The Role of Plant Growth Regulators and How to Use Them Correctly

Plant growth regulators are a class of substances that are either artificially synthesized or extracted from microorganisms and have activity similar to that of natural plant hormones. Their defining features are that they are used in small amounts and are highly active, so even a very low concentration can noticeably affect plant growth and development. Unlike foliar fertilizers, they do not themselves supply nutrients to crops; instead, they work by regulating physiological processes.

Divided by function, plant growth regulators can be roughly grouped into several major categories: auxins that promote growth, cytokinins that promote cell division, ethylene-type substances that promote ripening and abscission, and regulatory substances such as chlormequat and paclobutrazol that inhibit or delay growth. The direction of action differs considerably between categories, so before use you should first clarify the specific type of product.

In production, their range of applications is fairly broad. Common uses include promoting rooting of cuttings, reducing flower and fruit drop, helping fruit expand and ripen, controlling excessive vegetative growth, and enhancing cold tolerance and stress resistance. Reasonable use helps unify growth and improve fruit set, and has a certain supporting effect on yield and quality.

It should be noted that if such products are used at too high a concentration or at the wrong time, they may instead inhibit crop growth and even cause phytotoxicity. Before application, read the instructions carefully, follow the recommended concentration and method, do not mix them at will with foliar fertilizers or other pesticides, and pay attention to the weather conditions at the time of spraying. Only through scientific and standardized use can plant growth regulators deliver the effects they should.