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The objective of this research was to investigate the effect of EC (electric conductivity) levels of nutrient solution on the growth and yield of tomatoes under the hydroponic system. This research was conducted in a plastic house on the experimental farm of Lampung University, Lampung in Indonesia from April to July 2009. The EC treatments to nutrient solutions were S1 (1 dSm -1), S2 (2 dSm -1), S3 (3 dSm -1), S4 (4 dSm -1), and S5 (5 dSm -1) arranged in a completely randomized design with four replications. The results showed that the highest yield was under S3 (120.8 g/plant), followed by S2 (96.6 g/plant), S1 (89.7 g/plant), S4 (88.4 g/plant), and S5 (75.5 g/plant). The yields of tomato responded to EC levels of nutrient solution in the two ranges of lower and higher EC than 3 dSm -1 . The yield increased as EC of nutrient solution increased from 0 to 3 dSm -1 probably, due to increase of nutrients. On the other hand, the yield decreased as the EC of nutrient solution increased from 3 to 5 dSm -1 probably, due to increase of water stress. So, it can be concluded that the salinity threshold of the tomatoes was 3 dSm -1 . On the other hand, the highest SSC (soluble solid content) was recorded under S5 (7.34 brix), followed by S4 (6.93 brix), S3 (6.44 brix), S2 (6.26 brix), and S1 (6.11 brix). It means that the S5 treatment was the best quality. Among the range of treatments, treatment S3 (3 dSm -1) gave the highest yield, but lower SSC than S4 (4 dmS -1) and S5 (5 dSm -1).
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Journal of Agricultural Engineering and Biotechnology Feb 2014, Vol. 2 Iss. 1, PP. 7-12
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The Effect of EC Levels of Nutrient Solution on the
Growth, Yield, and Quality of Tomatoes (Solanum
Lycopersicum) under the Hydroponic System
R. A. Bustomi Rosadi*1, Masateru Senge2, Diding Suhandy3, Ahmad Tusi4
1,3,4Department of Agriculture Engineering, Faculty of Agriculture, University of Lampung, Bandar Lampung, Indonesia
2Faculty of Applied Biological Science, Gifu University, Gifu, Japan
*1bustomirosadi@yahoo.com; 2senge@gifu-u.ac.jp; 3diding2004@yahoo.com; 4atusi@unila.ac.id
Abstract- The objective of this research was to investigate the effect of EC (electric conductivity) levels of nutrient solution on the
growth and yield of tomatoes under the hydroponic system. This research was conducted in a plastic house on the experimental farm
of Lampung University, Lampung in Indonesia from April to July 2009. The EC treatments to nutrient solutions were S1 (1 dSm-1),
S2 (2 dSm-1), S3 (3 dSm-1), S4 (4 dSm-1), and S5 (5 dSm-1) arranged in a completely randomized design with four replications. The
results showed that the highest yield was under S3 (120.8 g/plant), followed by S2 (96.6 g/plant), S1 (89.7 g/plant), S4 (88.4 g/plant),
and S5 (75.5 g/plant). The yields of tomato responded to EC levels of nutrient solution in the two ranges of lower and higher EC than
3 dSm-1. The yield increased as EC of nutrient solution increased from 0 to 3 dSm-1 probably, due to increase of nutrients. On the
other hand, the yield decreased as the EC of nutrient solution increased from 3 to 5 dSm-1 probably, due to increase of water stress.
So, it can be concluded that the salinity threshold of the tomatoes was 3 dSm-1. On the other hand, the highest SSC (soluble solid
content) was recorded under S5 (7.34 brix), followed by S4 (6.93 brix), S3 (6.44 brix), S2 (6.26 brix), and S1 (6.11 brix). It means that
the S5 treatment was the best quality. Among the range of treatments, treatment S3 (3 dSm-1) gave the highest yield, but lower SSC
than S4 (4 dmS-1) and S5 (5 dSm-1).
Keywords- Salinity; Hydroponics; Deep flow techniques; Tomato; Water stress
I. INTRODUCTION
Tomatoes, the biggest hydroponically produced crop on a worldwide scale, are complex in their physiology and response to
crop management techniques. Obtaining economic yields of high-quality fruit while minimizing the use of pesticides and other
agrochemicals has put commercial tomato growers under increasing pressure, and many are now looking to modified
hydroponic systems where higher profits are possible [1].
