الفهرس 
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Abstract
Two field experiments were conducted at Nubaria Agric. Res, Sta., in 1995/96 and 1996/97 seasons to evaluate 3 irrigationregimes (including 3 water duties of 1090,1490 and 1890 m3/fad),
applied to 3 bread wheat varieties (Sakha 8, Sakha 69 and Sahel 1)
grown under 3 different N levels (80, 100 and 120 kg/fad).The soil of the experiments is calcareous (31.40/0CaC03) with a sandy loam texture, a very low O.M. content (0.450/0)and a pH value of 8.19.
A split split plot design with 4 replication was used .The main
plots were devoted to irrigation regimes, the sub plots to varieties and
the sub sub plots to N levels.>
The results could be summarized as follows : 1- Plant height: of wheat plants at the harvest was not significantly affected by irrigation regimes in both seasons. Also the 3 varieties did not show significant differences in plant height.
The increase in N level from 80 to 100 kg/fad significantly
increased plant height in the first season.
Significant effects of the interaction between Irrig. x Var , Var. x
Nand Irrig. x Var. x N on plant height in the first season and between
all experimental factors in the second season were observed on plant
height.
Maximum plant height was recorded by Sahel 1 supplied with
the medium water level and receiving 80 kg N/fad. being 105.4 cm in
the first season, and by Sahel 1 grown at the higher water level and
supplied with 100 kg N/fad being 115 cm. in the second season.
2- Spike length: was not affected by irrigation regimes in both
seasons. Sakha 69 cultivar produced longer spikes than Sakha 8
and Sahel1, which were on a par in this trait. The increase in N level significantly increased spike length in
both seasons.
The interaction between Irrig. x N and among Irrig. x Var. x N
in 1996/97 season significantly affected spike length. The longest
spikes in that season were those of Sakha 69 supplied with the lower
water level and receiving 100 kg N/fad, being 9.63 cm.
3- Heading date: was delayed due to increasing the irrigation supply
with significant differences in the first season.
The three tested varieties were of similar heading date in both
seasons. Plants reached heading after 100 and 99 days in 1995/96
and 1996/97 season, respectively.
The increase in N level significantly increased number of days
to 500/0heading in both seasons.
The effects of the interaction between Irrig. x VaL, and Irrig. x
Var. x N on heading date were significant in 1995/96 season,
whereas Irrig. x Nand Var. x N significantly affected heading date in
1996/97 season.
In 1995/96 season, the earliest heading was reached after 95.5
days by Sakha 8 plants supplied with 1090 m3 water/fad and
receiving 80 kg N/fad. On the other hand, Sahel 1 plants supplied
98
with 1490 m3 waterlfad +120 kg Nlfad recorded the latest heading
date, wh\ch was reached after 107.5 days 4- Number of splke/m2: increased by applying the medium water
duty compared with the lower and higher water levels. This increase
was s\gnificant in the first season.
Sakha 8 produced higher spike/m2, followed by Sakha 69,
whereas Sahel 1 was inferior with significant differences compared
with Sakha var\eties.
The increase in N level increased spikeslm2with significant
d\fferences in 1995/96 season.
The interactions between the 3 factors significantly affected
spikeslm2 in the first season. In the second season, Inig. x Var. and
Var. x N had significant effect on th\s tratt, The greatest spikes/m2 in 1995/96 season was obtained by
Sakha 8 supplied by 1490 m3 water + 100 kg Nlfad, being 341.
5- Number of kernels/spike: was significantly higher at the medium
water level compared with the lower level. Applying 1490 m
3/fad significantly increased kernelslspike by 3.57 and 13.86% in the firstand second season, respectively compared with the application of
1090 m3. Sakha 8 was superior in the first season in number of kernels,
Ispike, whereas Sahel 1 was the best variety in this trait in the
second season.
The increase in N application significantly increased
kernels/spikes in both season.
The interaction Irrig. x Var. and Var. x N in the first season and
all interactions in the second season significantly affected this trait.
Combining Sahel 1 + 1090 m3 water + 100 kg N/fad produced the maxinum kernels/spike in 1996/97 season, being 55.25.
6. Weight of 1000 kernels: was not significantly affected by irrigation
levels.
Sakha 8 significantly surpassed Sakha 69 and Sahel 1 in grain
index in the first season.
Also Sakha 69 was significantly superior to Sahel 1 in this trait.
In the second season Sakha 69 was superior to Sahel 1 in this
trait. whereas Sakha 8 was inbetween.
The increase in N level significantly increased grain index the
first season.
The interaction between all experimental factors significantly
affected grain index in the first season, whereas in the second
season Irrig. x Var. as well as Irrig. x Var. x N had significant effects
on grain index.
The heaviest 1000 - kernel weight was recorded in the first
season by Sakha 8 supplied with 1490 m3/water + 100 kg N/fad,
being 44.10 g. and by Sakha 69 supplied with 1890 m
3 water + 80 kg
N/fad, being 49.18 g in the second season.
