Vikram Singh , and Pardeep Kumar, Ph.D Research Scholar
Dr. Akhil Bharti , Dr. Aaina Sharma, Assistant Professor,
Department of Agriculture, MM (DU), Mullana, Ambala, Haryana, India.

Abstract
Maize (Zea mays L.), a vital cereal crop, faces numerous abiotic and biotic stresses that limit productivity. Salicylic acid (SA), a phenolic phytohormone, plays a significant role in regulating plant defense, physiology, and metabolism. This review summarizes the biochemical, physiological, and agronomic roles of SA in maize cultivation, focusing on stress mitigation and yield enhancement under Haryana’s challenging agro-climatic conditions. Evidence suggests that SA application enhances drought and salinity tolerance, improves photosynthetic efficiency, and supports sustainable maize production.

1. Introduction: Maize is an important kharif crop in Haryana, valued for its grain, fodder, and industrial uses. However, irregular monsoons, water scarcity, and soil salinity in districts like Hisar, Sirsa, and Mahendragarh often reduce yields. Biotic stresses such as leaf blight and stem rot further aggravate losses, particularly in nutrient-deficient soils.

Salicylic acid (SA), a naturally occurring signaling compound in plants, enhances resistance to stress while promoting growth. Recent studies have shown that exogenous application of SA can stimulate antioxidant defense, improve nutrient uptake, and stabilize photosynthesis under stress (Khan et al., 2015). Its eco-friendly and low-cost nature makes SA an attractive intervention for sustainable maize production in Haryana.

2. Role of Salicylic Acid in Maize Growth and Physiology
SA regulates diverse physiological and biochemical processes that determine maize performance under both normal and stressful environments.

2.1 Agronomic Role
  • Seed Germination and Establishment: SA treatment enhances germination rate and seedling vigor, ensuring uniform stands under water-deficit or saline conditions (Afzal et al., 2005).
  • Enhanced Early Growth: Vigorous seedlings establish faster, suppress weeds, and tolerate early-season stress.
  • Improved Nutrient Uptake: SA promotes root proliferation, facilitating better absorption of N, P, and K.
  • Compatibility in Cropping Systems: In maize-based intercropping or rotation systems, SA helps maintain growth balance and stability.
2.2 Physiological and Biochemical Role
  • Systemic Acquired Resistance (SAR): SA activates SAR, leading to the accumulation of pathogenesis-related proteins that protect against fungal and bacterial diseases (Nazar et al., 2011).
  • Water Regulation: SA-induced stomatal control minimizes transpiration losses, conserving water under drought (Khan et al., 2015).
  • Antioxidant Activation: SA stimulates antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), which reduce oxidative stress (Janda et al., 2014).
  • Photosynthetic Enhancement: SA increases chlorophyll content and stabilizes Rubisco, enhancing photosynthetic efficiency (Fariduddin et al., 2003).
  • Gene Regulation: SA influences gene expression related to stress signaling, protein synthesis, and growth regulation, improving stress resilience.
3. Salicylic Acid in Stress Management

3.1 Drought Stress
SA improves drought tolerance by enhancing root growth, modulating stomatal conductance, and protecting chlorophyll and membranes from oxidative injury (Rao & Davis, 2012).

3.2 Salinity Stress
SA maintains ionic homeostasis by increasing the K⁺/Na⁺ ratio and reducing electrolyte leakage. It supports osmotic adjustment and turgor maintenance under saline environments (Singh & Gautam, 2011).

3.3 Temperature Stress
SA induces the synthesis of heat shock and cold-responsive proteins that stabilize membranes and protect photosynthetic pigments, thereby reducing lipid peroxidation under temperature extremes (Janda et al., 2014; Szalai et al., 2000).

3.4 Biotic Stress
SA-mediated SAR strengthens cell walls and enhances lignification, making maize more resistant to pathogens like rust, leaf blight, and stem rot (Nazar et al., 2011).

4. Benefits of Salicylic Acid Application in Maize

4.1 Agronomic Benefits

1. Improved Germination and Seedling Vigor for better field establishment (Afzal et al., 2005).

2. Enhanced Biomass and Growth: SA increases shoot and root biomass, improving resource allocation (Hayat & Ahmad, 2007).

