Millets, recognized as important nutri-cereals, are cultivated extensively across both local and global scales (Yin et al., 2023). They are particularly rich in key micronutrients such as calcium, magnesium, potassium and iron. Remarkably, the calcium content in millets is nearly ten times higher, while the iron concentration is two to ten times greater than that of wheat and rice (Ananthi and Parasuraman, 2020). Foxtail millet, a predominantly self-pollinated species belonging to the Poaceae family, has been cultivated for millennia. It continues to serve as a critical dietary staple for millions of people living in arid and semi-arid regions, highlighting its enduring significance in global agriculture (Sivakumar et al., 2022).
       
In India, small millets occupy around 4.59 lakh hectares, yielding approximately 3.3 lakh tons with an average productivity of 809 kg/ha. However, productivity is often constrained by nutrient and moisture stresses (Louhar et al., 2020). Soil fertility, in particular, remains a major limiting factor for crop growth. The potential yield of foxtail millet in India is frequently decreased due to limited fertilizer application, reliance on traditional low-yielding cultivars and inappropriate management practices. Moreover, the adoption of high-yielding varieties in several crops has intensified the use of chemical fertilizers devoid of micronutrients (Murugesan et al., 2024). At the same time, the scarcity of organic manures has further aggravated nutrient imbalances and micronutrient deficiencies, ultimately lowering yields. Thus, ensuring balanced and adequate supply of both macro and micronutrients is essential for improving crop productivity.

Although required in small amounts, micronutrients play indispensable roles in regulating plant growth and development. Among modern techniques, foliar application of micronutrients in liquid form directly to leaves has gained attention. Studies indicate that foliar application can be equally or more effective than soil-based application (Manjunath and Debbarma, 2023). Iron (Fe) is vital for chlorophyll biosynthesis as well as enzymatic and metabolic processes critical to plant survival. Zinc (Zn) supports photosynthesis, nitrogen assimilation, auxin regulation, enzyme activation and ion transport (Wang et al., 2023). Boron (B), another essential element, contributes to cell wall integrity, cell division, reproductive development, sugar transport and hormonal regulation.

The SRM College of Agricultural Sciences in Chengalpattu, Tamil Nadu, India, hosted the field experiment during the summer (Febraury - April), 2024 under irrigated conditions. The experimental site is located at 12.389^oN latitude, 79.742^oE longitude and an elevation of 66 meters above mean sea level (MSL) in Tamil Nadu. Before the experiment commenced, a soil sample was collected from the top 15 centimeters of the site. The soil was clayey in texture, with a neutral pH of 7.39, low organic matter content (0.39%) and low levels of available N (100.4 kg/ha) and P₂O₅ (10 kg/ha), but a medium level of available K₂O (160 kg/ha). Weather conditions during the growing season are provided in Fig 1. The experiment was designed as a split-plot, with three main plots and four sub-plots, each replicated three times. The main plots includes M₁: 100% RDF (40:20:0 kg/ha), M₂: 50% RDF and M₃: 12.5 t/ha FYM and Subplot consists of S₁: Soil application of TNAU MN mixture at 12.5 kg/ha, S₂: Foliar spray of 0.5% FeSO₄ + 0.5% ZnSO₄ + 0.2% Borax, S₃: Foliar spray of 3% Panchagavya and S₄: Foliar spray of 3% Jeevamrutham.  The ATL 1 variety foxtail millet seeds was placed 20 × 10 cm apart. Foliar application given at 30 DAS (at active tillering) and 45 DAS (at flowering). At harvest, five randomly selected plants were placed in the net plot area for observations.


       
Plant height was recorded at harvest by measuring the distance from the base of the stem to the tip of the panicle for five randomly selected plants from each treatment. The number of tillers per hill was observed for the same five plants from each plot and the mean values were calculated. Total dry matter production was also recorded at harvest, where five plants per replication were randomly selected, uprooted, cleaned, sun-dried and then oven-dried at 80^oC until reaching a constant weight, expressed as grams per hill.
       
The number of panicles per hill was determined by counting panicles from five tagged plants and calculating the mean, while grains per panicle were obtained by counting ten panicles and mean was calculated. Panicle length and weight were measured from five randomly selected foxtail millet plants, with length recorded from scar to tip (cm) and weight in grams. Thousand-grain weight was determined by weighing 1000 number of grains sampled from panicles. At full maturity, the crop was harvested, sun-dried, threshed, winnowed and cleaned to record grain yield (kg/ha), while straw yield was separately harvested, dried and expressed in kg/ha. The harvest index was calculated as a percentage using the formula suggested by Donald (1962).

Growth parameters
 
Among the treatment combination, 100% RDF and 0.5% ferrous sulphate + 0.5% zinc sulphate + 0.2% borax at 30 DAS and 45 DAS (M₁S₂) produced the tallest plant at harvest (Table 1). Plant height showed a 17% increase in treatments receiving 100% RDF combined with foliar application of 0.5% ferrous sulphate + 0.5% zinc sulphate + 0.2% borax, compared to plants supplied with lower NP and 3% jeevamrutham at 30 and 45 DAS. This improvement can be attributed to the foliar supply of micronutrients during the tillering and flowering stages, in conjunction with NPK fertilizers, which collectively enhanced plant height. The increase was mainly due to higher photosynthetic efficiency, improved chlorophyll synthesis and the synergistic role of boron in facilitating nitrogen uptake, all of which contributed to vigorous vegetative growth. Similar result was found by John et al., (2022) and Manjunath and Debbarma (2023).