7. Leaf Area Index <.bAll: at anthesis was increased in both seasons
with increasing water level. Also increasing N application to 120 kg
N/fad enhanced LAI. Sakha 8 was significantly superior in this trait,
while Sahel 1 was inferior and Sakha 69 was inbetween.
All interactions between the experimental factors significantly
affected this trait. The best combination was that including Sakha 8 +
1490 m3/fad water + 80 kg N/fad in the first season, and Sakha 69 +
1890 m3/fad water + 120 kg N/fad in the second season. with an
average value of 2.57 and 3.97, in bah seasons. respectively.
8~ Grain yield lkg/fadt significantly increased when wheat was
supplied with the medium water level (1490 m3/fad). At this level yield
increased by 10.34 and 5.18°/ocompared with the lower and higher
levels, respectively in the first season, corresponding to 11.10 and
9.22°/0 in the second season.
Sakha 8 surpassed Sakha 69 and Sahel 1 in grain yield by
15.95 and 94.58°/01 respectively in the first season. corresponding to
3.56 and 15.830/0 in the second season. Sakha 8 yielded 13.91 and
18.19 ardabs/fad in 1995/96 and 1996/97 season respectively.
Increasing N level significantly increased grain yield in the first
season. but the increase in the second season was not significant.
Raising N level from 80 to 120 kg/ fad increased grain yield by 17.53
and 6.66°/0 in the first and second season. respectively.
The interaction Irrig. x VaL. Irrig. x N. Var. x Nand Irrig. x Var.
x N significantly affected grain yield in the first season, whereas lrrig
xVar .•.Var. x Nand Irrig. x VaL x N had significant effect on grain
yield in the second season.
The interaction between Sakha 8 + 1490 m
3 water + 120 kg N/fad produced the maixmum grain yield 1 being 17.00 and 21.00 ardabs per faddan in the first and second season, respectively.
9- Harvest index Il::!JJ.;. was significantly affected by irrigation level in the first season. The application of 1090, 1490 and 1890 m
3 /fad recorded H.I. of 36.33, 39.67 and 36.78% respectively.
Varieties differed in H.I. in the first season. Sakha 8, Sakha 69
and Sahel 1 recorded 41.00, 37.33 and 34.450/0 H.I. in 1995/96
season. N level had no significant effect on H.I. The interaction Var. x Nand Irrig. x Var. x N in the first seasonand between Irrig x Var., Var. x Nand Irrig. x Var. x N in the second
one , significantly affected H.1. Sakha 8 + 1490 m3 water + 100 kg
N/fad produced the maximum H.I. in the first season, being 48.00
%and combining Sahel 1 + 1090 m3 water + 100 kg N/fad in the second season produced the highest H.I. o~42.00%.
10- Water use efficiency (WUE): significantly reduced by increasing
water level. Applying 1090, 1490 and 1890 m3 water/fed recorded
WUE of 1.16, 0.99 and 0.77 kg grain/m3 water in the first season,
respectively, being 1.72, 1.53 and 1.12 kg in the second season. The
forementioned results showed that WUE was 4.87, 4.15 and 3.22kg
grain per faddan per one mm of applied water in 1995/96 season, in
the first (1090m3 ) , the second (1490m3
) and the third (1890m
3)irrigation regime, respectively.
In 1996/97 season, the corresponding WUE values were 7.20,
6.26 and 4.71 kg grain/fad/ one mm, respectively.
Varieties differed significantly in WUE. Sakha 8 was superior,
Sahel 1 was inferior and Sakha 69 was inbetween. Sakha 8 recorded
WUE of 1.22 and 1.53 kg in the first and second season)
respectively. Sakha 8 produced about 5 kg grain /fad per one mm of
_ applied water in the first season against 6.23 kg grain/fad / one mm
of applied water, in the second season..
The increase in N level increasedWUE in both seasons. All
interactions between the experimental factors showed significant
effects on WUE.
The best combination was that between Sakha 69 + 1090 m3
water + 120 kg N/fad in the first season, and between Sakha 8 +
1090 m3 water + 120 kg N/fad in the second season. The WUE
reached 1.46 and 2.03 kg grain/m3 water, respectively.
11- Nitrogen use efficiency: was higher at the medium water level
with significant differences in the first season.
Varieties varied in NUE. Sakha 8 was the best, Sahel 1 was
the worst and Sakha 69 was inbetween. NUE of 21.05, 18.23 and
11.10 kg in the first season and 27.74,27.06 and 24.21 kg grain Ikg
N in the second one for Sakha 8, Sakha 69 and Sahel 1,
respectively.
The increase in N level reduced NUE markedly. Applying 80,
100 and 120 kg N/fad resulted in NUE of 18.37, 17.62 and 14.40 kg,
respectively in the first season, correspending to 31.30, 25.46 and
22.27 kg grain /kg N in the second season. All effects of the interactions significantly affected NUE. The
best combination was that between Sakha 8 + the medium water
level (1490 m3) + 100 kg N/fad in the first season and between
Sakha 8 + the medium level of water + 80 kg N/fad in the second
season.