Table 11
(Continued)
Term
Definition
Unit
Spacing between rows
or
row spacing
In case of single rows: distance from the centre of one row to the next row.
In case of double or multiple rows: distance from the middle of one double/multiple row
to the middle of the next double/multiple row.
m
Spacing within row
(spacing between tree/plants in the row)
Distance from tree/plant to the next tree/plant within a row.
m
Leaf Wall Area (LWA)
The area of the canopy/crown/foliage surface per ha ground area.
Calculated using canopy/crown/foliage height and spacing between rows.
m
2
/ha
Formula:
LWA per ha ground area (m
2
/ha ground area)
=
canopy/crown/foliage height
(m)
9
row sides applied (usually 2)
9
10 000 m
2
/spacing between rows (m)
Tree Row Volume (TRV)
The cubic volume of the rows per ha ground area.
Calculated using canopy/crown/foliage height, mid-width of the canopy/crown/foliage
and spacing between rows.
m
3
/ha
Formula:
TRV per ha ground area (m
3
/ha ground area)
=
canopy/crown/foliage height (m)
9
mid-width of the crown (m)
9
10 000 m
2
/ spacing between rows (m)
Globular Tree Row Volume (GTRV)
The cubic volume of globular trees per ha ground area.
Calculated using canopy/crown/foliage height, the globular diameter and spacing between rows.
m
3
/ha
Formula:
GTRV per ha ground area (m
3
/ha ground area)
=
canopy/crown/foliage height (m)
9
globular diameter (m)
9
10 000 m
2
/spacing between rows (m)
Table 12.
Application-related terms
Term
Definition
Unit
Treated row width
or
spray band width
The width of the horizontally sprayed band, usually indicating the width of the treated rows.
Application directed to the ground
m
Treated canopy/crown height (tCH)
or
treated Foliage Height (tFH)
or spray band height
The height of the vertically sprayed band, usually indicating the height of the treated
leaf wall/crop.
Application directed vertically and/or partly upwards
m
Mid-width of the treated
canopy/crown/foliage
(width at the middle of the treated
canopy/crown/foliage height)
Average maximum distance between the outer leaves of the foliage, measured at the middle
of the treated canopy/crown/foliage height.
m
Treated Leaf Wall Area (tLWA)
The area of the leaf wall/crop actually treated with the plant protection product.
The tLWA may be smaller than the actual LWA, if calculated from a spray band height
lower than the actual canopy/crown/foliage height, e.g. bunch applications in grapevine.
Spray
band
height
Foliage/
Canopy/
Crown
height
(Photograph B. Fiedler)
Basic formula:
tLWA per ha ground area (m
2
/ha)
=
spray band height (m)
9
row sides applied (usually
2)
9
10 000 m
2
/spacing between rows (m)
m
2
/ha
The treated Leaf Wall Area can also be calculated from a row length instead of ha ground
area. This calculation should be limited to efficacy trials since it does not allow conversion
to the actually applied dose per ha.
Formula for trial plots:
tLWA per plot (m
2
)
=
spray band height (m)
9
row sides applied (usually 2)
9
total
length of all plot rows (m).
Both formulas can be used to calculate tLWA for efficacy trials.
m
2
(Continues)
8
Ef
fi
cacy evaluation of plant protection products
ª
2021 OEPP/EPPO,
Bulletin OEPP/EPPO Bulletin
0
, 1–24