Effect of zn and fe biofortification on growth, yield and economics of sorghum (Sorghum Bicolor L.)

Introduction

Sorghum (Sorghum bicolor L.), a member of the family Poaceae, is one of the most versatile and resilient cereal crops cultivated across the semi-arid and arid tracts of the world. Sorghum is also known as the "king of millets" and the "camel crop" on account of its drought tolerance. World sorghum output was placed at about 52.8 million tonnes during 2024-25, with the United States (14%), Nigeria (11%), Brazil (8%) and India (8%) together accounting for more than 40% of global production (CARP, 2024). In India, sorghum is cultivated on about 4.6 million hectares with a production of 4.8 million tonnes at a productivity of 1.1 tonnes/hectare (DES, MoA&FW, 2023), although India remains among the leading sorghum-growing countries, the area under the crop has been shrinking steadily over the past six decades in favour of more remunerative crops, even as productivity has improved through varietal and management interventions (Choi andEltahir, 2023 andCARP, 2024). Micronutrient malnutrition, often described as 'hidden hunger', remains one of the most pervasive yet under-addressed public health challenges of the present century. The World Health Organization has long recognised inadequate levels of Zn, Fe and vitamin A among the populations of developing countries as a major public health and socio-economic problem (WHO 2002 andWelch 2002), with Zn deficiency cited as the fifth leading cause of morbidity and mortality in these nations (WHO, 2002) and approximately 2.7 billion people estimated to be Zn deficient worldwide (Muller and Krawinkel, 2005). Because a substantial share of anaemia in women and children continues to be attributed to inadequate dietary Fe even after decades of supplementation and fortification programmes, cereal-based agronomic interventions capable of simultaneously raising both grain Zn and Fe density have assumed considerable importance in national nutrition strategies (Ullah et al., 2024). In the plant system, Zn functions as a structural or catalytic cofactor for more than three hundred enzymes and proteins involved in carbohydrate metabolism, protein synthesis, membrane integrity and the biosynthesis of the growth hormone auxin, and is therefore indispensable for cell division, internode elongation and reproductive development (Alloway, 2008). Fe is necessary to carry out metabolic processes like DNA synthesis, respiration, photosynthesis, nitrate and sulphate reduction, and to maintain the structure and functionality of chloroplasts because it acts as an electron carrier in the electron transport chain (Rout and Sahoo, 2015). Biofortification is a novel and sustainable agricultural strategy that seeks to enhance the Zn and Fe content in crops to tackle these deficiency problem through genetic, agronomic and conventional breeding approaches. Among these, agronomic bio fortification is comparatively rapid and low-cost method for increasing Zn and Fe content within one season through soil and foliar application.

Materials and Methods

A field experiment entitled "Effect of Zn and Fe Biofortification on Growth, Yield and Economics of Sorghum (Sorghum bicolor L.)" was conducted in 2025 during the Kharif season at crop research centre of the Sardar Vallabhbhai Patel University of Agriculture and Technology in Meerut (U.P.). The experimental site is located at a latitude of 29° 40' North and a longitude of 77° 42' East, at an altitude of 237 metres above mean sea level with a subtropical climate, Meerut lies in the central part of western Uttar Pradesh. The soil of the experimental field was sandy loam in texture, low in organic carbon (0.40 %) and available nitrogen (218.5 kg/ha), medium in available phosphorus (13.70 kg/ha), available potassium (238.8 kg/ha), Zn (0.64 ppm) and Fe (7.7 ppm), exhibited a near-neutral reaction. CSV-15 is a dual-purpose sorghum variety was sown on 22 august 2025. The experiment was laid out in a Randomized Block Design (RBD) comprising 10 treatments with 3 replications. Therefore, in each replication, there were 10 plots of gross plot size (5m x 4.5m) and net plot size (4.4m x 3.6m). The treatment comprised, T1: Absolute control, T2: 100% RDF (90:45:45 kg NPK ha-1), T3: RDF + ZnSO 4 25 kg ha -1 soil application, T4: RDF + FeSO 4 25 kg ha -1 soil application, T5: RDF + 0.5% ZnSO 4 foliar spray at 25 and 45 DAS, T6: RDF + 0.5% FeSO 4 foliar spray at 25 and 45 DAS, T7: RDF + 0.5% ZnSO 4 and 0.5% FeSO 4 foliar spray at 25 and 45 DAS, T8: 75% RDF + foliar spray of liquid NPK (0.3%) + 0.5% ZnSO 4 foliar spray at 25 and 45 DAS, T9: 75% RDF + foliar spray of liquid NPK (0.3%) + 0.5% FeSO 4 foliar spray at 25 and 45 DAS, and T10: 75% RDF + foliar spray of liquid NPK (0.3%) + foliar spray of 0.5% ZnSO 4 and 0.5% FeSO 4 at 25 and 45 DAS.