Many hydroponic systems can be used in growing tomatoes. But according to [1], nutrient film technique (NFT) and deep
flow technique (DFT) are used in many commercial and amateurish tomato production systems. DFT is less common than
NFT for hydroponic tomato production and relies on a similar system of channels that are filled with a deep flow of nutrient
solution rather than a thin film. DFT systems rely on the introduction of oxygen along the entire length of each growing
channel so that oxygenation rates in the root zone are continually kept high enough for good root growth. As with NFT, the
nutrient solution recirculates continuously and EC, pH and often temperature levels are adjusted at the main nutrient reservoir
[1]. Plants require 16 elements for growth and these nutrients can be supplied from air, water, and fertilizers. The 16 elements
are carbon (C), hydrogen (H), oxygen (O), phosphorus (P), potassium (K), nitrogen (N), sulfur (S), calcium (Ca), iron (Fe),
magnesium (Mg), boron (B), manganese (Mn), copper (Cu), zinc (Zn), molybdenum (Mo), and chlorine (Cl). The key to
successful management of a fertilizer program is to ensure adequate concentrations of all nutrients throughout the life cycle of
the crop. Inadequate or excessive amounts of any nutrient result in poor crop performance [2]. When tomatoes are grown
hydroponically, the EC of the nutrient solution usually employed (7.0 mM K+, 4.0 mM Ca2+, 2.5 mM Mg2+, 1.5 mM NH4+,
12.0mM NO3-, 1.5 mM PO43-, 4.0 mM SO42- plus micro elements) ranges between 2.0 and 2.5 dSm-1 ([3]; Cuartero and Soria,
1997 as in [3]).
Tomato is moderately tolerant to salinity (Fisher, 1967 as in [5]). Bernstein (1964) as in [5] estimated that 50 per cent yield
reduction was obtained at an electrical conductivity of soil extract (ECe) of 8 dSm-1 at 25°C. But according to Hoffman et al.
(1980 in [6]), tomato is moderately sensitive to salinity with salinity threshold of 3.0 dSm-1, and according to Maas (1986 in
[4]), tomato is classified as being “moderately sensitive” to salinity, which means that it tolerates an EC of the saturated soil
extract up to about 2.5 dSm-1 without any yield reduction. Saranga et al. (1991 in [4]) found a threshold between 2.0 and 2.5
dSm-1 and a reduction in yield from 9% to 10% with an increase of 1 dSm-1 beyond the threshold. But Ehret and Ho (1986 in
[4]) reported no significant yield reduction above 7 dSm-1 perhaps, due to the low light intensity and high relative humidity in
their experiments.
Crop salt tolerance is generally assessed as the relative yield response to increasing root zone salinity, expressed as soil or
irrigation water electrical conductivity. In contrast to the general response, where the yield declines after the tolerance
threshold is represented by a single regression line with a species-specific slope (Maas 1990 in [7]). Reference [7] identified
two well defined linear functions with different slopes within this region. In the first region, between 2.5 and 9.6 dSm-1 EC, the
Journal of Agricultural Engineering and Biotechnology Feb 2014, Vol. 2 Iss. 1, PP. 7-12
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slope was 6 % per dSm-1, whereas after 9.6 dSm-1 EC the yield reduction per unit increase in salinity was 1.4 %. According to
[4], yields are reduced when plants are grown with a nutrient solution of 2.5 dSm-1 or higher, and above 3.0 dSm-1 an increase
of 1 dSm-1 results in yield reduction of about 9-10 %. At low solution electrical conductivity (ECs), yield reduction is caused
mainly by reduction in the average fruit weight, whilst the declining number of fruits explains the main portion of yield
reduction at high ECs.
Water stress technique has been used as a method to improve the quality of fruits, such as in tomato production. Water
stress was induced by increasing salinity of nutrient solution. The simplest way of increasing the flavor constituents of tomato
fruit is to increase the EC of the nutrient solution [1]. According to [8], irrigation with saline water can significantly improve
fruit quality in term of SSC, perhaps, acidity of field grown processing tomatoes without depressing marketable yields.
Imposing water stress during fruit growth and fruit ripening stages or from flowering onward reduced marketable yield and
water use efficiency, and increased fruit soluble solids and colour relative to the fully irrigated treatment [9].
Based on the above explanation, it is clear that the tomato plant was moderately sensitive, but the salinity threshold of
nutrient solution of tomato changed between 2 and 6 dSm-1. So, there is a need to know the proper value of salinity threshold
of tomato in water stress application in order to maximize the positive outcome, which is improving the SSC value, and
minimize negative outcome, which is decreasing yield of tomato. In order to know the optimal condition of the water stress
application, this research was conducted to know the effect of salinity (in term of EC) on the growth, yield and quality of
tomato fruits under the hydroponic system.
II. MATERIAL AND METHODS
This research was conducted in a plastic house of the experimental farm in Lampung University, Lampung in Indonesia
from April to July 2009. Tomato cultivar used was Permata. The elevation of the site was 43 m above sea level. The average
air temperature was 26.3°C and the relative humidity was 60.8 %.
