Productive and physiological responses of jambu (Acmella oleracea) under nutrient concentrations in nutrient solution

Abstract

In the last years, jambu has become popular and greatly appreciated, due to its remarkable taste. Thus, hydroponically cultivated jambu is promising, since it achieves better yield and production quality. The aim of this study was to evaluate the effect of ionic concentration in nutrient solution on growth, productivity and gas exchange of jambu. The experimental design was completely randomized, with five treatments and four replicates. The treatments consisted of variations of ionic concentration using the nutrient solution proposed by Hoagland & Arnon (25, 50, 75, 100 and 125%). The length of the main stem, stem diameter, number of inflorescence, leaf area, fresh and dry biomass (shoot, root and inflorescence), photosynthesis, stomatal conductance, transpiration, internal CO2 concentration, Ci/Ca ratio and instant carboxylation efficiency were evaluated. Ionic concentrations significantly affected the studied variables, except the stem diameter, the internal CO2 concentration and the Ci/Ca ratio. The number of inflorescences and the leaf area grew linearly with maximum values (37.8 units plant-1 and 1650.8 cm2 plant-1, respectively) obtained in ionic concentration of 125%. Maximum responses were observed for shoot fresh and dry mass (63.9 and 6.9 g plant-1), root fresh and dry mass (16.7 and 2.0 g plant-1) inflorescence fresh and dry mass (11.0 and 1.8 g plant-1), respectively, at ionic concentration of 125%. Liquid photosynthesis, stomatal conductance, transpiration and instant carboxylation efficiency achieved maximum responses of 17.9 µmol CO2 m-2 s-1, 0.3 mol H2O m-2 s-1, 6.3 mmol m-2 s-1 and 0.06 with estimated concentrations of 84, 70, 80 and 83% of ionic strength, respectively. Thus, we concluded that the ionic concentration of 125% is indicated to obtain a greater biomass accumulation.

Full text

65
Research
Horticultura Brasileira 39 (1) January - March, 2021
Acmella oleracea, popularly
known in Brazil as “jambu”, is a
condiment plant from the Amazon of
great importance for gastronomical
and medicinal purposes, mainly in
Para State (Sampaio et al., 2019). This
plant belongs to Asteraceae family,
and it is also known as “agrião-do-
Pará”, “agrião-do-norte”, “agrião-do-
Brasil”, “abecedaria” and “jambuaçu”.
It is a small, semi-erect growth habit
plant, measuring 30-60 cm tall, with
SAMPAIO, IMG; SILVA JÚNIOR, ML; BITTENCOURT, RFPM; SANTOS, GAM; NUNES, FKM; COSTA, VCN. 2021. Productive and physiological
responses of jambu (Acmella oleracea) under nutrient concentrations in nutrient solution. Horticultura Brasileira 39: 065-071. DOI: http://dx.doi.
org/10.1590/s0102-0536-20210110
Productive and physiological responses of jambu (Acmella oleracea) under
nutrient concentrations in nutrient solution
Italo MG Sampaio 1
ID
; Mário L Silva Júnior 1
ID
; Ricardo FPM Bittencourt 1
ID
*; Gabriel AM dos Santos 1
ID
;
Fiama KM Nunes 1
ID
; Vivian CN Costa 1
ID
1           

gmail.com
ABSTRACT
In the last years, jambu has become popular and greatly
appreciated, due to its remarkable taste. Thus, hydroponically
cultivated jambu is promising, since it achieves better yield and

of ionic concentration in nutrient solution on growth, productivity
and gas exchange of jambu. The experimental design was completely

consisted of variations of ionic concentration using the nutrient
solution proposed by Hoagland & Arnon (25, 50, 75, 100 and 125%).

