereas their interaction effect remained non-significant. [16, 17] . Likewise, molybdenum application at 1.0 kg ha⁻¹ enhanced plant growth by improving nitrogen metabolism, assimilate production, and their efficient translocation within the plant, resulting in greater plant height and branching. Similar findings were also reported by Alam et al. (2020) [1] .

Yield attributes

The improvement in yield attributes, including the number of nodules, nodule dry weight, pods per plant, seeds per pod, and test weight, was primarily associated with the balanced application of phosphorus and molybdenum. [18,19,17] . Similar improvements in seed formation under adequate phosphorus nutrition were also reported by Kumar and Debbarma (2023) [20] . Application of molybdenum at 1.0 kg ha⁻¹ further promoted nodulation, nitrogen metabolism, and nutrient utilization, leading to superior yield-contributing characters. These findings are in agreement with those of Jena et al. (2022) [21] , while the increase in test weight may be attributed to improved photosynthate translocation as reported by Singh et al. (2018) [22] and Vaishnavi et al. (2023) [23] .

Yield

The significant improvement in seed yield, stover yield, biological yield, and harvest index with phosphorus and molybdenum application can be attributed to enhanced nutrient availability, efficient photosynthesis, and improved assimilate production and translocation. Adequate phosphorus promoted root development, nitrogen fixation, energy transfer, and reproductive growth, thereby increasing biomass accumulation and seed production (Hangsing et al., 2019; Maish et al., 2020) [18, 19] . Improved source-to-sink translocation under optimum phosphorus nutrition also contributed to higher yields, as reported by Kumar and Debbarma (2023) [20] and Rathod et al. (2023) [24] . Similarly, application of molybdenum at 1.0 kg ha⁻¹ enhanced nitrogen metabolism and nutrient utilization, resulting in greater biomass production and yield. These findings are consistent with the observations of Jena et al. (2022) [21] , who reported improved pulse productivity under adequate molybdenum nutrition.

Conclusion

In conclusion, it can be demonstrated that the application of phosphorus and molybdenum significantly improved the growth, nodulation, yield attributes, and yield of summer green gram Although 125% RDP produced the higher values for most parameters, it remained statistically at par with 100% RDP.

Application of molybdenum at 1.0 kg ha⁻¹ consistently enhanced crop performance. Therefore, 100% recommended phosphorus dose combined with 1.0 kg molybdenum ha⁻¹ may be considered an efficient and economically viable nutrient management practice for maximizing summer green gram productivity.

