Agriculture Reference
In-Depth Information
0.4
0.35
0.3
0.25
0.2
Critical value
0.15
0.1
0.05
0
0
1
2
3
4
5
6
7
8
Year of sampling
Figure 3.11
Exampleofacroplogforpetiolephosphorus(P)analysis.Valuesinyears3and6
less than the critical value can be ignored because the general trend is upward.
Table 3.6
Macronutrient Concentrations in Petioles for Assessing the Nutrient Status of
Grapevines
Low to
marginal
(%)
a
Macronutrient
element
Verydeicient
(%)
a
Deficient
(%)
a
Adequate
(%)
a
High to
excessive (%)
a
N (total)
<0.7
0.7-0.89
0.9-1.2
>1.2
N as NO
3
−
(mg/kg)
<340
340-599
600-1500
>1500
P
<0.15
0.15-0.19
0.2-0.24
0.25-0.5
>0.5
P (Pinot Noir
only)
<0.12
0.12-0.14
0.15-0.19
0.2-0.4
>0.4
K (with
adequateN)
<1.0
1.0-1.7
1.8-3.0
>3.0
Ca
<1.2
1.2-2.5
Mg
<0.3
0.3-0.4
>0.4
Na
>0.5
Cl
>1.0
a
Except where indicated otherwise.
Compiled from Robinson et al. (1997), Goldspink and Howes (2001), and Robinson (2005).
(Thompson seedless) in the United States. These general values have been adapted
to Australian conditions using data from vineyards in South and Western Australia.
Tables 3.6 and 3.7 give petiole concentration ranges for macronutrients and micro-
nutrients, respectively. The critical values occur between the “marginal” and “ade-
quate”categories.
