Assessing the efficacy and residual impact of plant growth retardants on crop lodging and overgrowth: A review

Lodging caused by overgrowth significantly reduces crop yields worldwide annually. Plant growth retardants (PGRts) as a chemical intervention widely adopted in agricultural practices provide an effective strategy to mitigate lodging and control excessive growth. However, the diversity of PGRts and the limited research on their soil environmental safety necessitate comprehensive evaluation. To address this gap, we categorized the primary PGRts commonly used in agriculture and identified potential compounds. Classifying them based on their chemical properties, we reviewed their modes of action, suitability for various crops, and soil residue characteristics. Our findings indicate that quaternary ammonium compounds are highly effective in preventing lodging without leaving soil residues, and moderate dosages have negligible effects on overall yield due to their limited pharmacological properties. Triazole PGRts exhibit commendable efficacy in both lodging prevention and yield enhancement; however, their prolonged soil residue duration may pose challenges for subsequent crop growth. Cyclohexane carboxylic acid compounds demonstrate high efficiency and easy soil degradation, though careful management of Prohexadione-calcium application is necessary to avoid potential soil toxicity. The use of B9 in succinic acid compounds is limited by its high toxicity levels. Furthermore, we critically analyzed the limitations of PGRts and proposed strategies to address these challenges. Our study provides a theoretical basis for the efficient selection and application of PGRs, aiming to achieve high and stable crop yields while minimizing soil environmental risks.