The salinity treatments to the nutrient solutions were S1 (1 dSm-1), S2 (2 dSm-1), S3 (3 dSm-1), S4 (4 dSm-1), and S5 (5 dSm-
1) arranged in a completely randomized design with four replications. The hydrophonic system used in this experiment, was
Deep Flow Technique (DFT) in small bucket (10 litres volume) combined with aerator to ensure that oxygenation rate in the
root zone was good. DFT system relies on the introduction of oxygen along the entire length of each growing channel so that
oxygenation rates in the root zone are continually kept high enough to ensure root growth. To maintain the salinity of the
treatment, the nutrient solution was changed weekly to the basic salinity the same as the initial salinity of the treatment. For
example, the nutrient solution of treatment S2 (2 dSm-1) was maintained at 2 dSm-1 from week I (after transplanting to the
hydroponic system) until harvest time. When the EC of the nutrient solution increased to around 2.10 dSm-1 on average, the
nutrient solution was replaced with a new nutrient solution of the same salinity level of the treatment, which was 2 dSm-1.
Before transplanting to the DFT hydroponic system, tomato seeds were seeded in small plastic boxes for three weeks, and
then the tomato seedlings were transplanted into the plastic buckets with soil medium until 6 weeks old. At seven weeks, the
tomato plants were transplanted to the DFT hydroponic system with 1 dSm-1 salinity. Each bucket contained two plants. The
treatments were applied one week after transplanting to the DFT hydroponic system. The nutrition used in this research, was
nutrition package of Joro A & B Mix. Joro A package contained 12 kg KNO3, 16 kg Ca(NO3)2 , 350 g Fe(EDTA), and Joro B
package contained 15 kg KH2PO4, 7.5 kg MgSO4, 5 kg K2SO4, 60 g MnSO4, 50 g ZnSO4, 50 g Borat acid, 50 g CuSO4, 1 g
NaMo. Each package was diluted in 100 liter of water, and mixed. For example, to make the nutrient solution of 2 dSm-1 (S2),
3.3 liter of Joro A and 3.3 liter of Joro B solutions were mixed in 1000 liter of pure water. With the same way, to make the
nutrient solution of the treatments are as follows (see Table 1):
TABLE 1 THE PORTION OF JORO A AND JORO B TO MAKE THE NUTRIENT SOLUTION AS A TREATMENT [10]
Treament EC (dSm-1) Joro A
(litre) Joro B
(Litre) Water
(Litre)
S1 1 1,7 1,7 1000
S2 2 3,3 3,3 1000
S3 3 5,7 5,7 1000
S4 4 7,8 7,8 1000
S5 5 9,9. 9,9 1000
Source: 1. Reference [11] http://joronet.net/produk/pupuk/abmix.htm
2. Based on laboratory experiment
Agronomic variables evaluated in this research were plant height, number of leaves, flowers and fruits, yield, and soluble
solid content (SSC) as a quality indicator. The plant height was measure as the average of two plants in the bucket. The
number of flower was the total number of flower per bucket, the yield was the total fruit weight per bucket, and the SSC was
the value of the fruits sample (five fruits per bucket). Statistical analysis using F-test at 5% significant level, followed by LSD
(Least Significant Different) test at the same level was carried out.
Journal of Agricultural Engineering and Biotechnology Feb 2014, Vol. 2 Iss. 1, PP. 7-12
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III. RESULTS AND DISCUSSIONS
The effect of salinity on the plant height is shown in Table 2. It can be observed that, the tomato plants were stressed under
treatments S4 and S5 from week I and that of treatment S3 started from week III. The plant height of treatment S2 (167.5 cm)
was the highest at week IV, followed by treatment S1 (163.8 cm); however there was no significant difference between these
two treatments. Both of these treatments were significantly different (p<0.05) from treatments S3 (143.3 cm), S4 (129.0 cm),
and S5 (120.8 cm). The above results shows that the plant height was significantly affected by water stress due to the high
salinity of treatments (S3, S4, S5), but was not affected by the low salinity treatments (S1, S2).
TABLE 2 THE EFFECT OF SALINITY ON THE PLANT HEIGHT (IN CM) OF TOMATO PLANTS DURING THE WEEKS VIII TO XI
Salinity level
Week
VIII
IX
X
XI
S1 (1 dSm-1)
92.50
a
122.75
a
145.25
163.75
S2 (2 dSm
-1
) 91.40 a 123.50 a 150.50 a 167.5 a
S3 (3 dSm-1)
89.75
a
115.75
a
135.00
143.25
S4 (4 dSm
-1
) 76.25 b 98.75 b 115.50 c 129.00 c
S5 (5 dSm-1)
74.63
b
91.00
b
106.25
120.75
Note: it means followed by different small letters (a-c) in the same column in each week after transplanting
under different salinity levels are significantly different according to LSD test (p<0.05).
