Effect of different levels of potassium and molybdenum on yield attributes and economics of maize (Zea mays L.)

Introduction

Maize provides food, feed, fodder and serves as a source of basic raw material for a number of industrial products viz, starch, protein, oil, alcoholic beverages, food sweeteners, cosmetics, bio-fuel, etc. Maize is the third most important food grain in India after wheat and rice and it is cultivated over approximately 11-12 million hectares area with an annual production of 43.41 million Metric tonnes during 2024-25 and an average productivity of 3.5 t/ha to 4.0 t/ha (Maize in 2025 as per APEDA data). It was introduced in India during the 16th century by the Portuguese. The United States is the largest producer of maize oil. Brazil, China, Romania, countries of the former Soviet Union, former Yugoslavia and South Africa also produce maize oil (Erenstein et al. 2022) [3] . It is a co-product of wet and dry milling industries, which essentially breaks down maize into starch, oil, protein and some of the important vitamins and minerals (Gupta et al. 2016) [5] . Maize oil contains a high proportion of unsaturated fatty acids, of which nearly 78-82% is linoleic acid, an essential fatty acid important for human nutrition. Linoleic acid plays a significant role in lowering harmful cholesterol levels, maintaining elasticity of blood vessels, improving cardiovascular health, and reducing the risk of atherosclerosis (Sharma and Verma, 2021) [18,21] . Apart from linoleic acid, maize oil is also enriched with beneficial compounds such as phytosterols, vitamin E, tocopherols, and other bioactive nutrients that contribute to better human health. Maize oil possesses approximately 2.2 times higher calorific value per unit weight compared to starch, thereby increasing the overall energy value of maize grains. The majority of oil is concentrated in the germ portion of the kernel. In normal maize, the germ contains around 28-32% oil, whereas in high-oil maize genotypes the oil concentration may reach up to 48-52% (Kumar et al. 2020) [7] . High-oil maize lines are also reported to possess improved protein quality with relatively higher lysine content and greater concentration of yellow pigments such as carotenoids and xanthophylls, which are important for poultry feed and human nutrition. In addition, high-oil maize contains elevated levels of vitamin E (tocopherol), a natural antioxidant that protects fatty acids from oxidative damage and enhances the storage stability and shelf life of maize oil (Patel and Singh, 2022) [12,19] . In recent years, greateremphasis has been placed on the exploitation of heterosis for quality traits such as oil and starch content. www.extensionjournal.com During 2022-2024, several private seed companies in India initiated breeding programmes focusing on specialty maize hybrids including high-oil and quality protein maize hybrids. Recent studies comparing oil accumulation patterns in high-oil and normal maize inbred lines revealed that highoil genotypes accumulate oil more rapidly during 18-45 days after pollination, resulting in significantly higher final oil content in the kernels (Reddy et al. 2024) [14] . In the Indian context, maize occupies an important position among cereal crops and ranks third after rice and wheat in terms of area and production (Kalyanasundaram and Augustine, 2021) [6] . It is cultivated in diverse agro-ecological regions ranging from the Himalayan foothills to the tropical plains. The crop is grown during different seasons, namely Kharif, Rabi, and Zaid, depending upon regional climatic conditions (Adhikary et al. 2020) [1] . Potassium has also been referred to as the 'quality nutrient'. The quality effects are more closely linked to its interactions with nutrients such as nitrogen, than to absolute levels of K. Increasing the dose of K increases the K uptake by plants due to increase in interaction of K ions and roots of plants with increasing K availability in soil. Potassium levels increase the shoot contents of N, P, K, Ca, S and Zn in the plants due to its stimulation of root and shoot growth (Filho et al., 2017) [4] . Well-developed root systems have the ability to exploit a greater soil volume, which is fundamental principle for increasing the contact between roots and nutrients, resulting in an improvement in nutrient uptake (Kumar et al. 2024) [8] . Molybdenum (Mo) is a trace element found in the soil and is required for optimum growth of plants. Despite its low availability, Mo ranks 53rd in the earth's crust. Compared to many other micronutrients, Potassium is more readily available for biological processes because other metals are often present in chemical forms that are difficult for plants to assimilate (Xiong et al. 2017) [22] . Recent investigations demonstrated that Potassium supplementation improved chlorophyll content, root development, photosynthetic efficiency, and biomass accumulation in crops exposed to drought and cadmium stress (Zahedi et al. 2024) [24] .