3. Higher Leaf Area and Photosynthesis: Greater leaf expansion boosts the leaf area index (Fariduddin et al., 2003).

4. Reduced Lodging: Stronger stems improve stand stability under high yields (Wani & Kumar, 2021).

4.2 Physiological and Biochemical Benefits

1. Improved Photosynthetic Efficiency and chlorophyll stability (Janda et al., 2014).

2. Enhanced Antioxidant Defense reducing reactive oxygen species accumulation (Nazar et al., 2011).

3. Improved Nitrogen Assimilation through increased nitrate reductase activity (Fariduddin et al., 2003).

4. Hormonal Synergy with auxins and gibberellins, supporting growth and stress tolerance (Hayat & Ahmad, 2007).

5. Application Methods and Practical Recommendations

Method

Concentration

Application Stage

Benefit

References

Seed priming

0.5–1.0 mM

Before sowing

Improves germination and early vigor

Afzal et al. (2005)

Foliar spray

0.5–2.0 mM

Vegetative to grain filling

Enhances stress tolerance and disease resistance

Khan et al. (2015); Janda et al. (2014)

Soil application

0.5 mM

Early growth or onset of stress

Improves ionic balance and root health

Hayat & Ahmad (2007); Nazar et al. (2011)


For Haryana conditions, seed priming is ideal for drought-prone zones (Hisar, Sirsa), foliar sprays for mixed farming regions (Ambala, Kaithal), and soil application for saline tracts (Mahendragarh, Jhajjar).
6. Field Research Evidence

1. Rao & Davis (2012): Reported higher chlorophyll and biomass in SA-treated maize under drought.

2. Singh & Gautam (2011): Observed enhanced plant height and dry matter under salinity.

3. Khan et al. (2015): Documented SA’s influence on antioxidant enzyme regulation.

4. Afzal et al. (2005): Demonstrated improved germination under saline conditions.
 
7. Future Prospects and Challenges
SA provides a sustainable, cost-effective approach for enhancing maize resilience in Haryana’s semi-arid zones. However, issues like dose sensitivity, cultivar-specific responses, and formulation development require further study. Future innovations such as nano-formulated or slow-release SA could improve efficiency. Integrating SA into nutrient and irrigation management systems can further stabilize maize yields under climatic stress.
 
8. Conclusion
Salicylic acid is a potent bioregulator that enhances maize performance under environmental stresses. Its multifaceted benefits-ranging from antioxidant activation to nutrient uptake and photosynthetic stability-make it an essential tool for stress management and yield enhancement. Region-specific standardization of SA use and integration with precision agronomy practices can further promote sustainable maize cultivation in Haryana.

References

1. Afzal, I., Basra, S. M. A., & Iqbal, A. (2005). The effects of seed soaking with plant growth regulators on seedling vigor of wheat under saline conditions. Journal of Stress Physiology & Biochemistry, 1(1), 6–14.

2. Arfan, M., Athar, H. R., & Ashraf, M. (2007). Does exogenous application of salicylic acid modulate growth and photosynthetic capacity in spring wheat under salt stress? Journal of Plant Physiology, 164(6), 685–694. https://doi.org/10.1016/j.jplph.2006.05.010

3. Fariduddin, Q., Hayat, S., & Ahmad, A. (2003). Salicylic acid influences photosynthetic rate and nitrate reductase activity in Brassica juncea. Photosynthetica, 41(2), 281–284. https://doi.org/10.1023/B:PHOT.0000011962.05991.6c

4. Hayat, S., & Ahmad, A. (2007). Salicylic acid: A plant hormone. Springer. https://doi.org/10.1007/1-4020-5184-0

5. Janda, T., Gondor, O. K., Yordanova, R., Szalai, G., & Pál, M. (2014). Salicylic acid and photosynthesis: Signaling and effects. Acta Physiologiae Plantarum, 36(9), 2537–2546. https://doi.org/10.1007/s11738-014-1620-y

6. Khan, M. I. R., Fatma, M., Per, T. S., Anjum, N. A., & Khan, N. A. (2015). Salicylic acid-induced abiotic stress tolerance and underlying mechanisms in plants. Frontiers in Plant Science, 6, 462. https://doi.org/10.3389/fpls.2015.00462

7. Nazar, R., Iqbal, N., Masood, A., & Khan, N. A. (2011). Role of salicylic acid in regulation of physiological and biochemical processes under environmental stress. In S. Hayat & A. Ahmad (Eds.), Salicylic acid: A plant hormone (pp. 1–25). Springer. https://doi.org/10.1007/978-94-007-6428-6_1

8. Rao, M. V., & Davis, K. R. (2012). Ozone-induced cell death occurs via two distinct mechanisms in Arabidopsis: The role of salicylic acid. Plant Journal, 25(5), 575–587. https://doi.org/10.1046/j.1365-313x.2001.00989.x

9. Singh, A., & Gautam, N. (2011). Protective effect of salicylic acid on maize under salt stress. Journal of Environmental Biology, 32(3), 295–300.

10. Szalai, G., Tari, I., Janda, T., Pál, M., & Páldi, E. (2000). Effects of cold acclimation and salicylic acid on ACC and MACC contents in maize during chilling. Biologia Plantarum, 43(4), 637–640. https://doi.org/10.1023/A:1026736212857

11. Wani, A. B., & Kumar, P. (2021). Salicylic acid-induced abiotic stress tolerance in plants. In M. Hasanuzzaman, M. Fujita, & K. Nahar (Eds.), Plant tolerance to environmental stress (pp. 95–118). Springer. https://doi.org/10.1007/978-981-15-7576-9_5