         
photosynthesis, stomatal conductance, transpiration, internal CO2
concentration, Ci/Ca
      
variables, except the stem diameter, the internal CO2 concentration
and the Ci/Ca
grew linearly with maximum values (37.8 units plant-1 and 1650.8
cm2 plant-1, respectively) obtained in ionic concentration of 125%.
Maximum responses were observed for shoot fresh and dry mass (63.9
and 6.9 g plant-1), root fresh and dry mass (16.7 and 2.0 g plant-1)
-1), respectively,
at ionic concentration of 125%. Liquid photosynthesis, stomatal
conductance, transpiration and instant carboxylation efficiency
achieved maximum responses of 17.9 µmol CO2 m-2 s-1, 0.3 mol H2O
m-2 s-1, 6.3 mmol m-2 s-1 and 0.06 with estimated concentrations of 84,
70, 80 and 83% of ionic strength, respectively. Thus, we concluded
that the ionic concentration of 125% is indicated to obtain a greater
biomass accumulation.
Keywords: Acmella oleracea, ionic concentration, fresh and dry
mass.
RESUMO
Respostas produtivas e fisiológicas do jambu (Acmella
oleracea) sob concentrações de nutrientes na solução nutritiva
Nos últimos anos o jambu tem apresentado crescente valorização
e popularidade devido ao seu sabor e paladar marcantes. Assim, o
cultivo hidropônico da espécie torna-se promissor, uma vez que
alcança melhor rendimento e qualidade de produção. Objetivou-se
com esse estudo avaliar o efeito da concentração iônica em solução
nutritiva no crescimento, produtividade e trocas gasosas do jambu. O
experimento foi conduzido no delineamento inteiramente casualizado
com cinco tratamentos e quatro repetições. Os tratamentos foram
constituídos de variações da concentração iônica a partir da solução
nutritiva proposta por Hoagland & Arnon (25, 50, 75, 100 e 125%).
Foram avaliados o comprimento da haste principal, diâmetro do
        
       
estomática, transpiração, concentração interna de CO2, relação Ci/
Ca e eficiência instantânea de carboxilação. As concentrações

diâmetro do caule, a concentração interna de CO2 e a relação Ci/Ca.
     
com máximos valores (37,8 unidades planta-1 e 1.650,8 cm² planta-1,
respectivamente) obtidos na concentração iônica de 125%. Observou-
se máximas respostas para massa fresca e seca da parte aérea (63,9
e 6,9 g planta-1), massa fresca e seca da raiz (16,7 e 2,0 g planta-1)
          -1),
respectivamente, na concentração iônica de 125%. A fotossíntese
        
instantânea de carboxilação obtiveram máximas respostas de 17,9
µmol CO2 m-2 s-1, 0,3 mol H2O m-2 s-1, 6,3 mmol m-2 s-1 e 0,06 com
as concentrações estimadas de 84, 70, 80 e 83% da força iônica,
respectivamente. Assim, conclui-se que para obtenção de maior
acúmulo de biomassa, indica-se a concentração iônica de 125%.
Palavras-chave: Acmella oleracea, concentração iônica, massa
fresca e seca.
Received on June 16, 2020; accepted on December 30, 2020

66 Horticultura Brasileira 39 (1) January - March, 2021

branches. Flowers are arranged in

to achene fruits (Gusmão & Gusmão,
2013). This plant has attracted the
interest of pharmaceutical and cosmetics
industries, due to spilantol, as numerous

analgesic and anesthetic action of this
compound (Sampaio et al., 2020).
However, the production for
commercialization is in small properties
in the municipalities near Belém-PA
(Gusmão & Gusmão, 2013). Besides,
this crop faces several technical problems
which make the productive process
    
productivity and lack of standardization
and plant quality (Sampaio et al., 2018).
Also, seasonality is common, with a

to the festivities in the northern region
of Brazil (Gusmão & Gusmão, 2013).
Thus, aiming quality production in
sufficient amount, jambu cultivation
under hydroponic system can be
promising, since this system promotes