Materials and method

This experiment was carried out during kharif 2025 at Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj, (U.P), which is located at 25.28o N latitude, 81.54oE longitude and 98 m altitude above the mean sea level. This area situated on the right side of the Yamuna River by the side of Allahabad Rewa Road about 5 km away from Prayagraj city. All the facilities required for crop cultivation were met out from the department. to check the Effect of Different Levels of Potassium and Molybdenum on growth and yield of Maize The plot size of each treatment was 3m x 3m. The experiment was laid out in randomised block design consisting of ten treatment. The factors are Potassium (40 kg/ha, 50 kg/ha, 60 kg/ha) and Molybdenum (30 g/ha, 40 g/ha, 50 g/ha). The treatments combination are (T1., Potassium 40 kg/ha + Molybdenum 30 g/ha), (T2 Potassium 40 kg/ha + Molybdenum 40 g/ha), (T3 Potassium 40 kg/ha + Molybdenum 50 g/ha), (T4 Potassium 50 kg/ha + Molybdenum 30 g/ha), (T5 Potassium 50 kg/ha + Molybdenum 40 g/ha), (T6 Potassium 50 kg/ha + Molybdenum 50 g/ha), (T7 Potassium 60 kg/ha + Molybdenum 30 g/ha), (T8 Potassium 60 kg/ha + Molybdenum 40 g/ha), (T9 Potassium 60 kg/ha + Molybdenum 50 g/ha),(T10 120 -60 -40 kg/ha N-P-K ( Control)). Maize Seeds were sown in line manually. Seeds were covered with soil immediately after sowing. The Maize crop was sown on 11th August 2025. Harvesting was done by taking 1 m2 area from each. And randomly selected area in 1m2 yield attributes and economics parameters. The observations recorded for post-harvest data Number of cobs/plants, Number of grains/rows, Number of row/cobs, cob length (cm), cob yield (t/ha), grain yield (t/ha), stover yield (t/ha) harvest index. The data was subjected to statistical analysis by Analysis of variance method. Economics was calculated viz., cost of cultivation, gross return, net return, benefit cost ratio were calculated.

Result and discussion

Yield Parameters Number of cobs per plant

At harvest significantly higher number of cobs per plant (3.2) was recorded with the application of Potassium 60 kg/ha +Molybdenum 50 g/ha and minimum was reported in Control (RDF) -NPK -120-60-40 kg/ha) (1.2). However, Potassium 60 kg/ha + Molybdenum 40 g/ha (3.0) was statistically at par with Treatment 9. The significant increase in the number of cobs per plant with potassium application at 60 kg/ha may be attributed to enhanced photosynthesis, enzyme activation and efficient translocation of assimilates to reproductive organs, leading to improved cob formation and reproductive growth in maize. Similar results were reported by Yadav et al. (2021) [23] . The higher number of cobs per plant with molybdenum application at 50 g/ha might be due to improved nitrogen utilization, enzyme activity and protein synthesis. Enhanced chlorophyll content and photosynthetic efficiency increased assimilate supply to developing cobs, resulting in better cob setting. Similar findings were reported by Kumar et al. (2020) [7] .

Number of row/cob

At harvest significantly higher Maximum number of row/cob (16.0) was recorded with the application of Potassium 60 kg/ha + Molybdenum 50 g/ha and minimum was reported in Control (RDF) -NPK -120-60-40 kg/ha) (10.46). However, Potassium 60 kg/ha + Molybdenum 30 g/ha (14.8), Potassium 60 kg/ha + Molybdenum 40 g/ha (15.0) was statistically at par with Treatment 9. The significant increase in the number of rows per cob with potassium at 60 kg/ha may be attributed to enhanced photosynthetic activity, efficient carbohydrate translocation and improved reproductive growth, resulting in better cob development and grain setting. Similar findings were reported by Patel et al. (2019) [11] . The increased number of rows per cob with molybdenum at 50 g/ha might be due to improved nitrogen metabolism, protein synthesis and photosynthetic efficiency, which promoted superior cob development and reproductive performance. Similar observations were reported by Singh et al. (2021) [19] .

