Mineral Nutrition Status of Valencia Orange


can be attributed to any one element. However, a highly signifi-
cant correlation was found between fruit size and the .itrgen
and potassium contents of fruit. The influence of nitrogen-po-
tassium ratio discussed earlier in relation to leaf analysis was
also observed in fruit size. The multiple regression equation
(Y = 3.001-0.293X, + 0.163X,) indicated that increased nitro-
gen content (X,) of fruit inhibited fruit size, whereas increased
potassium content (X,) increased fruit size. The influence of
nitrogen is nearly twice as strong as that of potassium. .-
erally speaking, fruits high in potassium and low in nitrogencon-
tents had the largest size. The next largest sizes were composed
of fruits relatively low in both nitrogen and potassium contents,
followed by fruits high in both elements. Finally, the smallest
fruits are those with low potassium and high nitrogen contents.

TABLE 24.-A SUMMARY OF THE CORRELATIONS AND REGRESSIONS OF FRUIT
 QUALITY ON MINERAL CONTENTS OF LEAF AND FRUIT BASED ON 161 PAIR
 OF VALUES.


 Fruit
Quality (Y)

Rind texture*





Soluble Solids




Acid .................


Ratio


 Mineral
 Element

Nitrogen

Phosphorus

Magnesium


Nitrogen

Phosphorus

%/ Dry Matter

Phosphorus

Magnesium

; Dry Matter


......... 1 Potassium

 Magnesium


Vitamin C ......


Nitrogen

Phosphorus

Potassium


Com-
ponent

Leaf
Fruit
Leaf
Fruit
Leaf
Fruit

Leaf
Fruit
Leaf
Fruit
Fruit

Leaf
Fruit
Leaf
Fruit
Fruit

Leaf
Fruit
Leaf
Fruit

Leaf
Fruit
Leaf
Fruit
Leaf
Fruit


Correlation
 Coeffi-
 cient (r)

 0.058 n.s.
 0.456**
 0.086 n.s.
 0.388**
 -0.519**
 -0.626**

-0.080 n.s.
-0.273**
-0.279**
-0.557**
 0.735**

 -0.341**
 S-0.383** I
 -0.210**
 -0.247**
 0.713"**

-0.016 n.s.
-0.583:**
 0.276**'
 0.302**

 0.011 n.s.
 -0.595** "
 -0.330**
 -0.736**'
 -0.197 n.s. I
 -0.205** '


Regression (i)


26.30 +

26.71 +
28.62-
28.69 -


11.71 -
14.08 -
14.84 -
 4.36 +

 1.67-
 1.51-
 1.23-
 1.38-
-0.21 +


1.216X

7.018X
2.830X
11.310X


2.298X
19.222X
33.783X
0.382X

4.389X
4.348X
0.346X
2.640X
0.069X


18.08 5.542X
9.15 + 3.687X
7.78 + 26.200X

80.62 35.302X
70.09-160.833X
80.67-322.957X

64.67 12.009X


 The calculations of rind texture and
on 117 pair of values.
 ** Statistical significance.
 n.s. Not significant.


mineral compositions of leaf and fruit were based