Seed treatment technologies: Effects on physical, functional, and physiological seed quality

Seed treatment is a foundational technology in modern agriculture, designed to protect high-value seeds against initial pest and pathogen attacks, among other benefits, ensuring crop establishment. However, the application of complex chemical formulations, although protective, imposes stresses that can compromise seed quality if poorly performed. The objective of this review is to synthesize current knowledge on chemical seed treatment and critically analyze its impacts on the multiple attributes that define seed performance. The effects of seed treatment on physical quality are discussed, highlighting the risk of mechanical damage during processing, and on physiological quality, focusing on the mechanisms of phytotoxicity that can reduce vigor and germination, especially during storage, as well as all factors that can affect this relationship between treatment and physiological quality. Additionally, the emerging functional quality is addressed, analyzing how seed treatment affects plantability and environmental safety. A critical and often neglected balance exists between protective efficacy and seed integrity; therefore, studies for correct execution of seed treatment are essential for maintaining the physiological quality of seeds. Knowledge gaps, especially regarding the interaction between slurry mixture composition, storage, and initial lot quality, indicate the need for future research focused on safer formulations and optimized application technologies to maximize the benefits of seed treatment without compromising seed quality.