References

1. Alam I, Paul AK, Sultana S, Bithy PK. Effect of zinc and molybdenum on the growth and yield of garden pea (Pisum sativum L.). Int J Bio-resource Stress Manag. 2020;11(4):425-431.
2. Arsalan M, Ahmed S, Chaudhary JN, Sarwar M. Effect of vermicompost and phosphorus on crop growth and nutrient uptake in mung bean. J Appl Agric Biotechnol. 2016;1(2):3847.
3. Banerjee P, Nath R. Prospects of molybdenum fertilization in grain legumes: A review. J Plant Nutr. 2022;45(9):14251440.
4. Hou D, Yousaf L, Xue Y, Hu J, Wu J, Hu X, et al. Mung bean (Vigna radiata L.): Bioactive polyphenols, polysaccharides, peptides, and health benefits. Nutrients. 2019;11(6):1238.
5. Movalia JA, Parmar KB, Vekaria LC. Effect of boron and molybdenum on yield and yield attributes of summer green gram (Vigna radiata L.) under medium black calcareous soils. Int J Chem Stud. 2018;6(1):321-323.
6. Patel HR, Patel HF, Maheriya VD, Dodia IN. Response of kharif green gram (Vigna radiata L. Wilczek) to sulphur and phosphorus fertilization with and without biofertilizer application. Bioscan. 2013;8(1):149-152.
7. Theodorou ME, Plaxton WC. Metabolic adaptations of plant respiration to nutritional phosphate deprivation. Plant Physiol. 1993;101(2):339-344.
8. Mendel RR, Hansch R. Molybdoenzymes and molybdenum cofactor in plants. J Exp Bot. 2002;53(375):1689-1698.
9. Westermann DT. Nutritional requirements of potatoes. Am J Potato Res. 2005;82(4):301-307.
10. Rao LK, Singh K. Effect of phosphorus and biofertilizers on leghaemoglobin and nitrogen fixation of chickpea. Madras Agric J. 1983;70(9):572-577.
11. Sun X, Hu C, Tan Q, Liu J, Liu H. Effects of molybdenum on expression of cold-responsive genes in abscisic acid (ABA)-dependent and ABA-independent pathways in winter wheat under low-temperature stress. Ann Bot. 2009;104(2):345-356.
12. Patel DA, Malav JK, Jat JR. Synergistic effects of phosphorus, molybdenum, and Rhizobium on greengram (Vigna radiata L.) yield in light textured soil. Int J Plant Soil Sci. 2024;36(12):496-506.
13. Reddy VRP, Aski MS, Mishra GP, Dikshit HK, Singh A, Pandey R, et al. Genetic variation for root architectural traits in response to phosphorus deficiency in mungbean at the seedling stage. PLoS One. 2020;15(6):e0221008.
14. Gupta G, Grund B, Narayanan R. Photosynthesis and nitrogenase activity in soybean treated with sulphur dioxide and molybdenum. Plant Sci. 1991;79(2):157-161.
15. Hale KL, McGrath SP, Lombi E, Stack SM, Terry N, Pickering IJ, et al. Molybdenum sequestration in Brassica species: A role for anthocyanins? Plant Physiol. 2001;126(4):1391-1402.
16. Kumar S, Yadav SS. Effect of phosphorus fertilization and bio-organics on growth, yield and nutrient content of mungbean (Vigna radiata L. Wilczek). Res J Agric Sci. 2018;9(6):1252-1257.
17. Sahu S, Shankar T, Maitra S, Adhikary R, Mondal T, Duvvada SK. Impact of phosphorus and sulphur on the growth and productivity of green gram (Vigna radiata). Res Crops. 2021;22(4):785-791.
18. Hangsing N, Tzudir L, Singh AP. Effect of spacing and levels of phosphorus on the growth and yield of green gram (Vigna radiata) under rainfed condition of Nagaland. Agric Sci Dig. 2020;40(2):1-5.
19. Maish A, Dawson J, Singh RE. Effect of levels of phosphorus and zinc on growth and yield of greengram (Vigna radiata L.). Int J Curr Microbiol Appl Sci. 2020;9(10):3106-3112.
20. Kumar S, Debbarma V. Effects of phosphorus and boron on growth, yield and economics of green gram (Vigna radiata L.). Int J Plant Soil Sci. 2023;35(11):1-8.
21. Jena B, Nayak RK, Bhol RK, Sahoo S. Soil and foliar application of molybdenum on yield and biochemical quality of green gram (Vigna radiata L.) grown in Fe-rich soils. Bangladesh J Bot. 2022;51(4):689-696.
22. Singh R, Singh V, Singh P, Yadav RA. Effect of phosphorus and PSB on yield attributes, quality and economics of summer green gram (Vigna radiata L.). J Pharmacogn Phytochem. 2018;7(2):404-408.
23. Vaishnavi N, Debbarma V, Kavya L. The effect of phosphorus and molybdenum on growth and yield of cowpea (Vigna unguiculata L.). Int J Environ Clim Change. 2023;13(6):14-22.
24. Rathod AD, Modhvadia JM, Patel RJ, Thanki RB, Bhedarada ND. Enhancing yield, quality, and nutrient content of green gram (Vigna radiata L.) through phosphorus fertilization and thiourea application. Pharma Innovation J. 2023;12(12):3651-3654.