الفهرس 
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Abstract
Two field experiments’ were conducted at Nubaria Research Station,
Agricultural Research Center, Egypt, during 1995 and 1996 seasons to
study the effects offour N levels (0, 35, 90 and 135 kg/fed), two P levels (0
and 30 kg P20s/fed) and three FYM levels (0, 20 and 40 ton/fed)on the
growth, grain yield and its components, and chemical contents of leaves and
kernels of S.c. 122.
The soil type was calcareous and sandy clay loam in texture with a
CaC03 of about 23%.
A spilt-split plot design with four replications was used, the main plots
were devoted for FYM levels, the sub-plot for P levels and the sub-subplots
for the N levels. Sub-sub-plot area was 21 m2 (11300 fed). Planting
was done on 19 and 21 June in 1995 and 1996, respectively. The preceding
crop was wheat in both seasons. Harvest was undertaken on 20 October in
both seasons. The results of the experiments could be summarized as
follows:
I. Effect of N levels
1. The increase ill N level from zero to 45, 90 and 135 kg/fed
significantly increased plant height, ear height, area of the topmost
ear leaf, number of ears/plant, ear length, ear diameter, ear weight,
number of rows/ear (in the first season), number of kernels/row,
weight of 100 kernels, shelling percentage and grain yield/fed. The
highest value of these traits were generally recorded at the highest N
level.
, 2. The increase in N level significantlyreduced number of days to 50%
tasseling and silking in both seasons. The earliest flowering was
reached at the highest N level.
3. The increase in grain yield due to the increase in N level was an
indication for the vital role of this nutrient. Maize grain yield was
1.79, 3.38, 3.73 and 4.40 ton/fed in 1995 season at zero, 45, 90 and
135 kg N/fed, respectively. The corresponding values of grain yield
in 1996 season were: 1.51,2.87,4.19 and 4.54 ton/fed, respectively.
The highest N level induced an increase in grain yield of 145 and
200% in the first and second season, respectively compared with the
check treatment.
4. The increase in N level significantly increased N, P and K percentages
in leaves at 90 days from planting in 1995 season, while the effect of
N level on these contents was not significant in 1996 season.
5. The increase in N level significantly affectedN% and protein content
in grain in both seasons. The highest N and protein %were recorded
at the highest N level. The crude protein % increased from 9.06 at
the control level to 9.22, 9.87 and 10.37% with the increase in N
level to 45, 90 and 135kg/fed, respectively on the average of both
seasons.
6. Increasing N level significantly increased P and K percentages in
kernels in 1995.
7. N. uptake increased markedly with the increase in N level. On the
average of both season,N uptake was 17.15,34.49,51.37 and 65.42
kg/fed at the N level of zero, 45, 90 and 135 kg/fed, respectively .
8. Nitrogen sue efficiency has been reduced with the increase in N level
on the average of both seasons.N use efficiency valued 29.70,23.58
and 20.75 kg grain/kg N at the N level of 45,90 and 135 kg/fed,
respectively. This result indicates the efficiency of the highest N
level in calcareous soil to produce high grain yield.
9. N recovery has been slightly reduced as the N level increased. On the
average of both season, applying 45, 90 and 135 kg N/fed recorded
apparent N recovery of39.20, 37.97 and 35.76%, respectively.
II. Effect of P levels
1. Applying P at 30 kg P20y’fed significantly increased plant height (in
1996), ear height, leaf area of topmost ear, number of ears/plant, ear
weight (in 1995), shelling percentage (in 1995) and grain yield/fed.
2. P application did not significantly affect ear length, ear diameter,
number of rows/ear, number of kernels/row and 100-kernel weight in
both seasons.
3. Applying P at 30 kg P20s/fed significantly increased maize grain
yield/fed by 26.68, 10.43 and 18.31% in 1995, 1996 and the
combined average, compared with the control, respectively.
4. Applying P at 30 kg P20s/fed significantly increased N content in
leaves (in 1995) and N content in grain (in 1995).
5. P application did not significantly affect P and K contents in leaves
as well as in kernels in both seasons.
6. Applying P at 30 kg PzOs/fedmarkedly increased N uptake in grain
where an increase of 19.46% in N uptake was recorded on the
average of the four N levels.
7. N use-efficiency increased as a result of P application. On the
average of both seasons, P at 30 kg P20s/fed increased N use
efficiency by 10.00, 4.65 and 4.79% at the N level of 45, 90 and 135
kg/fed, respectively.
III. Effect of FYM
1. Application of FYM significantly increased plant height, ear length
(in 1995), area of the topmost ear leaf (in 1996), number of
ears/plant, ear diameter (in 1995), ear weight, 100-kernel weight (in
1995), shelling percentage and grain yield/fed.
2. FYM did not significantly affect tasseling and silking dates, ear
length, number of rows/ear, and number of kernels/row.
3. Applying 20 ton FYMlfed significantly increased grain yield by 9.88,
23.44 and 32.79”10 in 1995, 1996 and the combined average,
respectively.
4. FYM application significantly increasedN% in leaves (in 1995),N%
in grain (in 1995),P% in grain (in 1996) and protein content in grain
(in 1995).
5. The application of FYM did not significantly affect P and K contents
in leaves and K% in grain.
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IV. Interaction effects
1. The results indicated that N x P had a significant effect on:
• Tasseling date (in 1996).
• Silking date (in 1996).
• Ear length (in 1996).
• Ear weight (in the combined average).
• Shelling percentage (in 1995, 1996 and the combined average).
• Grain yield/fed (in 1995).
The highest values were generally recorded by combining the highest
levels ofN and P.
2. Significant effects of N x FYM were recorded on the following
characters:
• Plant height (in the combined average).
• Leaf area of topmost ear (in 1996).
• Ear length (in 1996).
• Ear diameter (in 1996).
• Ear weight (in 1996).
• Shelling percentage (in 1995 and the combined average).
• Grain yield/fed (in 1996 and the combined average).
The highest values of these traits were recorded by combining 135 kg
N/fed and 40 ton FYMlfed. Generally, the response of most of the
studied characters to FYM was quite evident where no N was
applied, while at the higher N levels, the effect of FYM was greatly
reduced.
3. Significant interaction effect between P x FYM were observed on:
• Ear length (in 1996).
• Grain yield/fed (in 1995 and the combined average).
The highest values were generally recorded by combining the highest
levels ofP and FYM.
4. Significant interactions ofN x P x FYM were recorded on:
• Leaf area of the topmost ear leaf (in 1996).
• Ear length (in 1996 and the combined average).
• Ear diameter (in the combined average).
• Number of kernels/row (in 1996 and the combined average).
In general, the highest values were generally recorded by combining
the highest levels of three factors.
In conclusion, the results indicated clearly that the highest grain yield
was obtained by applying 135 kg N + 30 kg P20S + 40 ton FYM, being
about five tons per feddan in both seasons.