الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
SUMMARY
The present investigation was carried out to study the
effect of irri gat ion at different ava i1abl e soil mo isture
stress, maize cultivars and foliar application of zinc
sulphate on growth, yield and its components, chemical
composition and the water relation of maize plants.
Three field experiments were conducted at Sakha Agricultural
Research Station, Kafr El-Sheikh Governorate. Egypt in
1988, 1989 and 1990 seasons. The selected areas were studied
to determine field capacity. wilting point, bulk density,
mechanical and chemical analysis.
The experimental design was split-split plot with four
replications. The main plots were randomly assigned to three
irrigation levels, the sub-plots to three maize cultivars and
the sub-sub plots to the three zinc sulphate concentration.
The area of each plot was 33.6 ~ (6 x 5.6 m) with a ridges
which were 70 cm apart and 6 m length. The treatments were as
follows:
I. Irrigation treatments:
1. Irrigated when 40% of the avai lable soil moisture was
depleted.
2. Irrigated when 60% of the available soil moisture was
depleted.
3. Irrigated when 80% of the available soil moisture was
depleted.
II. Maize cultivars:
1 . G; za 2.
2. T.W.C.310.
3. Karnak.
III. Zinc sulphate levels:
1 . 0.0%
2. 0.3%.
3. 0.6%.
Maize plants were sprayed twice when aged 30 and 45 days
at a rate of 400 liters solution/feddan. All cultural practices
except factors under study were carried out as common
practices in the area.
To study the growth analysis, samples of maize plants
were taken at random from the second and seventh rows at 60.
75 and 90 days from sowing. Yield and yield components were
dete rmined from a central area of each plot, equa 1
1/300/feddan.
Characters studied:
I. Growth attributes:
1. Dry matter accumulation and distribution/plant.
2. Leaf area/plant (drrf)’
3. Total chlorophyll and earotenoids.
5. Crop growth rate.
6. Relative growth rate.
7. Net assimilation rate.
8. Time of silking.
9. Plant height (em) at harvest.
10. Ear height (em) at harvest.
11. Stem diameter (em) at harvest.
II. Yield and yield components:
1 . Percentage of plants carried more than one ear.
2. Percentage of infection with late wilt disease.
3. Ear length (em).
4. Ear diameter (em).
5. Ear wei ght (g).
6. Number of rows/ear.
7. Number of grains/row.
8. Grain yield/plant (g).
9. Weight of 100-grain (9)·
10. Grain yield (kg/feddan) adjusted to 15.5% moisture.
11. Straw yield (ton/feddan).
III. Chemical composition:
1. Crude protein percentage.
2. Protein yield (kg/feddan).
3. Oil percentage.
4. Oil yield (kg/feddan).
5. Zinc content of ma,~e grains (ppm).
IV. Soil-water relations:
1 • Water consumptive use.
2 . Water use and yield relationship.
3. Water uptake patterns of maize.
4. water use efficiency.
5. Crop coefficient (Kc).
V. Simple phenotypic correlations:
The important results of this study could be summarized
as follows:
I.. Growth. attri butes: .
A. Effect of years:
1. All characters were significantly affected due to years
except stem diameter. The average values of dry
weight/plant, leaf area/plant and leaf area index in the
three stages, carotenoi ds, time of s i1king and plant
height were high values in the third season.
2. The high mean values for chlorophyll a, b, (a+b), crop
growth rate, relative growth rate, net assimilation rate
were detected in the first season.
B. Effect of water stress:
1. The averaS6 values of dry weight/plant at 60, 75 and 90
days after sowing, the percentage of ears at 90 days from
planting, leaf area/plant and leaf area index at 60, 75
and 90 days from sowi ng, ch 1or ophy 11 a. carotenoi ds I crop
growth rate, net assimilation rate, plant height, ear
height and stem diameter were significantly decreased by
increasing available soil moisture depletion from 40% to
80% in the combined analysis of 1988, 1989 and 1990
seasons.
2. There was a significant delay of silking time by ;ncreasing
the 50;1 moisture depletion. Earlier silking was
observed when maize plants were i rrigated at 40% so; 1
moisture depletion.
3. The mean values of the percentage of leaves and stem at
60 days from sowing, the percentage of leaves, stem, ears
and tassel at 75 days after planting, chlorophyll b ,
(a+b), the ratio of chlorophyll (a+b) to carotenoids and
relative growth rate were not significantly affected by
water deficit.