productivity and quality of products
(Portela et al., 2012). Hydroponic
system is a technique for growing plants
without soil as a source of nutrients, so
that these nutrients are available to the
crop through a balanced nutrient solution
(known as standard solution) which
promotes growth and development of
the cultivated plants. So, in this system,
the nutrient solution constitutes one of
the most important aspects in obtaining
high quality vegetable products (Sambo
et al., 2019).
Several formulations of standard
nutrient solutions for leafy vegetables
and fruits can be found in literature
(Furlani, 1997; Furlani et al., 1999).
However, it is worth mentioning that
the formulations, as well as their ionic
concentrations, can vary even within
the plant species, since the absorption
of nutrients varies with the cultivar, the
developmental stage, the hydroponic
system and the climatic conditions in
which the crop is submitted (Portela et
al., 2012).
No suggestion for nutrient solution
formulation for jambu crop can be
found in literature, though. In general,
it is emphasized that the formulation
proposed by Hoagland & Arnon (1950)
is considered the common standard
solution in which variations in relation
to macro and micronutrients can be
verified among them (Furlani et al.,
1999; Cometti et al., 2008). Thus,
further studies on nutrient solution
parameters in productive performance
of jambu are necessary.
Considering the nutrient solution,
electrical conductivity (EC) stands out,
since, it provides information on the
nutrient concentration in the nutrient
solution (Sambo et al., 2019). Thus,
     
productivity, quality and physiological
aspects in several crops can be noticed in
literature (Luz et al., 2012; Portela et al.,
2012; Baron et al., 2015). Portela et al.

nutrient solution on growth, productivity
and quality of the strawberry crop
observed that the increase of EC favored
the growth and production of plants,
as well as increased total soluble solid
contents, anthocyanins, L-ascorbic acid
and total phenols in fruits. In a study,
carried out by Baron et al. (2015),
on production of Annona muricata
seedlings, the results showed that EC
variations of nutrient solution promoted

biomass accumulation.
Given the above, and due to a
small number of studies on jambu
performance under hydroponic system,

ionic concentrations, using the nutrient
solution proposed by Hoagland &
Arnon, (1950) on growth, productivity
and gas exchange of jambu plants,
    
which promotes higher yield.
MATERIAL AND METHODS
The experiment was conducted
in a greenhouse from September 1
to December 21, 2019, at Federal
Rural University of Amazon (UFRA),
located in the municipality of Belém-PA
(1°28’S, 48°30’W, 9 m altitude).
According to Köppen, the climate
is ‘Afi’, 26ºC average temperature
(Alvares et al., 2013).
The experiment was carried out in
a completely randomized design with

treatments consisted of variations of
ionic concentration, using Hoagland
& Arnon’s nutrient solution (1950),
showing the following concentration
(macronutrients in mmol L-1 and
micronutrients in µmol L-1): 15.0 N;
1.0 P; 6.0 K; 5.0 Ca; 2.0 Mg; 2.0 S;
90.0 Fe; 46.3 B; 18.30 Cl; 9.10 Mn;
0.8 Zn; 0.3 Cu and 0.1 Mo. Based
on this standard solution, we used
ionic concentrations (25%, 50%, 75%,
100% and 125%), and the electrical
conductivity was 0.7, 1.3, 2.0, 2.8 and
3.3 dS m-1, respectively. For standard
solution composition, we used pure
reagents for analysis, being the nutrient
sources: NH4H2PO4, KNO3, Ca(NO3)2,
MgSO4, H3BO3, CuSO4.5H2O, FeCl3 +
Na2.EDTA, MnSO4.H2O, H2MoO4.H2O
and ZnSO4.7H2O.
Plants were grown under substrate
system using sterilized ground silica as
a substrate. The authors used 2 L plastic
     
with aluminum foil in order to minimize
the sunlight incidence (increase in
solution temperature), also avoiding
the proliferation of algae inside these
containers. The collecting containers
of nutrient solution were painted with
aluminum metallic paint. Each pot
containing one jambu plant represented
one experimental unit.
The solution was supplied manually
in the pots, with daily frequency being
placed in the morning and drained in the
late afternoon. Whenever necessary, the
water, lost through evapotranspiration,
was replaced with distilled water. The
solution was renewed weekly, and
pH was checked daily with the aid of
a portable peagameter (HANNA®)
and, when necessary, correction was
performed, using NaOH solution or
citric acid (C6H8O7) 1N, keeping it
within the range from 5.5 to 6.5.
Seedlings were produced in
expanded polystyrene trays of 128

Afterwards, seeds were sown (the
achenes) at a density of six seeds per
cell. After germination, trays were
transferred to benches, being kept under
subsurface fertigation system, using
IMG Sampaio et al.

