EVALUATION OF TWO CITRUS ROOTSTOCKS UNDER KAFR EL-SHEIKH CONDITIONS: . b- EVALUATING VOLKAMER LEMON “C.Volkameriana" AS ROOTSTOCK FOR WASHINGTON NAVEL ORANGE CULTIVAR UNDER KAFR EL-SHEIKH CONDITIONS.

This study was carried out during 2001 and 2002 seasons on 8 - year old
Washington navel orange trees budded on Volkamer lemon and Sour orange
rootstocks to evaluate vegetative and root growth. Yield. Fruit quality. leaf and root
mineral contents and ability of the two rootstocks to tolerate salinity. concentration of
some heavy metals of root.leaf.n‘nd.peel and juice of the fruit.
The obtained results showed that. Voikamer lemon produced the highest
values of tree size. tree height. shoot length. number of leaves per shoot. trunk cross
sectional area “TCSA cm " and leaf area than those recorded on Sour orange
rootstock.
Volkamer lemon rootstock also. produced the highest values of root growth i.
e. root length. root density and root dry weight at different depths (30. 60 and 90 cm)
and distances (50. 100 and 150 cm) from tree trunk comparing with those of Sour
orange rootstock.
Washington navel orange tree on Volkamer lemon rootstock had lower Na
and Cl ions in their leaves and roots but had higher levels of proline. carbohydrate and
chlorophyll a. b and its total value than those recorded on Sour orange rootstock.
Fruit set was higher on Volkamer lemon than that on Sour orange rootstock.
This result may due to fruit dropped in May. June and July on Volkamer lemon which
was less than on Sour orange rootstock.
Washington navel orange on Volkamer lemon gave the highest yield as
kgltree and yield efficiency as kglcm2 of TCSA as well as weight kgima of tree canopy
volume compared with the corresponding values on Sour orange.
The tested fruits contained higher values of TSS with less acidity(%) on Sour
orange than both values on Volkamer lemon rootstock.0n the other hand. fruit taken
from trees on Volkamer lemon recorded higher values of fruit length, diameter.
volume. weight. juice volume and find thickness when compared with those recorded
on Sour orange rootstock
Leaf N. K, Ca. Mg, Fe. Mn. Zn and Cu contents were higher on Volkamer
lemon rootstock than those on Sour orange rootstock.
Root N. P. K. Fe. and Cu contents were also higher on Volkamer lemon
rootstock.0n the contrary root Ca. Mg. Mn and Zn values were significantly lower in
concentrations on Sour orange rootstock than these on Volkamer lemon roots.
Additionally. trees on Sour orange rootstock contained higher of Pb. Cd. Se.
Ni and Cr. in their leaves. roots fruit peel and fruit juice than those on Volkamer lemon
 
rootstock.