The effect of salinity on the number of leaves is shown in Table 3. It can be observed that, there was no effect of salinity on
the number of leaves. The mean number of leaves under treatment S2 (20.5) was the highest at week IV, followed by S1 (19.5),
S4 (19.0), S3 (18.8), and S5 (16.8).
TABLE 3 THE EFFECT OF SALINITY ON THE NUMBER OF LEAVES OF TOMATO PLANT DURING THE WEEKS VIII TO XII
Salinity level
(dSm-1)
Week
VIII
IX
X
XI
XII
S1 (1 dSm-1)
12.00
a
14.25
a
16.75
a
19.50
a
21.00
a
S2 (2 dSm
-1
) 12.25 a 15.50 a 17.75 a 20.50 a 22.00 a
S3 (3 dSm-1)
13.50
a
15.25
a
17.75
a
18.75
a
19.00
ab
S4 (4 dSm
-1
) 12.00 a 14.00 a 17.00 a 19.00 a 21.50 a
S5 (5 dSm-1)
11.25
a
13.25
a
16.25
a
16.75
a
17.25
b
Note: it means followed by different small letters (a-c) in the same column in each week
after transplanting under different salinity levels are significantly different according to LSD test (p<0.05).
Table 4 shows that the effect of salinity on the number of flowers, especially at week IV and V, treatment S2 was not
significantly different from the other treatments, except treatment S1. The number of flowers of treatment S2 (19.0) was the
highest at week V, followed by treatment S3 (18.3), S4 (18.3), S5 (16.8), and S1 (10.5). Treatment S1 was the smallest among
all the treatments due to its lowest nutrient content. It could be said that treatment S1 was stressed by low nutrition.
TABLE 4 THE EFFECT OF SALINITY ON THE NUMBER OF FLOWERS OF TOMATO DURING THE WEEKS X TO XII
Salinity level (dSm-1) Week
X XI XII
S1 (1 dSm-1) 1.50 b 5.75 a 10.50 b
S2 (2 dSm-1) 7.00 a 13.75 a 19.00 a
S3 (3 dSm-1) 12.25 a 17.25 a 18.25 a
S4 (4 dSm-1) 10.75 a 15.25 a 18.25 a
S5(5 dSm-1) 9.75 a 13.25 a 16.75 a
Note: it means followed by different small letters (a-c) in the same column in each week after transplanting
under different salinity levels are significantly different according to LSD test (p<0.05).
Journal of Agricultural Engineering and Biotechnology Feb 2014, Vol. 2 Iss. 1, PP. 7-12
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Based on Table 5, it was known that the effect of salinity on the number of fruits, especially at week IV and V, the number
of fruits of treatment S3 was not significantly different, compared to the other treatments except treatment S1. The number of
fruits under treatment S3 (18.0) was the highest at week V, followed by S2 (17.5), S4 (16.5), S5 (15.5), and S1 (10.3). It can be
observed from Table 5 that the number of fruits generally decreased at the harvest time (week VII), compared to week V,
because most of the small fruits felled down and number of fruits of the plants under high salinity treatments (S4, S5) and low
nutrient conditions (S1, S2) decreased more sharply than the middle salinity condition (S3).
TABLE 5 THE EFFECT OF SALINITY ON THE NUMBER OF FRUITS OF TOMATO DURING THE WEEKS X TO XII
Salinity level (dSm-1) Week
X XI XII
S1 (1 dSm-1) 1.50 b 5.75 a 10.25 b
S2 (2 dSm-1) 7.00 b 13.75 a 17.50 a
S3 (3 dSm-1) 12.25 a 17.25 a 18.00 a
S4 (4 dSm-1) 10.75 a 15.25 a 16.50 a
S5(5 dSm-1) 9.75 a 13.25 a 15.50 a
Note: it means followed by different small letters (a-c) in the same column in each week after transplanting
under different salinity levels are significantly different according to LSD test (p<0.05).
Table 6 shows that the yield of treatment S3 was significantly different, compared to the other treatments except
treatment S2. The yield of treatment S3 (120.8 g/plant) was the highest, followed by S2 (96.6 g/plant), S1 (89.7 g/plant), S4
(88.4 g/plant), and S5 (75.5 g/plant). S3 treatment was significantly different, compared to S4 and S5 treatments, but there was
no significant difference, compared to S2 treatment. It means that S4 (EC=4 dSm-1) treatment was on a stress condition.