Number of grains/row

At harvest significantly higher Maximum number of www.extensionjournal.com grains/row (42.73) was recorded with the application of Potassium 60 kg/ha + Molybdenum 50 g/ha and minimum was reported in Control (RDF) -NPK -120-60-40 kg/ha) (28.66). However, Potassium 60 kg/ha + Molybdenum 40 g/ha (39.0) was statistically at par with Treatment 9. The significant increase in the number of grains per row with potassium application at 60 kg/ha might be attributed to enhanced photosynthetic efficiency, better translocation of carbohydrates and improved grain setting, which ensured a continuous supply of assimilates to developing grains. Similar findings were reported by Verma et al. (2020) [21] . The increase in the number of grains per row with molybdenum application at 50 g/ha might be due to improved nitrogen metabolism, enzyme activity and nutrient utilization, leading to better grain formation and development in maize. Similar observations were reported by Sharma et al. (2022) [17] .

Test weight

At harvest the significantly higher maximum Test weight (20.35 g) was observed in (treatment 9) Potassium 60 kg/ha + Molybdenum 50 g/ha compared to the control (18.09 g). Whereas Potassium 60 kg/ha + Molybdenum 30 g/ha (19.76 g), Potassium 60 kg/ha + Molybdenum 40 g/ha (19.93 g). Correspondingly found to be statically at par with Treatment 9.The significant increase in test weight with potassium application at 60 kg/ha might be attributed to enhanced photosynthetic activity, efficient translocation of assimilates and improved grain filling, resulting in heavier and welldeveloped grains. Similarly, molybdenum application at 50 g/ha might have increased test weight through improved nitrogen metabolism, protein synthesis and chlorophyll formation, which enhanced grain development and dry matter accumulation. These observations corroborate the findings of Pandey et al. (2020) [10] .

Cob length

At harvest the significantly higher cob length (18.61) was recorded with the application of Potassium 60 kg/ha + Molybdenum 50 g/ha and minimum was reported in Control (RDF) -NPK-120-60-40 kg/ha) (11.15). However, Potassium 50 kg/ha + Molybdenum 50 g/ha (17.46), Potassium 60 kg/ha + Molybdenum 30 g/ha (17.65), Potassium 60 kg/ha + Molybdenum 40 g/ha (17.93) were statistically at par with Treatment 9. The increased cob length with potassium application at 60 kg/ha might be attributed to enhanced photosynthetic activity, efficient carbohydrate translocation and improved cell elongation, which promoted better cob growth and development. Similar findings were reported by Verma et al. (2020) [21] . Molybdenum application at 50 g/ha might have increased cob length through improved nitrogen metabolism, protein synthesis and enzymatic activity, resulting in better reproductive growth and cob development. Similar observations were reported by Kumar et al. (2020) [7] .

At harvest the significantly higher cob yield (10.36 t/ha) was recorded with the application of Potassium 60 kg/ha + Molybdenum 50 g/ha and minimum was reported in Control (RDF) -NPK -120-60-40 kg/ha) (6.22 t/ha) However, Potassium 60 kg/ha + Molybdenum 40 g/ha (8.65 t/ha) was statistically at par with Treatment 9. Further, the higher cob yield with potassium application at 60 kg/ha might be attributed to enhanced photosynthetic efficiency, improved translocation of assimilates and better cob development. Adequate potassium nutrition ensured efficient utilization of nutrients and greater accumulation of dry matter in cobs, resulting in increased cob yield. Similar findings were reported by Patel et al. (2019) [11] . Similarly, molybdenum application at 50 g/ha might have increased cob yield through improved nitrogen metabolism, enzyme activity and nutrient use efficiency. Enhanced vegetative growth and reproductive development promoted better cob formation and development, leading to higher cob yield in maize. These findings are in agreement with Kumar et al. (2020) [7] .