67
Horticultura Brasileira 39 (1) January - March, 2021
Hoagland & Arnon (1950) formulation
at an ionic concentration of 25%. Seven
days after germination, seedlings were
thinned, and just one seedling per cell
was kept. Seedlings were transplanted
at 21 days after germination. Harvest
was done at 56 days after germination.
Before harvesting, between 9 and
11 am, the authors analyzed the gas
exchanges in the second pair of leaves of
the main stem tip of the plants with the aid
of a infrared gas analyzer (IRGA), model
LI-6400XT (LI-COR, Linconl, NE). The
physiological variables evaluated were:
a) CO2 concentration in the substomatic
chamber (Ci, µmol mol-1); b) stomatal
conductance (gs, mol H2O m-2 s-1); c)
liquid photosynthesis (A, µmol CO2 m-2
s-1); d) ratio between the concentration
of CO2 in the substomatic chamber
and the concentration of CO2 in the
environment (Ci/Ca); e) transpiration
(E, mmol m-2 s-1); and, f) carboxylation
efficiency (A/Ci), obtained from the
ratio between liquid photosynthesis and
CO concentration in the substomatic
chamber.
After harvest, the following traits
were evaluated: a) main stem length
(cm), determined with the aid of a
graduated scale; b) stalk diameter,
measured with the aid of a digital
caliper; c) shoot fresh and dry mass
(g plant-1); d) root fresh and dry mass
(g plant-1    
dry mass (g plant-1); f) number of
inflorescence (unit plant-1), through
simple counting; and g) leaf area (cm2
plant-1), determined with the aid of an
area integrating device, LICOR® model
LI-3100.
Fresh and dry masses were
determined after separating each part,
and being weighed using a precision
scale (0.001 g). In order to determine
dry mass, the samples of each part were
kept in paper bags and taken to an oven,
temperature 65ºC for 72 hours until
reaching constant weight.
The results obtained in this study
were submitted to variance analysis and,
   
was carried out. Then, the models
      
The model was chosen based on the
significance showed and superior
  2) (>0.7).
To analyze the data obtained in the
experiment, we used statistic software
Sisvar version 5.6 (Ferreira, 2011).
RESULTS AND DISCUSSION
Ionic concentrations of nutrient

and gas exchanges; the concentrations

CO2 concentration and Ci/Ca ratio,
though.
An increase of nutrient solution

increases in stem diameter, which varied
from 5.0 to 5.4 mm, considering the
smallest (25%) and the greatest (125%)
tested ionic concentrations, respectively
(Figure 1A). Similarly, in lettuce plants
(Lactuca sativa) variety Romana grown
under hydroponics, Cunha-Chiamolera
et al
ionic concentration of nutrient solution
  
plant.
For jambu, the authors observed
that the stem diameter is a trait which is

the nutrient solution, since both in ionic
concentration of 25% (5.0 mm) and of
125% (5.4 mm) no evidence for growth
trend related to this variable was noticed
(Figure 1A). Besides, the fact that jambu
is a rustic plant should be considered
(Gusmão & Gusmão, 2013), since it can
explain the ability to tolerate extreme
variations of nutrient solutions tested
in this study. The authors also highlight
that even in low concentration of
nutrients, no characteristic symptoms of

In relation to main stem length,
the authors observed that an increase
of the ionic concentration promoted
positive responses up to a certain
concentration, which was explained
by a quadratic model (Figure 1B).
The maximum estimated growth was
26.7 cm at a concentration of 90.2%;
from this concentration, the authors
noticed a decrease in this variable,
which can be explained by a possible
nutritional disorder, due to a high
concentration of salts in the solution,
which resulted in plant morphological
changes (Fontes, 2016). For cucumber
crop (Cucumis sativus), Diniz et al.
(2015)
nutrient proportions (12,5, 17, 25, 50
and 100%) on nutrient solution proposed
by Furlani et al. (1999), observed
higher plants grown in more diluted
solutions, where they also verified
that, as the concentration of nutrients
in the solution increased, plant length
decreased. According to Fontes (2016),
excess of nutrients can cause changes
in cellular and biochemical level of
the plants, which results in changes in