Therefore, the EC at 3 dSm-1 (S3 treatment) was a treshold salinity.
TABLE 6 THE EFFECT OF SALINITY ON THE NUMBER OF FRUITS, YIELD, AND SOLUBLE SOLID CONTENT (SSC) OF TOMATO PLANT
Salinity level (dSm-1) Week XII
Total fruit
Number 5 % Yield (gr) 5 % SSC (brix) 5 %
S1 (1 dSm-1) 5.50 b 89.65 b 6.11 d
S2 (2 dSm-1) 7.25 b 96.57 a 6.26 d
S3 (3 dSm-1) 10.00 a 120.82 a 6.44 c
S4 (4 dSm-1) 6.50 b 88.39 b 6.93 b
S5(5 dSm-1) 6.25 b 75.54 b 7.34 a
Note: it means followed by different small letters (a-c) in the same column in each week after transplanting
under different salinity levels are significantly different according to LSD test (p<0.05).
Based on Table 2 to Table 6, it can be observed that the treatments S4 and S5 were under water stress condition due to the
high salinity (4 dSm-1 and 5 dSm-1, respectively) from week I after transplanting to the hydroponic system, and continued to be
stressed until the harvest time based on the plant height and yield results (fruit weight). Treatment S3 started to be under stress
condition from week III according to the plant height data, but recorded the highest yield and was significantly different from
the other treatments except treatment S2. Based on Table 6, it can be seen that the yield responsed to EC levels of nutrient
solution under the two lower and higher ECs than 3 dSm-1. The yield of tomatoes increased as EC of the nutrient solution
increased from 0 to 3 dSm-1 probably, due to increase of nutrients. On the other hand, the yield decreased as EC of the nutrient
solution increased from 3 to 5 dSm-1 probably, due to increase of water stress. So, it can be concluded that the salinity
threshold of the tomato was 3 dSm-1. It means that the result of this experiment was the same with the statements as in [4],
Maas Hoffman (1977 in [7]), and [7]. According to Hoffman et al. (1980 in [6]), the salinity threshold of tomato was 3 dSm-1
and according to Maas (1986 in [4]), the salinity threshold of tomato (based on saturated soil extract) was about 2.5 dSm-1. It
means that this experiment was good enough for estimating the salinity threshold of tomatoes under the specific conditions
examined here (using mixed nutrition solution of Joro A and joro B).
The relationship between the EC levels of the nutrient solution (ECs) and the yield were expressed by the following two
quadratic relationships.
1) between 0 to 3 dSm-1 y = 8.65x2 - 19.1x + 100
2) between 3 to 5 dSm-1 y = 9.75x2 - 101x + 335
Journal of Agricultural Engineering and Biotechnology Feb 2014, Vol. 2 Iss. 1, PP. 7-12
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Where, Y = Yield (gr) and X = ECs (dSm-1)
The relationships are very different, compared to the result of Maas and Maggio as mention before; that is single linear line
and two linear functions with different slopes. The differences in the results are perhaps due to the different salinity method.
Maas and Maggio measured the salinity by saturated soil extract method which was known as ECe, and this experiment
measured the salinity of nutrient solution which was known as ECs. Based on the curve above (Fig. 1), it was known that the
yield increased sharply from 8% to 25% with the increased of 1 dSm-1 below the “threshold (3 dSm-1)”, and the yield decreased
sharply from 10% to 50% with an increase of 1 dS m-1 beyond the “threshold (3 dSm-1)”.
Fig. 1 The relationship between the EC nutrient solution and yield of tomato
The effect of salinity on the SSC value is shown in Table 6. It can be observed that increasing the salinity level relates to
increasing the SSC or increasing the quality of tomato fruits. The SSC of treatment S5 (7.43 brix) was the highest, followed by
treatment S4 (6.93 brix), treatment S3 (6.44 brix), treatment S2 (6.26 brix), and treatment S1 (6.11 brix). Treatments S4 and S5
were actually under stress condition from week I (after transplanting to the hydroponic system), and continued to be stressed
until harvest time, but the quality of tomatoes of these treatments as shown by SSC results, were significantly different from
treatment S3 and the quality of tomatoes of treatments S4 and S5 were better than treatment S3. It means that the result of this
experiment was the same with the result of the experiments conducted by [5, 8, 9], and [10] as mentioned before that tomatoes
grown under water stress condition will produce fruits with high SSC value.
IV. CONCLUSIONS
1. The plant height was significantly affected by water stress due to high salinity of nutrient solution (S3, S4, S5), but was
not affected by low nutrient solution (S1, S2).