Results and discussion 1. Yield attributing characters

The data on yield attributing characters, viz., number of earhead m -2 , length of earhead, number of grains per earhead and test weight as influenced by Zn and Fe biofortification are presented in Table 1. 2. Yield (q ha -1 )

The grain yield was influenced by Zn and Fe biofortification at different time of crop growth. Treatment T 10 (75% RDF + foliar spray of liquid NPK (0.3%) + foliar spray of 0.5% ZnSO 4 and 0.5% FeSO 4 ) recorded maximum grain yield (38.93 q ha -1 ) which remained statistically at par with treatment T 7 (RDF + 0.5% ZnSO 4 and 0.5% FeSO 4 foliar spray at 25 and 45 DAS) which recorded (37.45 q ha -1 ), but significantly higher than all other treatments. The mean increased in grain yield was 97.01% and 89.5% in T 10 (75% RDF + foliar spray of liquid NPK (0.3%) + foliar spray of 0.5% ZnSO 4 and 0.5% FeSO 4) and T 7 (RDF + 0.5% ZnSO 4 and 0.5% FeSO 4 foliar spray at 25 and 45 DAS) respectively over control treatment. The lowest grain yield was recorded in absolute control (T 1 ) is (19.76 q ha -1 ).

The stover yield was influenced by Zn and Fe biofortification at different time of crop growth. Treatment T 10 (75% RDF + foliar spray of liquid NPK (0.3%) + foliar spray of 0.5% ZnSO 4 and 0.5% FeSO 4 ) recorded maximum stover yield (125.1 q ha -1 ) which remained statistically at par with treatment T 7 (RDF + 0.5% ZnSO 4 and 0.5% FeSO 4 foliar spray at 25 and 45 DAS) which recorded (121.9 q ha -1 ), but significantly higher than all other treatments. The mean increased in stover yield was 66.1% and 61.8% in T 10 (75% RDF + foliar spray of liquid NPK (0.3%) + foliar spray of 0.5% ZnSO 4 and 0.5% FeSO 4) and T 7 (RDF + 0.5% ZnSO 4 and 0.5% FeSO 4 foliar spray at 25 and 45 DAS) respectively over control treatment. The lowest stover yield was recorded in absolute control (T 1 ) is (75.3 q ha -1 ). The same results were in agreement with those reported by Yankam et al. (2024) and Kubsad (2019).

Zn and Fe content and uptake 3.1 Zn content and uptake

The data on Zn content in grain and straw, and Zn uptake by grain, straw and total uptake as influenced by Zn and Fe biofortification are presented in Table 3.1.

Fe content and uptake

The data on Fe content in grain and straw, and Fe uptake by grain, straw and total uptake as influenced by Zn and Fe biofortification are presented in Table 3.2. Fe content in grain and straw was significantly influenced by various treatments imposed. The maximum Fe content in grain (76.12 ppm) and straw (132.54 ppm) and Fe uptake in grain (296.3 g ha -1 ) and straw (1658.1 g ha -1 ) was recorded under T 10 (75% RDF + foliar spray of liquid NPK (0.3%) + foliar spray of 0.5% ZnSO 4 and 0.5% FeSO 4 ), which remained statistically at par with T 7 (RDF + 0.5% ZnSO 4 and 0.5% FeSO 4 foliar spray at 25 and 45 DAS) which recorded Fe content in grain (73.97 ppm) and straw (128.76 ppm) and Fe uptake in grain (277.0 g ha -1 ) and straw (1569.6 g ha -1 ). The same results were in agreement with those reported by Habib (2009).

Conclusion

On the basis of the results obtained during the present investigation, it may be concluded that combined foliar application of 0.5% ZnSO 4 and 0.5% FeSO 4 at 25 and 45 DAS along with 75% RDF supplemented with foliar spray of liquid NPK (0.3%) treatment T 10 was the most effective and remunerative treatment for realising yield attributes, yield, and Zn and Fe content and uptake in sorghum. Treatment T 7 (100% RDF + combined foliar spray of 0.5% ZnSO 4 and 0.5% FeSO 4 at 25 and 45 DAS) was the next best treatment means statistically at par with T 10 and may be recommended where farmers are unwilling to reduce the level of major fertilizer application.

Acknowledgement

The authors express sincere gratitude to the Hon'ble Vice Chancellor and Director of Research, Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, India (250110), for providing necessary facilities to carry out this study. The authors are also thankful to the Head (my chairperson), Department of Agronomy, and advisory committee for their guidance and support throughout the research work. Sincere thanks are extended to the faculty members and technical staff to the Crop Research Centre for their assistance during field experiment.

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