BACKGROUNDPesticides are indispensable in agriculture and can effectively improve the yields and quality of crops. Due to their weak water solubility, most pesticides need to be dissolved by adding solubilizing adjuvants. In this work, based on molecular recognition of the macrocyclic host, we developed a novel supramolecular adjuvant, called sulfonated azocalix[4]arene (SAC4A), which significantly improves the water solubility of pesticides. RESULTSSAC4A presents multiple advantages, including high water solubility, strong binding affinity, universality, and simple preparation. SAC4A showed an average binding constant value of 1.66 x 10(5) M-1 for 25 pesticides. Phase solubility results indicated that SAC4A increased the water solubility of pesticides by 80-1310 times. The herbicidal, fungicidal, and insecticidal activities of supramolecular formulations were found to be superior to those of technical pesticides, and the herbicidal effects were even better than those of commercial formulations. CONCLUSIONOverall results revealed the potential of SAC4A to improve the solubility and effectiveness of pesticides, providing a new development idea for the application of adjuvants in agriculture. (c) 2023 Society of Chemical Industry.