However,
Carre-Missio et al. (2009) reported that the activities of glucanases,
chitinases, and peroxidases increased in the presence of
Hemileia vastatrix regardless of the presence of Si in the nutrient
solution. Datnoff et al. (2007) also reported that Si is not translocated
from older to newer leaves or even from one application
site to another. Thus, to ensure reduced disease intensities, possibly
via osmotic effects, potassium silicate should be continually applied
to all organs of the plant to be protected (Rodrigues et al., 2009,
2010), but this type of application is extremely difficult to achieve
in commercial plantations, as in the case of strawberry. Treatments
with additional applications of potassium silicate after chitosan
application had an antagonistic effect, due perhaps to increased
moisture, which favored infection by B. cinerea.
Overall, the results of the present study showed that chitosan
application in the field and at postharvest is a promising strategy
for the management of gray mold in postharvest strawberry fruits.