International Journal of Horticulture, 2017, Vol.7, No. 31, 288-298
289
receiving varying levels of nutrients. The organic carbon content of the soils in the selected vineyards was 2.57 ±
1.08 per cent, pH 7.76 ± 0.48, EC 0.61 ± 0.42 dSm-1 , CaCO3 16.2 ± 4.2 per cent and Exchangeable sodium
percent 7.77 ± 1.82. All the vines selected for the study were planted at 3.0 x 1.8 m, trained to extended Y trellis
and pruned to have 30±2 canes/vine. One hundred petioles of leaves opposite to flower clusters were collected at
full bloom from each vineyard and soil samples from 15-30 cm depth at 60 cm away from the vine stem at back
pruning before the application of fertilizers. N, P, K, Ca, Mg, S, Na, Fe, Mn, Zn, Cu contents in petiole and soil
samples; and organic carbon, pH, EC, CaCO3 and ESP in soil samples were estimated following the standard
analytical methods suggested by the AOAC. The ratio of petiole nutrient content to that of soil was calculated in
order to normalize the nutrient absorption and termed “nutrient absorption index” for each nutrient.
Correlations of soil chemical characteristics with the absorption index of nutrients, multiple regression of nutrient
absorption index on chemical characteristics and the quadratic equations for the significant relation of soil
chemical characteristics with nutrient absorption index were calculated by the Microsoft Excel data analysis
package. Significance of the coefficients of the soil chemical characteristics in each regression equation was tested
by their respective t-stat values. Optimum value of each chemical characteristic (X-opt.) was calculated by the
formula; X-opt= –b/2c, where ‘b’ is the coefficient of X and ‘c’ the coefficient of X2 in the respective quadratic
function and the maximum absorption index for each nutrient (Y-max.) was derived by substituting the X values
in the corresponding function.
3 Results and Discussion
Multiple regression analysis revealed that, all the soil chemical characteristics, namely organic carbon (OC), pH,
EC, CaCO3 and ESP together influenced the absorption of all the nutrients studied, except Ca and Cu in vines on
own root; N, P and Cu on Dog Ridge; and Ca, Mg, Na and Cu on 110R. Absorption of K, S, Fe, Mn and Zn was
influenced on all roots, whereas Mg and Na on own root and Dog Ridge; N and P on own root and 110R; and Ca
on only dog Ridge. Nutrient absorption was influenced most on own root followed by Dog Ridge and 110R roots
as evidenced by their determination coefficients. N followed by Zn, P and K were the most influenced nutrients
on own root, while K, Mn and Zn on Dog Ridge; and Fe, N, K and Zn on 110R. All the soil chemical
characteristics were ineffective in the absorption of Cu in vines on any root. Roots of Thompson Seedless and
110R were similar in their absorption of Ca but differed in Mg absorption. While Mg absorption was not
influenced on 110R, it was on own root. Dog Ridge roots differed with other roots in respect of the absorption of
N and P; while 110R in Na (Table 1). Lack of influence of the soil chemical characteristics in the absorption of
any nutrient on any root could be due to the greater availability of the nutrient and/or the higher affinity of the
roots for it. Organic carbon contributed positively towards the determination of absorption of N, P, K and Fe on
own root and K on Dog Ridge, but negatively in case of Mn and Zn on Dog Ridge; and N and K on 110R. pH
contributed positively in the determination of Ca, Mg, Na and Zn on own root, Ca and Na on Dog Ridge; and N
and K on 110R, while negatively in case of P, K, S, Fe and Mn on own root; K and Fe on Dog Ridge; and Fe and
Mn on 110R. EC contributed positively in the determination of absorption of S on own root; Mg, Fe, Mn and Zn
on Dog Ridge; and Fe, Mn and Zn on 110R, but negatively in case of Ca and Mg on own root; Na on Dog Ridge
and P on 110R. ESP contributed positively in the case of Mn on own root and P on 110R, but negatively in case of
N on own root and Zn on 110R (Table 1). Variation in the contribution of chemical characters on different roots is
elucidated by the variation in the absorption of nutrients under their influence in the following paragraphs.
3.1 Effect of organic carbon
When the individual effect of soil chemical characteristic on the absorption of nutrients on different roots is
considered, organic carbon (OC) content of soil influenced the absorption of total nitrogen and sulphur in vines on
their own root. None of the nutrients was influenced by it either on Dog Ridge or 110R rootstocks (Table 2).
While the absorption of total nitrogen increased steadily with increasing levels of OC on own root, it decreased on
110R and increased on Dog Ridge up to 3.03 per cent (Table 3). Response of Dog Ridge in the absorption on N to
additional levels of OC was more than own root up to 3 per cent. 110R was more efficient than Dog Ridge under
low levels of OC up to 1.8 per cent and own root up to 2.7 per cent, whereas Dog Ridge was more efficient
above1.8 per cent (Figure 1). OC being the indicator of organic matter in the soil (Jackson, 1958) and promoter of
