WP is a standard abbreviation in this industry for "wettable powder"
paclo is quite stable in the soil, and may persist for years there depending on pH, rainfall, organic matter content ect. It is readily taken up by the roots and translocated via the xylem to the aerial parts of the plant, accumulating in the plant parts that transpire the most.
http://www.inia.es/gcontrec/pub/621-628_Distribution_in_plant_1251882013000.pdf?q=pbz
"The present study showed that 30 days after PBZ
application, most of PBZ was accumulated in the substrate,
while a low amount was absorbed by the different
plant parts (leaves, stems and roots) (Table 2). At the end
of the experiment the amount of PBZ was mainly accumulated
in the plants, while decreased considerably in the
substrate. The highest accumulation of PBZ took place in
the leaves.A quite important amount of PBZ was leached
into the environment at the end of the experiment which
represents a significant environmental problem
"Studies of the PBZ levels in plant during the experimental
period showed that PBZ was taken up through
the roots and translocated via stems to the leaves, where
it accumulated."
"Lehman
et al. (1990) assumed that
PBZ could be stored in perennial plant tissues and was
responsible for long-term growth suppression.
The restrictive effect of PBZ on shoot growth persisted up to
seven months in gardenia (Malorgio
et al., 1993), 13
months in
Pyracantha (Ruter, 1994), 1 year in native
oleander (Bañón
et al., 2001), 2 years in
Eucalyptus
globulus (Hasan and Reid, 1995) and
Rhododendron
catawbiense (Gent, 2004) and 3 years in
Mangifera
indica (Salazar and Vázquez, 1997)."