Versatile Triazole Selenoureas against Pests, Fungi, and Weeds

Plant selenium plays a role in phytoremediation and defends against phytopathogenic microbes and herbivorous insects. However, artificial organoselenides defense (AOSeD) for plant protection has not been developed. In this study, novel N-difluoromethyl triazole selenoureas have been developed as a versatile AOSeD for controlling pests, phytopathogenic fungi, and weeds. The finding showed that such an AOSeD effectively defended against the second-instar larvae of Plutella xylostella and Solenopsis invicta at a lethal dose (LC50) of 5.41 and 7.24 mg/L, respectively. Phytopathogenic fungi, including Guignardia citricarpa, Rhizoctonia solani, Phytophthora infestans, Colletotrichum higginsianum, Pyricularia oryzae, etc., were remarkably inhibited by AOSeD, and the effective concentration (EC50) reached 0.38 mg/L against G. citricarpa. Such AOSeD can also be employed to control weeds, including Echinochloa phyllopogon, Bidens pilosa, Ageratum conyzoides, Praxelis clematidea, and Mikania micrantha. The inhibitory concentration (IC50) toward the root length of A. conyzoides reached 0.54 mg/L. Importantly, AOSeD is safe for tomato plants and Brassica campestris.