plant organs.
For number of produced

observed positive linear response
in relation to an increase of ionic
concentration, production of 37.8
inflorescences plant-1 at the highest
concentration (125%), corresponding
to an increase of approximately 165%
in relation to the smallest tested
concentration (25%). For this crop,
Rodrigues et al. (2014) observed good
   
in relation to nutrient availability in the
soil, also being represented by a positive

the availability of nutrients for jambu

Similarly to what was observed
for inflorescence number, ionic
concentrations increased linearly for
leaf area, showing leaf expansion
of 1650.8 cm2 plant-1 at the highest
ionic concentration (125%). Andrade

concentration on lettuce cultivars under
hydroponic NFT system, also observed
an increase in leaf area of plants as
the concentration of the solution was
increased, which was represented by
a positive linear function. Silva et al.
(2019) observed that an increase in ionic
concentration of the solution promoted a
linear increase in leaf area of the lettuce.
We noticed that the production of
leaves and inflorescences of jambu
under hydroponics system is responsive
to an increased nutrient availability in
the nutrient solution due to its linear
responses, showing that the plant can
also express higher responses when
using higher ionic concentrations. Thus,
concerning productivity, these results
are interesting for the crop, since both
Productive and physiological responses of jambu (Acmella oleracea) under nutrient concentrations in nutrient solution

68 Horticultura Brasileira 39 (1) January - March, 2021

commercialized (Sampaio et al., 2018).
Both shoot dry and fresh mass
(Figures 2A and 2B) increased
proportionally to the increase of ionic
concentration of the nutrient solution,
being higher responses observed in
plants grown in a solution at 125%,
63.9 and 6.9 g plant-1, respectively,
representing an increase of 184%
for fresh mass and 83% for dry mass
comparing with values obtained in ionic
concentration at 25% (22.5 and 3.8 g
plant-1, respectively).
Positive effect on production
considering an increase of ionic
concentration in hydroponics system
had already been demonstrated for
several vegetable species (Cometti
et al., 2008; Genuncio et al., 2012;
Portela et al., 2012). Luz et al. (2012),
   
concentrations (50, 75, 100 and 125%)
of the formulation recommended by
Furlani et al. (1999), observed an
increase in shoot dry and fresh mass
accumulation in parsley (Petroselinum
crispum) and coriander (Coriandrum
sativum). Evaluating productive
responses of lettuce cultivars under
hydroponics system under different
ionic concentrations (50, 75 and 100%),
Genuncio et al. (2012) observed a

increase, being the highest response
achieved at 100% of ionic strength.
Based on these results, studies
     
formulations and their concentrations
on vegetative and reproductive stages
for each species show high relevance.
Thus, using these studies, it is possible

periodic nutrient replacement, establish
nutritional requirements for each
species, as well as reduce the nutrient
concentration in the solution without
yield loss, thus making it possible to
reduce production costs in order to
   
crops (Cometti et al., 2008).
For root fresh and dry mass (Figures
2C and 2D), the authors noticed that an
increase in concentration promoted linear
increases, and the maximum responses
(16.7 and 2.0 g plant-1, respectively)
at 125% concentration, corresponding
to increases of 242.5 and 71.4%,
respectively, when compared with
values obtained at 25% concentration
(4.9 and 1.2 g plant-1). For jambu,
despite the increase in salinity due to the
increase of the ionic concentration of the
nutrient solution, the crop did not show
a reduction in biomass productivity and/
or characteristic symptoms of plants
under salt stress (Negrão et al., 2017).
Similarly, for lettuce crop, Cometti et
al     
root dry mass accumulation as the ionic
concentration of Furlani (1997) nutrient
solution increased, observing that more
diluted solutions obtained less dry
mass accumulations than concentrated
solutions.
In relation to jambu reproductive
    


concentration, being represented by
increasing linear functions (Figure 2E
and 2F), the ionic concentration at 125%
stood out, showing the highest responses
observed in this study (11.0 and 1.8
g plant-1, respectively). Phenological


