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Two field experiments were conducted during the spring
season through two successive years, 2007 and 2008, at El-Shiekh
Zowyeid Research Station, Desert Research Center to evaluate the
effect of applying three rates of crop evpotranspiration (ETc)
throughout three growth stages of tomatoes , individually and in
combinations with selected twelve treatments of deficit irrigation and
four levels of N and K fertilization rates on the yield production
.some growth and quality parameters and some water requirements
measures under water and fertilization stress of tomato (strain B,
Lycopersicon esculentum L.) B.
The applied treatments include:
Three deficit irrigation doses (100, 80 and 60 % of crop water
requirement) were applied through three plant growth stages
(development, mid and late growth stages) as follow:
I. D1 = Irrigation with 100 % ETc through the three growth stages.
D2 = Irrigation with 100 % ETc through the development and late
stages and irrigation by 80% ETc at mid stage.
D3 = Irrigation with 100 % ETc through the development and late
stage and irrigation by 60% ETc at mid stage.
D4 = Irrigation with 100 % ETc through the development and mid
sages and irrigation by 80% ETc at late growth stage.
D5 = Irrigation with 80 % ETc at the development stage and irrigate
by 100% through mid and late growth stages.
D6 = Irrigation with 60 % ETc at the development and irrigate by
100% through mid- and late growth stages.
D7 = Irrigation with 60 % ETc through the development and mid
and irrigation with100% at late growth stage.
D8 = Irrigation with 60 % ETc through the development and late
and irrigation with 100% ETc at mid growth stage.
D9 = Irrigation with 60 % ETc through the three growth stages.D10 = Irrigation with 80 % ETc at the development and irrigate by
100% and 60 % at mid-and late growth stages, respectively.
D11 = Irrigation with 80 % ETc through the development and lateseason,
while irrigate with 100% at mid-season growth stage.
D12 = Irrigation with 60 % ETc through the three growth stages.
II. Four fertilization rates as follows::
F1 :100 kg N/fed and 120 kgK2O /fed.
F2 :100 N/fed and 60 kgK2O /fed.
F3 :50 N/fed and 120 kgK2O /fed .
F4 :50 N/fed and 60 kgK2O /fed
The obtained results summed up as follows:
I. Effect of deficit irrigation:
The weight of both fruit yield and fresh shoot, moisture contents
and growth parameters of tomato decreases with increasing deficit
irrigation during the stages of growth, Applying deficit irrigation
during one growth stage is much better than two and three stages.
The weight of dry fruits and shoots showed reversed trend for fresh
weights either fruits or shoot where the dry matter increased with the
less decrease of the applied water (20% ETc) at the late growth stage
Tomato quality fruit parameters (acidity and electrical conductivity
and total dissolved solids) showed positive moral response where,
the values increased with increasing water deficit especially, soluble
solids while the acidity was slightly affected.
The application of deficit irrigation at one growth stage decreased
concentration and uptake of N,P and K in tomato fruits the least
values were achieved by applying 80% ETc in the late growth stage
in both seasons
Applying deficit irrigation at two growth stages decreases the
concentration and uptake of N, P and K with the maximum
decreases when adding 60% ETc . Applying irrigation (80 or 60%) for three growth stages led to the
largest decreases in concentrations and uptake of N, P and K.
The actual evapotranspiration (ETa) of tomato plants was affected
by decreasing the applied water throughout the different growth
The application of deficit irrigation ( 80% ETc) in both
development and mid-season growth stages decreased ETa less
than its application in the development and late season growth
Applying irrigation (80 or 60%) ETc for the three growth stages of
tomato, decreased ETa less than applying 100%
The water use efficiency of tomatoes increased when applying
100% ETc relative to applying 60% ETc for three growth stages
while the magnitude of decrease is less when applying 80% ETc at
the late growth stage relative to development growth stage
Water use efficiency decreased by applying 20% deficit of ETc in
the development stage and late season < development and midseason
< 60% ETc development and the late season< 60% ETc for
the three growth stages
The lowest WUE for dry tomato plants corresponds to 80 % ETc
during the development and mid-season growth stages while the
maximum WUE was confined to the smallest irrigation water
amount , 60% ETc., in the three growth stages.
The highest Weco.. of dry production was achieved by applying
the minimum irrigation water quantity (60% ETc) while the lowest
was obtained when the irrigation water decreased to 80 % ETc at
mid- season growth stage.
II. Effect of fertilization rates:
All tomato growth parameters were affected by the rate of N and K
fertilization where they increased with increasing the rate of added
N while, the impact of K doses was slight but significant. All fresh and dry weights of fruits and shoots , growth and quality
parameters of tomato increased significantly by adding fertilization
The concentrations and uptakes of N, P and K in fruits and shoots
of tomatoes decreased according to decreasing the doses of N and
Increasing the amount of added N and K led to the increase of the
daily actual evapotranspiration in each stage and the whole season
The water use efficiency of tomato increased gradually with
increasing the applied fertilizers rate
Increasing the application of N fertilizer has a pronounced effect on
the increase of WUE compared to the increasing rate of K
The highest Weco. for fresh and dry fruits of tomato is associated
with applying the largest rate of both N and K fertilizers,.
Increasing N application has a considerable effect on increasing the
Weco of tomato compared to the increasing rate of K fertilization.