2. The number of leaves was not significantly affected by EC levels of nutrient solution, but number of flowers was
significantly affected by low nutrient (S1).
3. The number of fruits generally decreased at the harvest time (week VII) compared to week V, because most of the small
fruits felled down, and number of fruits of the plants under high salinity (S4, S5) and low nutrient conditions (S1, S2)
decreased more sharply than the middle salinity condition (S3).
4. The treatment S3 started to be in stress condition at week III according to the plant height results, but its yield was the
highest and significantly different (p<0.05)from the other treatments except S2 treatment.
5. The yield of tomatoes increased as EC of nutrient solution increased from 0 to 3 dSm-1 probably, due to increase of
nutrients. On the other hand, the yield decreased as EC of nutrient solution increased from 3 to 5 dsm-1 probably, due to
increase of water stress. So, it can be concluded that the salinity threshold of the tomato was 3 dsm-1. under the specific
conditions examined here (using mixed nutrition solution of Joro A and Joro B)
6. Increasing the salinity level relates to increasing the SSC or increasing the quality of tomato fruit.
7. Among the range of treatments, treatment S3 (3 dsm-1) gave the highest yield, but lower SSC than S4 (4dms-1) and S5
(5dsm-1).
ACKNOWLEDGMENT
Thanks to: 1) Director General of Higher Education, Department of National Education, Republic of Indonesia for donating
to this experiment, and 2) Teguh Wiyono, who was very helpful in running this experiment.
Journal of Agricultural Engineering and Biotechnology Feb 2014, Vol. 2 Iss. 1, PP. 7-12
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REFERENCES
[1] L. Morgan, Hydroponic Tomatoes, Massey University, New Zealand, 2003.
[2] G. J. Hochmuth, and R. C. Hochmuth, Nutrient Solution Formulation for Hydroponic (Perlite, Rockwool, NFT) Tomatoes in Florida,
University of Florida, HS796, 2012.
[3] J. Cuartero and R. Fernandez-Munoz , Tomato and salinity,Sci. Hortic, vol. 78, pp. 83-125, 1999.
[4] J. Shalhevet, B. Yaron, Effect of soil and water salinity on tomato growth,Plant and Soil, vol. 39, pp. 285-292, 1973.
[5] L. G. James, Principles of Farm Irrigation System Design, John Wiley and Sons, Inc., 1988.
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Environmental and Experimental Botany, vol. 59, pp. 276-282, Elsevier, 2007.
[7] J. P. Mitchell, C. Shennan, S. R Grattan and D. M May,Tomato fruit yield and quality under water deficits and salinity,” J. Amer. Soc.
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and quality,” Hort Science, vol. 38, pp. 1389-1393, 2003.
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[10] http://joronet.net/produk/pupuk/abmix.htm. April, 14, 2009.
... This translated into a reduced total yield (Table 3), while the unmarketable yield increased in stressed plants. Other researchers have also reported that high EC of nutrient solution leads to a decrease in yield and deterioration of yield quality [56,57]. Available research results prove that high EC reduced the total yield of lettuce grown in hydroponic systems [58,59]. ...
... Rubio et al. [60] also found no effect of NaCl-induced salinity on TSS, while other researchers reported a decrease in TSS in bell pepper fruits after application of sodium sulphate and sodium chloride [63]. On the other hand, Rosadi et al. [57] found the highest concentration of TSS in tomato fruits when the nutrient solution with EC 5 dS·m −1 . If the application of a eustressor in the form of a high EC activates signaling pathways leading to the production of a higher content of biologically active compounds in the fruit, this may not lead to a reduction in yield. ...
Article
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Hydroponic cultivation using organic, fully biodegradable substrates that provide the right physical properties for plant growth and development is now the future of soilless production. Despite the high productivity and strict control of production conditions in this method, excessive salinity of the substrate often occurs. However, recent research results indicate that salinity at a high enough threshold can improve yield quality, while prolonged exposure to too high EC, or exceeding the safe EC threshold for a given species, leads to reduced quality and reduced or even no yield. The aim of this study was to determine the effect of biodegradable lignite substrate (L) and eustressor in the form of high EC nutrient solution (7.0 dS‧m−1) on morphological and physiological parameters, as well as the quality and yield of cucumber (Cucumis sativus L.) in hydroponic cultivation compared to the mineral wool substrate (MW). The MW/high EC combination showed a significant reduction in shoot diameter by nearly 6% compared to the MW/control EC combination. The stomatal conductance (gs) and the transpiration rate (E) were also significantly reduced in this combination. The present study indicates that the effects of eustressor application vary depending on the growing medium used, and more favorable effects in terms of yield quality were obtained using biodegradable lignite substrate. The high EC of nutrient solution combined with lignite substrate (L/high EC) significantly increased in cucumber fruit the content of β-carotene, lutein, chlorophyll a, chlorophyll b and the sum of chlorophyll a + b by 33.3%, 40%, 28.6%, 26.3% and 26.7%, respectively, as compared to MW/high EC combination.