fruiting the periods of greatest demand
    
fruits represent drain organs with high
demand for photoassimilates to reach
their maturation (Marschner, 2012; Taiz
et al., 2017). This behavior can explain

at a concentration of 125%, since in
this concentration larger availability of
nutrients for growth and development of

with other tested concentration.
Therefore, the electrical conductivity
adjustment (ionic concentration) for
hydroponics cultivation of jambu is a
central parameter for obtaining greater
yields both for fresh mass of shoot and

in this study justify EC adjustments in
other commercial standard solutions
used in vegetable production under
hydroponic systems (Furlani et al.,
1999), based on EC around 3.3 dS m-1,
since this value corresponds to 125%
ionic strength of Hoagland & Arnon
standard solution (1950). In general, it
is important to highlight that the nutrient
solutions of current standards nutritional
Figure 1.           
and leaf area (LA) of jambu plants in relation to the variation in ionic concentration in the

Belém, UFRA, 2020.
IMG Sampaio et al.

69
Horticultura Brasileira 39 (1) January - March, 2021
solutions have as a common ancestor
the solution proposed by Hoagland &
Arnon, (1950), with slight variations in
macro and micronutrient levels between
them (Cometti et al., 2008; Furlani et al.,
1999), thus making the adjustment for
other formulations interesting.
 
variations of ionic concentration in
nutrient solution, as observed for growth
and production, except of Ci and Ci/
Ca ratio which obtained averages of
283.4 µmol mol-1 and 0.73, respectively
(Figure 3).
For A, gs, E and A/Ci, the authors
observed quadratic effects of ionic
concentration in nutrient solution.
Thus, an increase of ionic concentration
promoted positive responses for these
traits up to reaching maximum value of
84, 70, 80 and 83%, respectively.
Thus, the authors observed that as the
photosynthetic rate increased, a similar
increase in stomatal conductance, which
is related to stomatal opening for CO2
entry and transpiration was noticed,
suggesting that a reduction in both gs
and E is associated with a decrease in
A. This is because, although a decrease
in the opening of the stomatal pore was
    Ci and in Ci/
Ca ratio were noticed, which indicates
that the reductions observed for liquid
photosynthesis from the estimated
concentration of 84% of the ionic
concentration are not of stomatal order,
but due to a biochemical limitation of
the process. So, even with the stomatal
closure, the photosynthetic machinery in
the chloroplast not being compromised,
CO2 will continue to be fixed, thus
promoting a reduction in the amount of
internal CO2 (Lemos Neto et al., 2020).


of Ci (Figure 3D), as well as Ci/Ca ratio
were observed (Figure 3E).
In addition, even with CO2

of carboxylation from 83% ionic strength
could be noticed (Figure 3F), indicating
that no CO2 assimilation for synthesis
of organic compounds was observed.
This fact further reinforces the possible
biochemical limitation throughout the
photosynthesis process. According to
Marschner (2012), the increase in EC of
the nutrient solution can cause changes
of the photosynthetic electron transport
chain and/or the enzyme CO2
system, with negative effects on the
photosynthetic rate (Baron et al., 2015).
Andrade (2019), evaluating
physiological responses of lettuce
cultivars in hydroponics system under

reductions in A, gs, E and A/Ci in
more concentrated solutions, being
represented by quadratic functions. We
highlight that, as well as in the present
study, the mentioned author did not
observe significant effect of Ci and
Ci/Ca ratio with an increase of ionic
concentration of the solution. Thus,
the loss of photosynthetic efficiency
observed in this study was also related
to possible non-stomatic limitations,
      
absorption of nutrients such as Ca and
Mg, which had their levels reduced
as the electrical conductivity of the
solution increased
Baron et al. (2015), evaluating the
influence of nutrient availability of
Hoagland & Arnon nutrient solution
2 (1950) on gas exchanges, nutritional
state and leaf biomass production of star
fruit (Annona emarginata) seedlings,
observed that the plants grown under
100% ionic concentration showed lower
contents of Mg, Ca and S in their leaves
in relation to other concentrations.
Besides, these authors also observed
reduction of liquid photosynthesis and

ionic concentration, which indicates
that the changes in mineral composition
Figure 2. Shoot fresh mass (FMA), shoot dry mass (DMA), root fresh mass (FMR), root

of jambu plants in relation to the variation of ionic concentration in the nutrient solution.