III. Combined effect of deficit irrigation and fertilization
Firstly, one should to mention that all comparisons were
conducted relative to the control (D1 F1) unless otherwise stated.
The minimum decrease in fresh weight of tomato yield was
obtained by applying D1 F2. Moreover, the decreases were
maximized when tomato plants were irrigated by D12 F4 The yield of dry tomato fruits followed the same trend of the fresh
fruits yield, On the other hand, the slight decrease in irrigation (D4
F1 and D5 F1) caused a significant increase in dry weight.
The fresh and dry tomato shoots followed the same trends already
mentioned for the fresh fruits .
All growth parameters of tomato plants decreased slightly by
applying D4x F1 and this effect was more apparent with decreasing
the applied fertilizers rate
Reducing N fertilization rate led to more correspondent decreases
in all growth parameters, especially when the N fertilizer decreased
to the half dose F3 ( D5 F3 and D6 F3).
Applying D7 F1, decreased plant height, fruit diameter, number of
leaves and leaf area index more than D8 F1
Applying 40 % deficit regime at the three growth stages caused the
highest decreases in all studied parameters relative to 20 % deficit
Applying D3 F1 increased TSS in fruit more than D4 , ,D5 , D6,
D8 and D11 with F1. Also, applying D7 F1 increased EC, pH and
TSS in fruit relative to D11 F١ . Moreover, applying D9 F1
increased remarkably TSS in fruit while, EC and pH were nearly
Applying D5 F1 led to a pronounced decrease in both the
concentrations and uptake of N,P and K in fruit. Likewise, applying
D6 F1 decreases their concentration and uptake in different
magnitudes. Decreases of D2 F1 N,P and K in fruits on applying D2 F1were
almost close to D3 F1 .
Generally, applying an increasing pattern of deficit irrigation with
constant fertilization rate (F1) led to a pronounced decrease of N,P
and K , however, the magnitude of was decrease more
considerable at the higher rates of deficit irrigation .
The minimum ETa value at mid- season growth stage was obtained
when applying D3 F4 in the two seasons.
Decreasing the applied irrigation water depth by 20 % ETc at
development growth stage caused a pronounced decrease in ETa in
Applying 80% ETc at the late growth stage caused a slight decrease
in ETa in the two seasons.
Applying D9 F1 decreased ETa at each of development, mid and
late growth stages as well as total season less than applying (D12
Both development and late growth stages were the most sensitive to
The tomato yield is correlated significantly with plant water
consumption at all growth stages and total season except the dry
fruit in both development and late-season growth stages of the two
The largest decrease of WUE was obtained when plants were
irrigated by 60 % ETc (D6) with applying the lowest fertilization
rate (F4) A slight decrease was recorded for WUE of fresh fruits when plants
were irrigated with 80 % ETc through late growth stage with
applying the highest rate of fertilizers (D4 F1).
Applying 20 % or 40 % deficit irrigation especially, with
decreasing the fertilization rate at mid growth stage caused a
decrease in WUE for the dry weight of fruits with the maximum
decrease at the mid growth stage when applying 40 % deficit
irrigation (D3 F4) .
Applying irrigation by 80% of ETc at development and / or late
growth stages and adding the two higher rates of fertilization led to
increasing WUE of fresh and dry fruits.
Using the applied irrigation water dose at 80 % ETc in conjunction
with high fertilization rate through both development and mid
growth stages (D7) had further decreased WUE for fresh tomato
fruits. Align with this, applying deficit irrigation through both
development and late stages with adding the two higher
fertilization rates increased the WUE of dry fruits .
The largest decrease in WUE by fresh tomato fruits was obtained
when applying high deficit irrigation rate (60 % ETc) and / or
decreasing the fertilization rate through both development and late
Applying 20 % deficit irrigation through both development and
mid- season stages (D7) caused a decrease in WUE especially with
decreasing the fertilization rate in the two seasons upon applying
(D7 F4). In contrast, applying deficit irrigation through both
development and late- season stages with adding the two higher
fertilization rates increased the WUE of dry fruits Applying 20% and 40% ETc deficit irrigation together with N & K
fertilization at all growth stages decreased the WUE by fresh fruits,
especially with decreasing the applied fertilization rate.
The highest Weco of fresh tomato fruits was rendered to 20 %
deficit irrigation at late- season D4 F1 , relative to the lowest Weco.
obtained by applying the D12 F4 in the two seasons. In contrast,
the dry tomato fruits recorded the maximum Weco. when plants
were irrigated by 40 % deficit regime through the studied three
growth stages (D12F2) relative to D12 F4
There were highly significant positive simple correlations among
the fresh and the dry weights of fruit yield and the fruit moisture
content vs soil variables, EC and pH of irrigation water
The fresh weight of tomato yield is highly significant positively
correlated with N fertilization, N and K concentration in fruit and
seasonal ETa while being significant negatively correlated with EC
and pH of soil
The dry weight of tomato yield is highly significant positively
correlated with EC irrigation of water, N,P and K concentrations ,in
fruit and seasonal ETa while being significant negatively correlated
with EC and pH of soil
The moisture content of tomato yield is highly significant
positively correlated with N,P and K concentrations ,in fruit and
seasonal ETa while being significant negatively correlated with EC
and pH of soil .