System (5) for filling a spray tank (11) with at least one liquid solution (E1, M2, M2 ', M3), comprising: - at least a first tank (80) configured to contain a first liquid solution (M2), - means (64, 94) for temporary connection of the system (5) to the tank (11), - means (75) for incorporating an active material (M1) into the first tank (80) or between the first reservoir and the connection means (64, 94), and - pumping means (70) controlled by a control device (51) and configured to selectively fill the tank (11) with the liquid solution (E1, M2) , M2 ', M3), characterized in that the system (5) comprises a second tank (40) configured to contain a second liquid solution (E1) and also means (40, 50, 51, 70, 75, 80 , 92) of preparing the first liquid solution (M2) that are controlled by the control device (51) and that are configured to prepare this first solution l liquid (M2) in the first tank (80) by mixing the second liquid solution (E1) and the active material (M1) in predetermined proportions (M1 / E1), and by the fact that the means (40, 50, 51, 70, 75, 80, 92) for preparing the first liquid solution (M2) comprise at least, on the one hand, the means (75) for incorporating active material (M1) that are positioned between the first tank (80) and the second tank (40) and, on the other hand, agitated means (82) is configured to keep the first liquid solution (M2) in suspension in the first tank (80).Sistema (5) de relleno de una cuba (11) de pulverizador con al menos una solución líquida (E1, M2, M2', M3), que comprende: - al menos un primer depósito (80) configurado para contener una primera solución líquida (M2), - medios (64, 94) de conexión temporal del sistema (5) a la cuba (11), - medios (75) de incorporación de una materia activa (M1) en el primer depósito (80) o entre el primer depósito y los medios de conexión (64, 94), y - medios (70) de bombeo controlados por un dispositivo de control (51) y configurados para llenar selectivamente la cuba (11) con la