C. Varietal differences:
1. T.W.C.310 cultivar surpassed significantly Giza 2 and
Karnak cultivars in dry weight/plant at 60, 75 and 90
days from sowing, the percentage of stem at 75 and 90
days after sowi ng, 1eaf area/pl ant and 1eaf area index at
75 and 90 days after planting, crop growth rate, plant
height, ear height and stem diameter in the combined
a~3lysis over the three seasons.
2. Karnak cultivar gave the highest values for the percentage
of leaves/plant at 75 and 90 days from sowing,
chlorophyll (a) and number of days to 50% silking.
3. Giza 2 cultivar surpassed significantly the other
cultivars in the percentage of ears and stem/plant at 75
and 90 days from sowing.
4. The differences between the three cultivars under study
were not sign i f icant in 1eaf area/p 1ant and 1eaf area
index at 60 days from sowing, chlorophyll b, (a+bL
carotenoids, the ratio of chlorophyll (a+b) to carotenoids,
relative growth rate and net assimilation rate.
D. Effect of zinc levels:
1. The average values of dry weight/plant at 60 and 75 days
from sow; n9, the percentage of stem and 1eaves at 60 days
from planting, the percentage of stem, ears, and tassel
at 75 and 90 days after sowing time, leaf area/plant and
leaf area index at 90 days after sowing, chlorophyll
content, carotenoids, crop growth rate, relative growth
rate, net assimilation rate, plant height and ear height
were not significantly affected by zinc levels in the
combined analysis over the three seasons.
2. The mean value of dry weight/plant at 90 days from sowing
time, leaf area/plant and leaf area index at 60 and 75
days after sowing and stem diameter were significantly
increased by incr-eas ing 1eve 1 of zinc su 1phate up to
0.3%.
3. Number of days to 50% s ilk in9 was sign if icant 1y decreased
by application zinc sulphate as foliar up to 0.3%.
E. Interaction effect:
1. The percentage of stem and ears at 90 days from sowing
were highly significantly affected by the interaction
between water stress and maize cultivars in the combined
analysis over the three seasons. The highest percentage
of 5tern was 40. 54% , obta ined from i rriga tion at 40%
depletion in available water with T.W.C.310 cultivar,
while the lowest one was 28.96%, obtained from watering
at 60% soil moisture depletion with Giza 2 cultivar. The
highest percentage of ears was (50.41 or 50. 11), obtained
from watering at 40% or 60% depletion of soil moisture,
respectively, with Giza 2 cu1tivar. whereas the other
characters of growth anal ys is were not significant 1y
affected by the interaction between water stress and
maize cultivars.
2. The max imum mean va 1ues of the rat i0 of ch 1orophy 11 (a+b)
to carotenoids was 1.80 mg/dm2 leaf area, obtained from
0.3% zinc sulphate and 40% depletion of soil moisture,
whereas the lowest one was 1.69 mg/drrf 1eaf area, obtained
from 40% soil moisture depletion and foliar
application of zinc sulphate at 0.6%. However, no
” significant difference was obtained from the effect of
the interaction between water stress and zinc level on
the other growth characters.
3. There were sign ificant differences between the mean
va 1ues of ch 1orophy 11 a, carotenoi ds and the ratio of
chlorophyll (a+b) to carotenoids due to the interaction
between maize cultivars and zinc levels in the combined
analysis between the three seasons. T.W.c.3i0 cultivar
with applied 0.3% zinc sulphate gave the highest value of
chlorophyl 1 a and the ratio of ch 1orophyll (a+b) to
carotenoids (2.39 and 1.82) mg/d~ leaf area, respective-
1y. The highest mean val ue of carotenoi ds was 2.37 mg/dnf
leaf area. obtained from applied 0.3% zinc sulphate with
Karnak cultivar.
4. The differences between the percentage of 1eaves and stem
at 60 days from sowing a~d stem percentage at 75 days
from sowing were significantly affected by the interaction
between water stress, cult;vars and zinc levels in
the combined analysis over the three seasons. The other
characters of growth analysis were not significantly due
to the interaction between water stress, maize cultivars
and zinc levels.
II. Yield and yield components:
A. Effect of years:
1. All characters were differed significantly from year to
another except ear length.
2. The high mean values were detected for ear diameter, ear
weight, 100-grain weight, grain yield per plant and grain
yield/feddan in the first season, and plants carry more
than one ear percentage, late wilt disease percentage,
number of grains/row and straw yield ton/feddan in the
second season, number of rows/ear in the third season.