 
Number of tillers per plant
 
Soil application of 100% RDF along with foliar spray of 0.5% ferrous sulphate + 0.5% zinc sulphate + 0.2% borax at 30 DAS and 45 DAS recorded the higher number of tillers at harvest (Table 1). This improvement may be ascribed to the integrated supply of nutrients through both soil and foliar application. The effect is closely associated with the role of iron as a structural component, essential for photosynthesis and respiration. Elevated levels of NPK, Fe, Zn and B promote the growth and differentiation of axillary buds, leading to increased tiller production. Furthermore, the rapid conversion of assimilated carbohydrates into proteins, along with the enhancement in both number and size of growing cells, contributes to a higher total tiller count per plant. The similar results were reported by Umamaheswari et al., (2021) and Yang et al., (2023).
 
Dry matter production
 
Among the interaction effect, soil application of 100% RDF along with foliar spray of 0.5% ferrous sulphate + 0.5% zinc sulphate + 0.2% borax at 30 DAS and 45 DAS produced the higher DMP at harvest (Fig 2). In foxtail millet, 29 per cent increase in DMP was observed in the plants applied 100 % RDF along with foliar spray of 0.5% ferrous sulphate + 0.5% zinc sulphate + 0.2% borax with compared to plants applied with 50% RDF along with foliar spray of Jeevamrutham.   

                    

The combined application of nitrogen and phosphorus along with micronutrients appears to have enhanced crop growth by stimulating dry matter production (DMP). These nutrients influence cellular metabolism, thereby supporting the activity of meristematic tissues and improving nutrient absorption, which ultimately results in greater biomass accumulation (Dass et al., 2022). The observed increase in dry matter production may also be associated with the steady and adequate supply of micronutrients throughout the crop growth period, ensured through foliar application (Zayed et al., 2023).
 
Yield attributes
 
Number of panicles per hill
 
The numbers of panicles per hill were shown in Table 2. The panicle number per plant was greatly increased by the application of NPK and micronutrients in foxtail millet. Application of 100% RDF (M₁) recorded the highest value of panicle number (3.65), outperforming M₃ and M₂. Among the subplots, foliar spraying of ferrous sulphate (0.5%) + zinc sulphate (0.5%) + borax (0.2%) registered the highest number of panicle (3.28), which was comparable to S₁ and S₃. In the interaction effect, M₁S₂ registered the higher panicle number (4.03), which was on par with M₁S₁ (3.80). The increase in the number of productive tillers can be ascribed to enhanced dry matter production (DMP) and its effective translocation to grains under adequate nitrogen availability, which in turn improved overall yield attributes. Similar observations in foxtail millet were documented by Sahoo et al., (2020). In barnyard millet, Vasundhara and Chhabra (2021) also reported a higher number of productive tillers and improved grain filling, which were attributed to efficient uptake and translocation of macro- and micronutrients applied through foliage at critical growth stages. Comparable results were observed by Abdoli (2020) in barnyard millet.


 
Number of grains per panicle
 
The combination of both organic and inorganic sources of micro and macro nutrients significantly enhanced the grain numbers in foxtail millet (Table 2). The highest number of grains per panicle (2436) was observed in treatment M₁ (100% RDF), which was significantly different from other treatments. The interaction effect revealed that M₁S₂ (2527) had the highest grains per panicle, comparable to M₁S₁ (2452) and M₁S₃ (2386) in foxtail millet. Boron is a vital micronutrient involved in cell differentiation, pollen grain formation and plant growth. It also facilitates the translocation of photosynthates, thereby enhancing pollination, seed set and overall metabolic activity in plants. Similar results were reported by Kohli et al., (2023).
 
Panicle length and panicle weight
 
The application of various nutrient sources to the soil and foliar treatments with both micro and macro nutrients registered significant difference in panicle length and weight. The data on panicle length are presented in Fig 3 and panicle weight is presented in Table 3. The interaction effect showed that M₁S₂ had the highest panicle length (22.93 cm), comparable to M₁S₁ (21.65 cm) and M₁S₃ (20.65 cm), while the shortest panicle length in foxtail millet was observed in M₂S₄ (16.52 cm). A similar trend was noted for panicle weight as well. The application of nutrients through foliar spraying at the flowering and grain-filling stages appears to have supported improved nutrient balance, thereby enhancing photosynthetic activity during the post-anthesis phase. This improvement subsequently contributed to better yield traits and overall productivity of foxtail millet, aligning with the observations of Guan et al., (2022). For achieving superior yield attributes, micronutrients such as iron, zinc and boron play a crucial role in various enzymatic and physiological processes, including grain development, panicle elongation and weight, dry matter production and chlorophyll synthesis (Karimian et al., 2023).