... Amjad et al. (2014) showed a linear decline of the absorption of macro and micro ions by fruit as EC and truss position become higher. The plant growth and fruit yield began to decline when the nutrient solution exceeded EC 2.54.0 mS/cm (Bustomi et al., 2014). In previous studies, EC 5.5 m/.cm treatment reduced the tomato yield by 22.4~31.1%, ...
... The plant height, stem diam eter, leaf size were significantly decreased ( Fig. 3 and 4). Bustomi Rosadi et al. (2014) mentioned that the plant height was significantly affected by high salinity due to water stress. Ashraf et al. (2021) also reported that tomato plants grown under salinity stress in the presence of 200 mg N kg 1 in different NH4 + :NO 3 ratios showed a variable decline in growth in terms of plant height, plant girth, and stem diameter com pared to no salinity treatment (respective controls). ...
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Salt stress often can enhance fruit quality of tomatoes. Seawater is one of the substrates used by growers. However, utilization of seawater on tomato production is difficult in the hinterland as it is far away from the seaside. Some “onsen” water also show high salt concentration (2%). Therefore, it could be also used as a substrate of salt stress treatment. In this study, salt stress was provided by Yupoka “onsen” water, and the effects of different nutrient ECs on plant growth and fruit quality of tomatoes were investigated. Tomato plants ‘Reika’ were grown in pot soil, and nutrients with EC 2, 4, 8 and 12 mS/cm were applied at the time of irrigation. The fruits were harvested at turning stage until the 3rd truss. Soil salinity attained EC 3.6, 6.7, 12.8, and 15.6 mS/cm. SSC, organic acid, dry matter and NO3-increased by 50, 79, 50 and 27%, respectively at EC12 mS/cm while, weight, size, and water content decreased up to 40, 20, and 4%, respectively. However, fruit cracking did not occur apparently. Most of the plant growth parameters were reduced.
... La tolerancia a la salinidad depende de la especie o cultivar y de los niveles a los que son sometidas las plantas (Goykovic & Saavedra del Real, 2007). Este efecto coincide con lo reportado en Solanum lycopersicon L. por Bustomi et al. (2014), donde a partir de una CE de 3 dS m -1 se disminuyó el número de hojas. En el cultivo de fresa también se reportó un comportamiento similar, donde una CE de hasta 1,6 dS m -1 aumentó el NH, en cambio, se redujo a partir de 1,8 dS m -1 (Bagale, 2018;Gallace et al., 2017). ...
... En la población erguida se presentó el mayor efecto al disminuir en promedio 16,84 %; mientras que en el decumbente la reducción fue del 8,02 %. Un comportamiento similar fue observado por Bagale (2018) en fresa, en donde al aumentar la CE disminuyó el rendimiento; por el contrario, Bustomi et al. (2014), en el cultivo de Solanum lycopersicon L., observaron un aumento constante en el REND con una CE de 1 a 3 dS m -1 , pero una reducción a una CE mayor. Lo anterior sugiere que el efecto de la CE está determinado por el material genético, ya que entre especies y entre variedades de la misma especie, se puede observar una respuesta diferencial a la salinidad (Dorai et al., 2001;Navarro et al., 2006;Villarreal et al., 2002). ...
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Introducción. Jaltomata procumbens (Cav.) J. L. Gentry, de uso alimenticio, se considera una especie semi-domesticada (poblaciones que han tenido un proceso de selección artificial pero aún tienen la capacidad de sobrevivir y reproducirse sin la intervención del ser humano) y que cumple con los criterios para su futuro uso. Objetivo. Evaluar caracteres agronómicos de dos poblaciones de J. procumbens, en invernadero e hidroponía. Materiales y métodos. La investigación se realizó en el Colegio de postgraduados, Campus Montecillo, Texcoco, Estado de México, de julio a diciembre de 2019. Se aplicaron los siguientes tratamientos en un sistema hidropónico abierto: dos poblaciones (erguida y decumbente), tres niveles de conductividad eléctrica (CE): 1, 2 y 3 dS m-1 y dos niveles de poda (con y sin poda). Las variables evaluadas fueron: altura de planta (AP), diámetro de tallo (DT), número de hojas (NH) y de racimos (NR), flores por racimo (FLR), frutos por racimo (FR), peso de fruto (PF), rendimiento (REND) y lecturas SPAD. Resultados. Para ambas poblaciones, su cultivo en condiciones de invernadero e hidroponía promovieron el desarrollo en altura de planta, diámetro de tallo y peso de fruto. Se observó una variabilidad dentro y entre poblaciones para poda y conductividad eléctrica; el cultivo a 3 dS m-1 registró la menor altura de planta y el mayor diámetro de tallo, mientras que con 1 dS m-1 se obtuvo el mayor rendimiento; para el tratamiento con poda, los valores más altos se presentaron en flores por racimo, frutos por racimo y peso de fruto. Conclusiones. Ambas poblaciones presentaron el potencial para ser consideradas en estudios en ambientes controlados.