B. Effect of water stress:
1. The effect of water stress treatments on the average
values of plants carried more than one ear percentage,
ear length, ear diameter, ear weight, number of rows/ear,
number of grains/row, 100-grain weight and grain
weight/plant were significant in the combined analysis
over the three seasons.
2. Irrigation after 40% soil moisture depletion gave the
highest value of plants carried more than one ear %
(5.22%), ear length (20.94 cm), ear diameter (5.03 em),
ear wei ght (304.94 g), number of rows/ear (13.80). number
of grains/row (44.70), 100-grain weight (41.27 g) and
grain yield/plant (191 .30g).
3. The average values of grain and straw yield/feddan were
significantly decreased by increasing available soil
moisture depletion up to 80% in 1988, 1989 and 1990
seasons as well as the combined analysis over the three
seasons. The highest decreas~ in the percentage of grain
yield/feddan was 26.41~, obtained from irrigation at 80%
soil moisture depletion when compared with 40% depletion
of available soil moisture in the combined analysis.
3. On the other hand, the percentage of late wilt disease
significantly increased by increasing soil moisture
depletion up to 80%.
c. Varietal differences:
1. The percentage of plants carried more than one ear, late
wilt disease %, ear length, ear diameter, ear weight,
number of rows/ear, number of grains/row, grain
yield/plant, grain yield and straw yield per feddan were
significantly affected by maize cultivars in the combined
analysis over the three seasons.
2. T.W.C.310 cultivar gave the highest values of the
percentage of plants carried more than one ear (6.65%),
ear length (22.34 cm), ear weight (313.27 g), number of
grains/row (48.59), 100-grain weight (41.67 g). grain
yield/plant (191.51 g), grain yield feddan (3792 kg) and
straw yield/feddan (6.83 ton).3. Giza 2 cultivar gave the highest percentage of infection
with late wilt disease. whereas T.W.C.310 cultivar gave
the lowest percentage of infection with late wilt
disease.
4. Karnak cultivar gave the maximum values of ear diameter
(5.15 em) and number of rows/ear (14.59).
5. The differences between Giza 2 and Karnak cultivars were
not signi f -j cant in number of gra insf row. grain
yield/plant and per feddan.
D. Effect of zinc levels:
1 . The differences between the mean values of plants ear r i ed
more than one ear%, ear diameter, number of rows/ear and
number of grains/row were not significant due to zinc
levels in the combined analysis over the three seasons.
2. The mean values of ear length. ear weight, 100-grain
weight, grain yield/plant, grain yield/feddan and straw
yield/feddan were significantly increased by increasing
foliar application of zinc sulphate up to 0.3%.
3. However, no significant difference was obtained by
application zinc levels at 0.3% and 0.6% on the mean
values of 100-grain weight, grain yield/plant and straw
yield/feddan.
4. The average values of infection with late wi lt disease
percentage 5igni fi cant 1y increased by ;ncreas in9 1eve 1 of
zinc sulphate as foliar up to 0.6%.
E. Interaction effects:
1. Insignificant effect of water stress and maize cultivars
interact ion and water stress and zinc 1eve 1s ; nteract ion,
were obtained for yield and yield components.
2. The average values of 100-grain weight, grain yield/plant
and gra in y ie 1d/feddan were sign if icant 1y affected by the
interact ion between cul t ivars and zinc 1eve 1s 1n the
comb ined anal ys is over the three seasons. The highest
mean values of 100-grain weight, grain yield/plant and
per feddan were 42.46, 195.25 g and 3867 kg, respectively,
obtained from T.W.C.310 cultivar with applied 0.6%
zinc sulphate as foliar application.
3. There was a significant difference between the average
values for number of grains/row due to the interaction
between water stress, maize cultivars and zinc sulphate.
The highest value for number of grains/row of T.W.C.310
cultivar was 49.63, obtained from irrigation after 40%
soil moisture depletion with zinc sulphate at 0.6%. While
the lowest one was 39.75, obtained from 80% depletion of
soil moisture and zero sulphate with Karnak cultivar.
III. Chemical composition:
A. Effect of water stress:
1. The mean values of protein percentage was increased by
increasing depletion of soil moisture from 40% to 80
minimum one was 129.33 kg, obtained from irrigation at
80% soil moisture depletion with Karnak cultivar.
2. The highest mean value of protein and oil yield were 342
kg and 225.83 kg/feddan, respectively, obtained from
irrigation at 40% soil moisture depletion and applied
0.3% zinc sulphate as foliar. whereas the lowest ones
were 254 kg and 131.17 kg/feddan. respectively, gained_
from irrigation at 80% depletion in available water
without application of zinc sulphate.