Productive and physiological responses of jambu (Acmella oleracea) under nutrient concentrations in nutrient solution

70 Horticultura Brasileira 39 (1) January - March, 2021
   
the crop.
Growth and productive responses
observed in jambu as the concentration
of nutrients in the nutrient solution
increased may be related to the increase
in physiological traits. However, we
highlight that reductions in A (Figure
3A) and A/Ci (Figure 3F) in higher
nutrient concentrations were noticed,
which corroborate most of the results

that jambu throughout its vegetative
and reproductive cycle adapted to this
condition of loss of photosynthetic
    
linear increase in growth (Figure 1) and
productivity of the crop was noticed
(Figure 2) with the increase of ionic
concentration in the nutrient solution,
mainly using the concentration of 125%.
Thus, the authors concluded that
ionic concentrations in the nutrient so-

and physiological traits of jambu, con-
sidering that to obtain greater biomass
accumulation, we suggest the ionic
concentration of 125% of Hoagland &
Arnon standard solution (1950), which
corresponds to an electrical conductivity
of 3.3 dS m-1.
ACKNOWLEDGMENTS
The Amazon Foundation for the
Support of Studies and Research
(Fapespa) for granting an academic
doctorate, ICAAF No. 009/2017, to the
  
Improvement Coordination (CAPES) for
granting a mastering scholarship to the
third author (Proc. 88887.572120/2020-
00) and for the publication support given
by CAPES-PGAgro-UFRA.
REFERENCES
ALVARES, CA; STAPE, JL; SENTELHAS, PC;
GONÇALVES, JLM; SPAROVEK, G. 2013.

Meteorologische Zeitschrift, 22: 711–728.
https://doi.org/10.1127/0941-2948/2013/0507
ANDRADE, RR. 2019. Efeito da concentração
da solução nutritiva em cultivares de alface
em sistema hidropônico tipo NFT, em clima
Semiárido. Fortaleza: UFC. 95p. (Ph.D.
Thesis).
BARON, D; FERREIRA, G; BOARO, CSF;
RODRIGUES, JD; AMARO, ACE:
MISCHAN, MM. 2015. The effect of the
ionic strength of nutrient solution on gas
exchange, ionic concentration and leaf biomass
of Annona emarginata (Schltdl.) H. Rainer
variety ‘terra-fria’ seedlings. Journal of Plant
Nutrition. 38: 1944–1960. https://doi.org/10.
1080/01904167.2014.991037
COMETTI, NN; MATIS, GCS; ZONTA, E;
WELLINGTON, M; FERNANDES, MS.
2008. Efeito da concentração da solução
nutritiva no crescimento da alface em cultivo
hidropônico-sistema NFT. Horticultura
Brasileira, 26: 5.
CUNHA-CHIAMOLERA, TPL;
URRESTARAZU, M; CÉCÍLIO FILHO,
AB; MORALES, I. 2017. Agronomic and
economic feasibility of tomato and lettuce
intercropping in a soilless system as a function
of the electrical conductivity of the nutrient
solution. HortScience, 52: 1195-1200. https://
doi.org/10.21273/HORTSCI12170-17
DINIZ, AA; DIAS, NDS; SOUZA, FI; SOUZA,
ACM; MESQUITA, FDO; SOUZA, FI. 2015.
Efeito da solução nutritiva sob o crescimento
e composição mineral em pepino cultivado
em substrato de fibra de coco. Semina:
Ciências Agrárias, 36: 3043. https://doi.
org/10.5433/1679-0359.2015v36n5p3043
FERREIRA, DF. 2011. Sisvar: a computer
statistical analysis system. Ciência
Agrotecnológica, 35: 1039–1042.
FONTES, PCR. 2016. Nutrição mineral de
plantas: anamnese e diagnóstico. Viçosa:
UFV. 315p.
FURLANI, PR. 1997. Instruções para o cultivo
de hortaliças de folhas pela técnica de
hidroponia-NFT. Campinas: Instituto
Agronômico. 30.
FURLANI, PR; SILVEIRA, LCP; BOLONHEZI,
D; FAQUIN, V. 1999. Cultivo hidropônico
de plantas. Campinas: Instituto Agronômico.
180p. 50.
GENUNCIO, CG; GOMES, M; FERRARI,
AC; MAJEROWICZ, N; ZONTA, E. 2012.
    
