International Journal of Horticulture, 2017, Vol.7, No. 31, 288-298
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vineyard soils. Variation in the response and sensitivity of different roots in the absorption of Ca under the
influence of soil pH could be due to root preference and/or the uptake other cations.
Sulphur absorption reduced significantly with increasing levels of soil pH on Dog Ridge (Table 2). While it
increased up to a pH of 7.79 and reduced thereafter on own root, reduced up to 8.48 and increased marginally
thereafter on Dog Ridge (Table 3). Dog Ridge root were more efficient than the rest two and own root was more
sensitive to changes in soil pH, while 110R root was independent of pH in S absorption (Figure 2). Within the pH
range of vineyard soils in the present survey, absorption of Ca and S were opposite to each other on all types of
root (Figure 2). This indicates the mutual antagonism between Ca and S under the condition of pH and free
calcium contents of the vineyard soils.
3.3 Effect of soil electrical conductivity
Electrical conductivity of the soil (ECe), among the chemical characteristics, influenced the highest number of
nutrients studied. It influenced positively the absorption of N on own root; S, Mn and Zn on Dog Ridge and Fe on
110R (Table 2). N absorption increased steadily with increasing levels of ECe on own root, while increased up to
0.62 and decreased thereafter on Dog Ridge but reduced up to 1.12 and increased marginally thereafter (Table 3).
Own root was more responsive to changes in ECe in N absorption. While 110R was more efficient in N
absorption at ECe level less than 0.5 dSm-1 and Dog Ridge at 1.0 dSm-1, own root were more efficient beyond
1.0 dSm-1 (Figure 3).
Absorption of S increased up to ECe of 0.88dSm-1 and reduced thereafter on own root, but increased steadily but
marginally with increasing levels of ECe on the rootstocks (Table 3). Own root were more efficient in S
absorption in the ECe range of 0.5 -1.5 dSm-1, while the rootstocks were more efficient beyond 1.5dSm-1 (Figure
3).
Absorption of Fe reduced with increasing levels ECe up to 0.81dSm-1 and increased thereafter on own root (Table
3). Though the response was positive and steady on 110R, the rate of increase in Fe absorption to unit increase in
ECe was higher on own root than on 110R beyond 1.0dSm-1, consequently own root was more efficient than the
other roots beyond 1.5dSm-1 (Figure 3).
Manganese absorption increased steadily with increasing levels of ECe up to1.76dSm-1 on Dog Ridge, but
decreased up to 0.88dSm-1 and increased thereafter on own root (Table 3). Own root were more efficient in Mn
absorption at lower levels of ECe up to 0.5dSm-1, whereas Dog Ridge was more efficient at higher levels beyond
0.5dSm-1compared to other roots (Figure 3).
Absorption of Zn decreased marginally up to 0.59dSm-1 of ECe and increased sharply thereafter, whereas it
increased at a lower rate after 0. 59 dSm-1 on own root (Table 3). Own root were more efficient up to 1.1dSm-1,
while Dog Ridge beyond that, when compared to other roots (Figure 3). The positive relationship of Mn with ECe
and negative relationship of Zn on Dog Ridge root indicated their mutual antagonism on this rootstock. Similarly,
the nature of response curves of nutrients to ECe was the pointer for mutual antagonism between S and Mn and
synergism between Fe and Mn on own root. Variation in the nutrient interactions on different roots was attributed
to root affinity for nutrients (Downton, 1977; Asher and Ozanne, 1961). Relative contents of soluble salts of
chlorides, sulphates and bicarbonates of potassium, calcium, magnesium and sodium in the soil contribute to the
level of ECe. The specific ion concentration contributing to ECe, its interaction with other nutrient ions seem to be
the reasons for variation in the absorption of nutrients by different roots under varying levels of ECe.
3.4 Effect of free calcium content of soil
Free calcium CaCO3 content of soil influenced K absorption negatively on own root and Dog Ridge, but
positively that of Ca on Dog Ridge. None of the nutrient absorption was influenced on 110R (Table 2). Negative
influence of CaCO3 was observed from 7.38 per cent onwards on own root and from 8.39 per cent on Dog Ridge
(Table-3). Own root was more efficient in K absorption than Dog Ridge at all the levels of CaCO3 in the present
study. 110R root were more efficient than the rest at higher levels (>17 per cent) – Figure 4. Antagonistic effect of
