Rainfall removes active substances from the plant surface, decreasing their concentration within plant tissues and reducing the effectiveness of treatments.
Plant protection product deposits on plant surfaces are constantly exposed to physical, biological and chemical factors that can reduce the biological efficacy of the active substances. For effective control of plant pathogens, plant protection products must have a “correct” persistence on/in plant tissues and must be able to withstand meteorological events such as rain, UV light and temperature.
Rainfall removes active substances from the surface of the plant, decreasing their concentration within plant tissues and reducing their overall bioavailability at doses that are not lethal for pathogens. Therefore, in order to guarantee the effectiveness of the treatments, they must be repeated, thus significantly increasing production costs. Another negative consequence is the fact that the removed substances will reach "non-target organisms", soil and water, in particular, resulting in unnecessary environmental contamination.