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Chapter 1. Nutrient Uptake and Transport Capacities of Different
Mango RootstocksSummary The objectives of thisexperiment were
to investigate the mango cultivars'' abilities in the uptake and
transport of mineral nutrients with special emphasis on the
selection of a high Ca absorbing rootstock . The data will also
be used as a guideline for the choosing of a rootstock for Chiin
Whang which is a deficiency─prone cultivar and to clarify the
relationship between Ca deficiency and pre harvest fruit
deterioration. Results showed a significant difference in Ca
content in leaves among cultivars. Caltivars were arranged
according to the Ca concentration in leaves (from high to low)
after calcium fertilizer was applied. They were listed as Local
Varity, Tai-Known No.1, Keitt, Haden, Phon-Mee, Chiin Whang,
Hon-Long, Irwin and Sensation. The order in the control was
Local Varity, Tai-Known No.1, Phon-Mee, Haden, Hon-Long, Keitt,
Irwin, Chiin Whang and Sensation. Calcium concentration from
high to low in leaves of Chiin Whang after grafting were in the
following order: Hon-Long, Tai-Known No.1, Local Varity,
Sensation, Keitt, Haden, Chiin Whang and Irwin. After pruning
the order were：Local Varity, Tai-Know No.1, Keitt, Sensation,
Hon-Long, Haden, Chiin Whang and Irwin. The magnitude of leaves
calcium concentration of cultivars planting in field were Tai-
Known No.1, Hon-Long, Local Varity , Haden, Sensation, Irwin and
Chiin Whang.The N/Ca of Irwin, Keitt and Chiin Whang leaves was
higher than the other cultivars. Since the above mentioned
cultivars are sensitive to Ca-deficiency, the pre harvest fruit
deterioration may be associated with a high N/Ca in leaves.
Results also indicated that Local Varity and Tai-Known No.1 had
higher Ca uptake and transport capacities. Thus, It is suggested
that these cultivars could be adopted as rootstocks in the
cultivation and breeding of Chiin Whang mango.Chapter 2.
Relationship between Stomata Density, Leaf and Fruit Nutrient
ConcentrationSummary Eight mango cultivars grown in three
different locations were used in the determination of leaf and
fruit mineral nutrient concentrations and the possible relations
between them. Stomata density was recorded with a view to
elucidating the relationship between transpiration and Ca
uptake. Result indicated ''Chiin Whang'' mango had the highest N
content among cultivars in all three locations. A comparasion of
the average leaf nutrient concentration of the 8 cultivars with
that of Florida, U.S.A. revealed that Ca was rather low, a
slight variation in N but no significant differences were found
for the other nutrients. Ca decreased as fruits were measured
from proximal to the distal end, or from peel to the inner
mesocarp. In the different portion of fruit, N was the lowest at
outer mesocarp, P was the highest at distal end and K was the
highest in the inner mesocarp. High K and Cu were found
accumulated in the fruit at the fruit developmental stage. But
high N, P, Mg,Ca, Fe, Mn and B were found in leaves.In both
leaves and fruits, experiment results showed a negative
correlation between P and Ca, K and Zn, Zn and Fe, Cu and Mn.
However, K and Mn, Mg and Cu, Mn and Mn. Zn and Zn, Zn and B
exhibited a positive relationship. Boron and Cu likewise showed
unveiled a positive correlation between leaf and leaf. A
positive correlation was also observed between P and N, Mg and
K, Cu and Zn together with a negative relationship between B and
Fe. A high value of N/Ca, K/Ca and Mg/Ca could be associated
with fruit deterioration. Results indicated Deshehari, Israel
and Man-Moo had more stomata numbers than those of Irwin,
Sensation and Haden. A positive correlation was noticed between
the distribution of stomata and Ca uptake.Chapter 3. Leaf
Carbohydrate and Mineral Concentrations of seedling, Scion and
Rootstock of ''Chiin Whang'' mangoSummary An experiment was
carried out using tips of juvenile twig and were grafted on the
mature rootstock to induce flower bud differentiation. After
successful grafting and further growth, leaves of seedling,
topworking scion and rootstocks were sampled and analyzed for
carbohydrate, mineral nutrients and C to N ratio. Results
indicated that carbohydrate concentration of seedling was rather
stable while those of topworking scion and rootstock increased
rapidly to 30% in March a two-fold increase from October. No
difference was found in soluble sugar content at the early
developmental stage. Soluble sugar swiftly increased in the
topworking scion and rootstock during the flowering period in
March. Starch content was high in seedlings while that of the
rootstock was low with scion in between. A significant decline
was observed at the sampling time in October. As to element
concentrations, Seedling had a high P level as well as Mn and
Cu. Rootstock had relatively lower value of P and Cu as compared
with the seedling and scion. No definite trend was found for the
other elements. Results also indicated seedling leaves had a
higher value than scion and stock at the beginning of
investigation. Carbon to Nitrogen ratio in leaves of topworking
scion and rootstock augmented during blossom in March to 21.6
and 21.9, respectively, and had a similar trend in the changing
process, lowest in October and hit an all-time high in March.It
is concluded that the basis of inducing flower initiation in
seedling after grafting could be the effect of carbohydrate
alone as shown by the significant change in C to N ratio.
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