 
1000-grain weight
 
The 1000-grain weight values showed no significant differences among the treatments in (Table 3). The interaction effect M₁S₂ (2.60 g) exhibited a higher 1000-grain weight, comparable to M₁S₁ (2.57 g) and M₁S₃ (2.53 g), while the lowest 1000-grain weight was observed in M₂S₄ (2.31 g). This effect can be ascribed to the crucial function of NPK nutrients in supporting meristematic activity and various physiological processes. Their beneficial effect on yield attributes is likely a result of improved nutrient availability, which enhances photosynthate production and facilitates its efficient translocation to the sink (Paul et al., 2020).
 
Grain yield
 
The grain yield is presented in Table 4. This indicates of foxtail millet was significantly influenced by different levels of macro nutrients and micronutrients. The treatment M1 (100% RDF) achieved the highest grain yield of 2329 kg/ha, outperforming M₃ (2035 kg/ha) and M₂ (1816 kg/ha). The highest yield in the subplots were registered in the plants applied with spraying of ferrous sulphate (0.5%) + zinc sulphate (0.5%) + borax (0.2%) through foliage. However, Application of 100 % RDF along with foliar application of ferrous sulphate (0.5%) + zinc sulphate (0.5%) + borax (0.2%) at critical stages showed the highest grain yield at 2486 kg/ha, which was comparable to M₁S₁. The observed increase in grain yield is likely attributed to enhanced metabolic activity and the efficient translocation of carbohydrates from source to the sink. In foxtail millet, higher productivity was achieved through effective nutrient uptake and their subsequent mobilization to developing tillers during critical growth phases. Yield improvement showed a positive association with the availability of NPK throughout the crop growth period, aligning with the findings of Shahzadi et al., (2025). Likewise, Swaroop and Debbarma (2023) suggested that improved carbohydrate synthesis and its transport to the grain formation site may explain the yield benefits associated with zinc fertilization.

                  

Furthermore, Sivakumar et al., (2022) reported that zinc application enhances plant nutrition and dry matter accumulation, which in turn contributes to increased biological yield.
 
Straw yield
 
The data on effect of nutrients on straw yield found to be significantly different (Table 4). Application of 100% RDF resulted in the highest straw yield of 4328 kg/ha, outperforming the other treatments. Similarly, foliar feeding of ferrous sulphate (0.5%) + zinc sulphate (0.5%) + borax (0.2%) recorded the highest straw yield of 4341 kg/ha, followed by S₁. Among the interaction effect, application of 100 % RDF along with foliar application of ferrous sulphate (0.5%) + zinc sulphate (0.5%) + borax (0.2%) (M₁S₂) at critical stages showed the highest straw yield of 4571 kg/ha, which was significantly different from M₁S₃ (4189 kg/ha) and comparable to M₁S₁ (4411 kg/ha). The application of zinc appears to have contributed to the regulation of essential physiological processes in plants, especially chlorophyll synthesis, which subsequently enhanced straw yield in foxtail millet. This positive effect is associated with improved growth and developmental functions, as documented by John et al., (2022) and Yin et al., (2023).
                  
Harvest index    
        
The treatment M₁S₂ shown higher HI value of 0.47 and lowest was registered in M₂S₄ (Fig 4). This indicates that the increase in these yield attributing traits would result in higher grain yield through a significant increase in HI. However, increase in HI alone may reduce the biomass investment in leaves and other vegetative structures, loosing total biomass production (Paul et al., 2020).  Therefore, it is appropriate to focus on ways and means to increase the biomass by maintaining higher HI values in foxtail millet (Sivakumar et al., 2022).

This study confirmed that integrated nutrient management plays a pivotal role in enhancing growth, yield attributes and productivity of foxtail millet under irrigated conditions. The treatment combining 100% RDF with foliar application of Fe, Zn and B recorded superior performance in plant height, tiller number, leaf area index, dry matter production and yield traits. Enhanced grain and straw yields were achieved through balanced nutrient supply and improved physiological efficiency. The results underline the importance of integrating macro and micronutrients to overcome yield limitations in millet cultivation. These findings provide a practical approach for sustainable intensification of foxtail millet production. Future studies should validate the effectiveness of nutrient combinations under different soil and climatic conditions while exploring eco-friendly organic supplements for long-term sustainability.

The Department of Agronomy at SRM College of Agricultural Sciences, Baburayanpettai, Chengalpattu, is acknowledged by the authors for providing the resources needed to carry out this experiment successfully.
 
Disclaimers
 
The views and conclusions expressed in this article are solely those of the authors and do not necessarily represent the views of their affiliated institutions. The authors are responsible for the accuracy and completeness of the information provided, but do not accept any liability for any direct or indirect losses resulting from the use of this content.
 
Informed consent
 
All animal procedures for experiments were approved by the Committee of Experimental Animal care and handling techniques were approved by the University of Animal Care Committee.

The authors declare that there are no conflicts of interest regarding the publication of this article. No funding or sponsorship influenced the design of the study, data collection, analysis, decision to publish, or preparation of the manuscript.