Summer 2015 - 75
www.turftrends.com
Figure 1
Concentration of H
2
PO
3
-
(ppm) in turfgrass leaf and
root tissue after treatment with 0.35 g m
-2
H
2
PO
3
-
www.gri.gg/bolo302 ).
Grigg Brothers is considered by
many as the leader in current elicitor
research and effective integration
into practical programs designed to
manage turfgrass stress using PM.
Our Proven Foliar fertilizer tech-
nology provides chelated nutrient
options which represent the most
effective, efficient and safe nutrient
source available to turf managers.
Phosphite Fate
An important and recent innova-
tion includes the evaluation of phos-
phite (H
2
PO
3
-
) accumulation in plant
tissue after treatment with PK-Plus
(3-7-18 + 14% H
2
PO
3
-
). This work
demonstrated the systemic nature
of H
2
PO
3
-
once absorbed by leaf
tissue and has led to the most ef-
fective product application rate and
timing recommendations. Phosphite
accumulated in leaf tissue after the
application of 0.35 g H
2
PO
3
-
m
-2
[6
fl. oz./1000 ft2 (M) PK-Plus] and
reached its highest concentration
(4,889 ppm) 48 hr after application
(Figure1).
As expected, H
2
PO
3
-
translo-
cated to root tissue but was found
in smaller concentrations—a range
of 55-492 ppm. Based on field ob-
servations, we estimate the need to
maintain tissue H
2
PO
3
-
concentra-
tions ≥ 1,800 ppm (see dashed red