... Oliveira et al. (2022) Performance of colored bell pepper... It was observed that the increase in nutrient concentration resulted in lower TY of bell pepper cultivars, and this reduction is due to morphological and physiological damage, caused by the reduction in the osmotic potential of the nutrient solution to the production components in less tolerant cultivars (Azarmi et al., 2010;Bustomi et al., 2014;Shimul et al., 2014;Liu et al., 2014), as the reductions in root development, leaf development, chlorophyll content and consequently yield. For MY, the nutrient solution concentration of 75%, when analyzed among cultivars, led to higher yields for Beti-R (22.66 t ha -1 ) and Sucesso (16.49 ...
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Knowledge on the nutritional requirement of the crop under cultivation systems adapted to local realities, in addition to the adequate availability of nutrients in nutrient solution, is of fundamental importance both for plant growth and for the production of quality fruits. Thus, the objective of this study was to evaluate the production performance of colored bell pepper cultivars in an open hydroponic system under different concentrations of nutrient solution. The experiment was carried out in a greenhouse at IFAL, Piranhas Campus, in a completely randomized experimental design with four replicates and in split plots, with plots containing three concentrations of nutrient solution (75%, 100% and 125%) and subplots containing three bell pepper cultivars (All Big, Sucesso and Beti-R). Concentration of nutrients at 75% of the standard nutrient solution differed from the other concentrations for plant height, stem diameter, leaf area and fresh and dry mass of the plant. The total number of fruits and number of marketable fruits were higher in the Beti-R and Sucesso hybrids when subjected to concentrations of 75% and 100%, respectively. The total yields of the Beti-R and Sucesso hybrids were higher at the concentration of 75%, with maximum values of 24.19 t ha-1 and 17.11 t ha-1 , respectively. The concentration of 100% of the standard solution promoted higher results for the All Big cultivar.
... The reduction in leaf area, specific leaf area and specific leaf weight occurs due to acclimative morphological changes of the plant to reduce the saline stress damages, since the saline ions accumulation reduces the turgor in leaves, decreases gas exchange, limiting photosynthesis and, consequently, leaf expansion . The negative effect of saline stress on the growth of tomato plants has been observed by other authors (Rosadi et al., 2014;Win et al., 2018;Khalid et al., 2020). ...
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Crop salt tolerance is generally assessed as the relative yield response to increasing root zone salinity, expressed as soil (ECe) or irrigation water (ECw) electrical conductivity. Alternatively, the dynamic process of salt accumulation into the shoot relative to the shoot biomass has also been considered as a tolerance index. These relationships are graphically represented by two intersecting linear regions, which identify (1) a specific threshold tolerance, at which yield begins to decrease, and (2) a declining region, which defines the yield reduction rate. Although the salinity threshold is intuitively a critical parameter for establishing plant salt tolerance, we focused our interest on physiological modifications that may occur in the plant at salinity higher than the so-called tolerance threshold. For this purpose, we exposed hydroponically grown tomato plants to eight different salinity levels (EC = 2.5 (non-salinized control); 4.2; 6.0; 7.8; 9.6; 11.4; 13.2; 15.0 dS m−1). Based on biomass production, water relations, leaf ions accumulation, leaf and root abscisic acid and stomatal conductance measurements, we were able to identify a specific EC value (approximately 9.6 dS m−1) at which a sharp increase of the shoot and root ABA levels coincided with (1) a decreased sensitivity of stomatal response to ABA; (2) a different partitioning of Na+ ions between young and mature leaves; (3) a remarkable increase of the root-to-shoot ratio. The specificity and functional significance of this response in salt stress adaptation is discussed.
Nutrient Solution Formulation for Hydroponic (Perlite, Rockwool, NFT) Tomatoes in Florida
  • G J Hochmuth
  • R C Hochmuth
G. J. Hochmuth, and R. C. Hochmuth, Nutrient Solution Formulation for Hydroponic (Perlite, Rockwool, NFT) Tomatoes in Florida, University of Florida, HS796, 2012.