Plant Biostimulants and Micronutrient Management for Crop Quality Enhancement: A Comprehensive Review
Akashi Sarma *
Department of Plant Breeding & Genetics, Assam Agricultural University, Jorhat, Assam 785013, India.
Gayatree Hazarika
Department of Plant Breeding & Genetics, Assam Agricultural University, Jorhat, Assam 785013, India.
*Author to whom correspondence should be addressed.
Abstract
The escalating global demand for food production, coupled with the imperative for sustainable agricultural practices, has necessitated innovative approaches to enhance crop quality whilst minimising environmental impact. Plant biostimulants and micronutrient management represent two complementary strategies that have gained significant scientific and commercial attention in recent decades. These approaches improve crop quality, enhance nutrient use efficiency, and increase plant resilience to environmental stresses. This comprehensive review examines the current state of knowledge regarding plant biostimulants, including humic substances, seaweed extracts, protein hydrolysates, and microbial inoculants, alongside micronutrient management strategies, particularly foliar applications of zinc, iron, boron, and manganese. The review synthesises evidence from peer-reviewed literature published between 2005 and 2026, drawing upon studies conducted across diverse agroecological zones and crop species. The physiological and biochemical mechanisms through which biostimulants enhance nutrient use efficiency, stress tolerance, and crop quality parameters are critically evaluated. Furthermore, the synergistic interactions between biostimulants and micronutrient applications are explored, highlighting opportunities for integrated nutrient management strategies. The regulatory landscape governing biostimulants, particularly the European Union Regulation 2019/1009, is discussed in the context of market development and product standardisation. Emerging research directions, including precision agriculture applications and the development of next-generation biostimulant formulations, are identified. The review concludes by addressing current limitations in the field and proposing future research priorities to advance the understanding of biostimulant-micronutrient interactions for sustainable crop quality enhancement. Future studies should focus on standardising biostimulant formulations, validating field efficacy across diverse environments, and further elucidating their molecular mechanisms and long-term impacts on soil health and crop productivity.
Keywords: Plant biostimulants, micronutrients, humic substances, seaweed extracts, foliar application, nutrient use efficiency, biofortification