Development and In-Field Validation of Fungicide Nanoformulations of Prothioconazole and Tebuconazole and Modified Kraft Lignin

The search for alternatives to conventional agrochemicals presents itself as an excellent opportunity to develop sustainable, carbon-neutral agricultural technologies and to open new businesses. The use of kraft lignin, a renewable material with its chemical modification, is an opportunity to develop advanced and sustainable materials to reduce the negative impact of agrochemicals on the environment by reducing the active ingredient (AI) quantity for application. This work deals with the preparation, characterization, determination of incorporation efficiency (IE), and validation by in-field experiments of three fungicide nanoformulations using lignin-based carriers and prothioconazole (PTZ) and tebuconazole (TBZ) as AI at a mass ratio of 5 g of carrier: 600 mg of AI. The in-field experiments, associated with IE values from 83.2 to 100%, demonstrated the superior performances of the developed nanoformulations, against commercial formulations and isolated AI, to control Asian soybean rust and corn helminthosporiosis. In in-field experiments, the three formulations showed gains in productivity, highlighting PTZ-AMKL with 3030 kg ha–1 for soybean and PTZ-AKL 6438 kg ha–1 for corn, with productivity values above those obtained with commercial fungicide formulations─this behavior was observed also with the severity reduction in plants. Indeed, these new nanoformulations can reduce the quantities of both AI for pest control in order to reach sustainable agriculture by means of decreasing the negative effects from agricultural practices on the environment and public health.