3. The average values of protein and oil yield/feddan were
significantly affected by the interaction between maize
cultivars and zinc levels. Karnak and T.W.C.310 cultivars
with applied 0.3% zinc sulphate as foliar gave the
highest mean values of protei nand oi 1 yie 1d/feddan,
respectively.
4. The interaction between irrigation after 40% depletion in
available water with T.W.C.310 cultivar and applied 0.6%
zinc sUlphate as foliar gave the highest mean values of
protein and oil yield/feddan.
5. Insignificant effect of interaction between water stress
and cultivars was obtained for protein yield per feddan.
IV. Soil-water relations:
1. Seasonal consumptive use amounts increased as the
availability of soil moisture increased in the root zone.
The highest value of consumptive use was 64.43 em when
plants were irrigated at 40% depletion in available
water, while the lowest one was 49.12 cm when watering at
80% soil moisture depletion. Maize cultivars and zinc
applied had no obvious effect on water consumptive use.
2. The highest value of seasonal consumptive use rate was
0.53 em/day accompanied by irrigation at 40% depletion in
available water. Whil~ the lower value was 0.41 em/day
related to irrigation at 80% depletion of soil moisture.
The daily consumptive use increased gradually as plant
growth increased and reached its maximum at about silking
and seed formation. Monthly consumptive use reached its
maximum values during August which represent the period
of maximum demand for water by maize.
3. The relation between consumptive use in cm eX) and maize
grain yield in kg/feddan (Y) for all moisture treatments
was linear and could be described by the following linear
equation:
y = -420.68 + 65.24 X
The grain yield of mai ze increased 65.24 kg/feddan by
increasing one unit (em) of seasonal consumptive use of
maize.
4. The correlation coefficient for the two variables was
significant positive and equal 0.999.
5. Maize plants extracted about 83.33% and 16.67% of its
water needs from the upper and the second foot, respectively,
when maize plants were irrigated at 40% depletion
in available water. Increasing the soil moisture stress,
i.e.t 80% soil moisture depletion resulted in increasing
the percentage of moisture extracted by maize roots from
the second foot (26.44%).
6. The highest water use efficiency value was 1 .40 kg/m3 of
water consumed recorded when maize plants were irrigated
at 40% depletion in available water. whereas the lowest
one was 1.35 kg/m3 produced from wateri ng at 80% soi 1
moisture depletion. T.W.C.310 cultivar utilized water
more efficiency than the other cultivars. Applying zinc
sulphate at 0.3% resulted in producing the highest water
use efficiency than the other concentration.
7. Potentia 1 evapotransp irat ion was estimated by methods
namely modified Penman. Radiation. modified Blaney-
Criddle and the class A pan. Values of potential evapotranspi
rat ion obta ined by the 1ast two methods were lower
than those obtained from Penman and Radiation methods.
8. The crop coefficient (Kc) of maize was estimated by the
previous methods. It was low at the beginning of the
growing season. the increased as a result of the increase
in crop cover. At the end of the season. a reduction in
evapotranspiration rates was noticed as the plants were
going to maturity. Crop coefficient (Kc) values calculated
by using modified Slaney Criddle and the class A pan
methods were hi ghe r than that obta ined by mod if ied Penman
and Radiation methods.
It could be concluded that the calculated value of 0.88
for (Kc) could be used in calculating the consumptive use
of maize in North Delta area as estimated by the aid of
Penman or Radiation methods.
v. Simple phenotypic correlations:
1. Significant positive correlation values were detected
between grain yield/feddan and each of straw yielq
(t/feddan), grain yield/plant, the percentage of plants
carried over one ear, i0C-grain weight, ear length, ear
weight, number of grains/row, plant height, ear height,
stem diameter and dry matter/plant, leaf area/plant and
leaf area index at 75 days from sowing, crop growth rate,
relative growth rate and net assimilation rate.
2. Insignificant positive correlation coefficients were
detected between grain yield/feddan and chlorophyll a, b ,
(a+b) and carotenoids.
3. Insignificant negative correlation value was found
between grain yield/feddan and days to 50% silking.
4. Significant negative correlation value was found between
grain y;eld/feddan and late wilt disease percentage.
It could be recommended from this work that the best
water level for irrigating maize plants when 40% ASt-il.) is
der1eted, applying zinc sulphate as foliar at a rate of 0.3%
W” ;.C.310 cultivar produced higher grain yield/feddan.