At harvest the significantly higher grain yield (7.40 t/ha) was recorded with the application of Potassium 60 kg/ha + Molybdenum 50 g/ha and minimum was reported in Control (RDF) -NPK -120-60-40 kg/ha) (3.02 t/ha) However, Potassium 60 kg/ha + Molybdenum 40 g/ha (6.17) was statistically at par with Treatment 9. Further, the higher grain yield with potassium application at 60 kg/ha might be attributed to enhanced photosynthetic efficiency, carbohydrate translocation and improved grain filling. Adequate potassium nutrition ensured better assimilate supply to developing grains, resulting in increased grain yield in maize. Similar findings were reported by Choudhary et al. (2021) [2] . Similarly, molybdenum application at 50 g/ha might have increased grain yield through improved nitrogen metabolism, protein synthesis and nutrient use efficiency. Enhanced photosynthetic activity and reproductive development promoted better grain setting and grain filling, leading to higher grain yield in maize. Similar observations were reported by Meena et al. (2020) [9] .

At harvest the significantly higher stover yield (15.13 t/ha) was recorded with the application of Potassium 60 kg/ha + Molybdenum 50 g/ha and minimum was reported in Control (RDF)-NPK -120 60-40 kg/ha) (8.28 t/ha). However, Potassium 60 kg/ha + Molybdenum 30 g/ha (14.30 t/ha), Potassium 60 kg/ha + Molybdenum 40 g/ha (14.77 t/ha) was statistically at par with Treatment 9. Further, the higher stover yield with potassium application at 60 kg/ha might be attributed to enhanced photosynthetic activity, efficient carbohydrate translocation and improved water-use efficiency. These factors promoted vigorous vegetative growth and greater biomass accumulation, resulting in higher stover yield in maize. Similar findings were reported by Saini et al. (2020) [16] . Similarly, molybdenum application at 50 g/ha might have increased stover yield through improved nitrogen metabolism, protein synthesis and nutrient utilization. Enhanced vegetative growth and dry matter production under adequate molybdenum nutrition contributed to greater biomass accumulation and higher stover yield in maize. Similar observations were reported by Prajapati et al. (2022) [13] . www.extensionjournal.com

Maximum harvest index (35.43%) was recorded with the application of Potassium 60 kg/ha + Molybdenum 50 g/ha, minimum was reported in Control (RDF) -NPK -12-60-40 kg/ha) (22.50%) and there was no significant change in between the treatments.

Economics

Gross returns, Net returns and Benefit cost ratio were significantly influenced due to different treatments.

Cost of cultivation (INR 80,650.00 /ha) was found to be higher in the treatment 9 [Potassium 60 kg/ha + Molybdenum 50 g/ha].

Gross return (INR 2, 53,250.00 /ha) was found to be higher in the treatment 9 [Potassium 60 kg/ha + Molybdenum 50 g/ha].

Net return (INR 1, 72,600.00 /ha) was found to be higher in the treatment 9 [Potassium 60 kg/ha + Molybdenum 50 g/ha] Benefit cost ratio (B: C) Benefit cost ratio (2.14) was found to be higher in the treatment 9 [Potassium 60 kg/ha + Molybdenum 50 g/ha]. Maximum benefit cost ratio was recorded with plant geometry 45 cm x 15 cm observed maximum benefit cost ratio, this could be due to it allows adequate plant stand with sufficient aeration and sunlight interception, promoting higher tillering which improve the yield without proportionally increasing the cost of cultivation, thereby resulting in higher economics return.

Acknowledgement

AcknowledgementMy dearest advisor Prof. (Dr). Vikram Singh, and all faculty members from the Department of Agronomy, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Science Prayagraj, (U.P) India, contributed to the work by allotting field and assisting with the research trail.

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