الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
The present study was conducted during two consecutive
seasons 1987 and 1988 at the nursery of the Faculty of Agriculture ,
Moshtohor . Kalubia Governorate. This investigation aimed to study
the following :-
1- The possibility of reducing the dominant habit and downward
direction of tap root of pecan seedlings in favor of increasing
root branching and better root distribution in the soil.
2- Enhancing thc rate of vcgctative growth in the nursery to
shorten the period required to produce a nursery tree.
3- Encouraging the branching of tree top in favor of forming a
more compact tree form.
Therefore , the fonowing five experiments were included in the study :
Experiment I: Effect of growth regulator sprays
on growth 01 pecan seedUngs.
Two _ year _ old pecan seedlings were transplanted in early
February of both seasons. These seedlings were sprayed three times
Le, May, June and July. The growth regulators used were 50 ppm
TIBA, 500 ppm 6-furfuryl amino purine, 1000 and 2000 ppm SADH
in both seasons. Beside, 1000 and 2000 ppm CCC were used in the
first scason only. Meanwhile, 50 ppm 6- benzyle amino purine , 100
and 200 ppm PP998 treatments were applied in the second season
only. These treatments were arranged in complete randomized
design. The vegetative growth measurements were done from the
beginning of growth and repeated at monthly intervals till September.
Other growth parameters were done ’ln mid - January.
The obtained results reyealed that :-
a-50 ppm TIBA treatment increased the number of lateral
shoots per seedling , shoot branching angle , number of leaves per
seedling , number of lateral roots , total seedling dry weight shoot
and root dry weights as well as root : shoot ratio. Such treatment
caused significant reduction in shoot length without any effect on root
length.
b - 1000 and 2000 ppm SADH treatments relatively increased
number of lateral shoots and roots per seedling , total seedling dry
weight , shoot and root dry weight as well as root : shoot ratio.
Meanwhile , SADH treatment decreased shoot length , shoot
branching BDgles and number of leaves per seedling ( especially low
concentration ).
c - 500 ppm 6- turturyle amino purine increased number of
lateral shoots per seedling, total seedling dry weight , shoot and root
dry weights as well as root : shoot ratio. Meanwhile. this treatment
reduced shoot length.
d _ 1000 and 2000 ppm CCC treatments increased number of
lateral shoot per seedling , number of leaves per seedling ( especially
at high concentration) , and number of lateral roots per seedling .
e _ 100 and 200 ppm PPsas treatments ( applied in the second
season only ) increased number of lateral shoots per seedling ,
( mainly 200 ppm ) , shoot branching angle , number of lateral roots
per seedling. total seedling dry weight. root and shoot dry weights as
wen as root: shoot ratio.. Meanwhile t both concentrations of PPa;38
highly reduced shoot length especially at high concentration. Other
growth parameters did not show any response to PPaea treatments.
f _ 50 ppm 6- benzyle amino purine improved shoot branching
angles , and root dry weight Meanwhile, this treatment failed to
affect other growth parameters • when it was applied in the second
season.Generally t it is safe to conclude that spraying pecan seedlings
with 50 ppm TIBA was the most promising treatment in enhancing
better distribution of pecan seedling growth.
Experiment II: Effect of nutritional sprays
on growth of pecan seedlings.
In early February 1987 , 2 - year - old pecan seedlings were
transplanted at nursetY rows at 50 em. apart. These seedlings were
sprayed three times in May, June and July with one of the fonowing
nutritional sprays :-
a - Tap .ater spray ( control)
b - 500 ppm Zinc sulphate
c - 5000 ppm urea
d - 5000 ppm pata.sium sulphate
These treatments were arranged in complete randomized
design with three replicates and each replicate included three
seedlings. The same growth measurements of experiment (I) were
done.The obtained result. could be summarized - folio•• :-
I - Seedling growth:
a - Both potassium sulphate and urea sprays were superior in
enhancing most of the growth parameters of pecan seedlings Le.
number of lateral shoots per seedling, total seedling dry weight , root
and shoot dry weights as well as root: shoot ratio.
Meanwhile • potassium sulphate and urea sprays effect in
reducing shoot length increase could probably be due to the increase
in number of lateral shoot&
b _ Potassium. sulphate sprays surpassed urea sprays in
improving the branching angles whUe urea sprays surpassed potassium
sulphate treatment in improving stem girth. However, the remaining
growth parameters were not statistically affected.
e _ 500 ppm zinc sulphate sprays increased number of lateral
shoots per seedling, shoot branching angle, total seedling dry weight,
root dry weight and root: shoot ratio. Other growth parameters were
not affected by this treatment.
2 - Leaf nutrient content:
a _ Potassium sulphate sprays improved leaf K , Mg and Zn
contents.
b _ Zinc sulphate sprays increased leaf zinc content only.
e _ Urea sprays tncreased leaf N •K , Mg and Zn contents.
By analysing the results of Experiment (II) • one can generalize
that 5000 ppm potassium sulphate and 5000 ppm urea were the most
effective nutritional sprays in enhancing growth parameters of pecan
seedlings under the experimental conditions. Experiment III: Effect of mycorrhlzae fungi
on growth of pecan seedlings.
In February 1987 , wooden boxes were tmed with a mixture of
sand and clay at the ratio of 1 : 1. The soil was disinfected with 2 %
formalin solution. The soil of the firSt group of boxes was inoculated
in mid _ January with Glomus rDIflcrt1CaJPus fungi. whl1e the second
one was inoculated with Glomus austral/! fungL Meanwhile, the
third group of boxes was left without inoculation 8S control. Moreover
•the fourth group of bos.es was filled with unsterilized soil as a general
controL Seedlings with pnmed roots at 15 em. below the crown were
planted in the previously prepared boxes. The treatments were
arranged in complete randomized design.
The obtained results reycaled that :-
8 _ Glomus IIUStrs1/! fungi proved to be more effective in
improving seedling growth parameters as it greatly increased lateral
shoots per seedling, number of leaves per seedling • root length •
number of feeder roots per seedling. total seedling dry weight • shoot
and root dIy weight& Meanwhile. it reduced the ratio of root : shoot
dry weight
b _ Glomus JDIICJY1CSIPU8 fungi showed to be less effective in
improving seedling growth. However, it increased shoot length •
root length • number of feeder roots per seedling , total seedling dry
weight • shoot and root dry weights. Other growth parameters did
not show any response to mycorrhlzae inoculation.
c - Soil sterilization failed to improve any growth parameters of
pecan seedlings.
It could be concluded from Experiment (III) t that growth of
pecan seedlings respond well to soil inoculation by mycorrhizae
Glomus BustraJe fungi proved to be more effective than G1o.-!DUB
macrt1C1l1pusin improving growth of pecan seedlings in the nursery.
Experiment IV: Response 01 pecan seedlings to soil
treatment witb some cbemtcals.
In February 1987 t wooden boxes. 100 X 75 X 50 em. ( length ,
width’ height) were filled with a mixture of sand and clay at the ratio
of 1 : 1. The soU was subjected to the following treatments :-
a - Silver nitrate was applied at the rate of OJJ7 moles I m2
surface area t above the base of the box by 5 em. t then the boxes were
completed with the soiL
b - Zinc sulphate was applied at the rate of 2.0 moles , m2
surface area t above the base of the box by 5 em. • then the boxes were
completed with the soiL
c - SollJeft without any chemical treatment as a control
1 - year - old pecan seedlings with pruned roots at 15 em. below
the crown were transplanted in the previously prepared boxes.
The treatments were arranged in complete randomized design.
The obtained results revealed that :
Silver nitrate and zinc sulphate treatments at the concentrations
used in this experiment failed to exert a root pnming effect on pecan
seedlings. However they affected seedling growth parameters as they
increased number of leaves per seedling and total seedling dry weight
only. Moreover. zinc sulphate treatment increased root length and
root dry weight
Evaluating results of experiment (IV)• it is easy to say that sUver
nitrate and zinc sulphate treatments improved some growth
parameters of pecan seedlings. However. these treatments failed • at
the concentrations applied • to exert the expected root pruning effect
by killing the root tip at a certain depth.
Experiment V: Response of pecan seedlings
to some root treatments.
In both 1987 and 1988 seasons , 1 - year - old pecan seedlings
were root pruned at 15 em. below the crown • then , they received
one of the fonowing treatments :-
a - Planting directly without treatment ( control ).
b - Wounding the base of the seedling roots by applying two
opposite cuts ( 2 em length ).
c _ Wounding and dipping seedling roots in 1000 and 2000 ppm
Indole butyric acid ( lBA ).
d _ Wounding and dipping seedling roots in 500 and 1000 ppm
Naphthalene Acetic Acid ( NAA ).
e _ Wounding and dipping seedling roots in 600 ppm Benomyle.
!_ Wounding and dipping seedling roots in 1000 ppm lBA +
eoo ppm Benomyl.
g _ Wounding and dipping seedling roots in 500 ppm NAA+ 600
ppm Benomyt
h _Wounding and dipping seedling roots in 1000 ppm IBA +
500 ppm NAA+ 600 ppm Benomyl
These treatments were arranged in complete randomized
design. The obtained results could be summarized as follows :-
a _ Root shortening + wounding increased number of leaves and
number of lateral roots per seedling and total seedling dry weight.
Meanwhile • it reduced root length and root: shoot ratio.
b _ Root shortening + wounding + 1000 or 2000 ppm IBA
treatments were morc cffcctivc as they increascd numbcr of leaves
and number of lateral roots per seedling , root length • total seedling
dry weight • shoot and root dry weights. Meanwhile. shoot length
was re4lJced when 1000 ppm IBA W8B used. Anyhow. the high the
lBA concentration. the more was improving effect on seedling growth.
c _ ( Root shortening + wounding + 600 ppm Benomyl + 1000
ppm lBA ) • ( root shortening + wounding + 600 ppm Benomyl + 500
ppm NAA) , and ( root shortening + wounding + 600 Benomyl + 1000
lBA + 500 ppm NAA ) treatments increased number ot leaves and
number of lateral roots per seedling , total seedling dry weight , shoot
and root dry weights. The last mentioned treatment exerted more
effect than the others.
from Experiment (V)• one can conclude that root shortening +
wounding + dipping in 2000 ppm lBA solution is the most promising
root treatment In improving growth ot one - year- old pecan seedlings.