concentrations and flow rates of nutrient
solution. Horticultura Brasileira, 30: 526-530.
GUSMÃO, MTA; GUSMÃO, SAL. 2013.
Jambu da Amazônia: Acmella oleracea, (L.)
RK Jansen: Caractecrísticas gerais, cultivo
Figure 3. Liquid photosynthesis (A), stomatic conductance (gs), transpiration (E), internal



IMG Sampaio et al.

71
Horticultura Brasileira 39 (1) January - March, 2021
convencional, orgânico e hidropônico. In:
GUSMÃO, MTA; GUSMÃO, SAL (eds). 1st
ed. Edufra.
HOAGLAND, DR; ARNON, DI 1950. The water-
culture method for growing plants without soil.
Circular. California Agricultural Experiment
Station, 347: 32.
HOMMA, AKO; SANCHES, RS; MENEZES,
JEAA; GUSMÃO, SAL. 2011. Etnocultivo do
jambu para abastecimento da cidade de Belém,
estado do Pará. Amazônia: Ci. & Desenv, 6: 17.
LEMOS NETO, HS; GUIMARÃES, MA;
SAMPAIO, IMG; RABELO, JS; VIANA,
CS; MESQUITA, RO. 2020. Can silicon (Si)

quality of lettuce? Australian Journal of Crop
Science 14: 71–77. https://doi.org/10.21475/
ajcs.20.14.01.p1848
LUZ, JMQ; ANDRADE, LV; DIAS, FF; SILVA,
MAD; HABER, LL; OLIVEIRA, RC. 2012.
Produção hidropônica de coentro e salsa
crespa sob concentrações de solução nutritiva

Bioscience Journal, 28: 589-597.
MARSCHNER, P. 2012. Marschner’s mineral
nutrition of higher plants. Elsevier. https://doi.
org/10.1016/C2009-0-63043-9
NEGRÃO, S; SCHMÖCKEL, SM; TESTER, M.
2017. Evaluating physiological responses of
plants to salinity stress. Annals of Botany, 119:
1–11. https://doi.org/10.1093/aob/mcw191
PORTELA, IP; PEIL, RMN; ROMBALDI,
CV. 2012. Efeito da concentração de
nutrientes no crescimento, produtividade
e qualidade de morangos em hidroponia.
Horticultura Brasileira 30: 266-273. https://
doi.org/10.1590/S0102-05362012000200014
RODRIGUES, DS; CAMARGO, MS; NOMURA,
ES; GARCIA, VA; CORREA, JN; VIDAL,
TCM. 2014. Influencia da adubação com
nitrogênio e fósforo na produção de jambu,
Acmella oleracea (L). In: JANSEN RK (ed).
Revista Brasileira de Plantas Medicinais (Vol.
16, Issue 1).
SAMBO, P; NICOLETTO, C; GIRO, A; PII, Y;
VALENTINUZZI, F; MIMMO, T; LUGLI,
P; ORZES, G; MAZZETTO, F; ASTOLFI, S;
TERZANO, R; CESCO, S. 2019. Hydroponic
solutions for soilless production systems:
Issues and opportunities in a smart agriculture
perspective. Frontiers in Plant Science 10.
https://doi.org/10.3389/fpls.2019.00923
SAMPAIO, IMG; GUIMARÃES, MA; LEMOS
NETO, HS; MAIA, CL; VIANA, CS;
GUSMÃO, SAL. 2018. Pode o uso de mudas
agrupadas e a maior densidade de plantio
aumentar a produtividade de jambu? Revista
de Ciências Agrárias 61: 1-8. https://doi.
org/10.22491/rca.2018.2906
SAMPAIO, IMG; GUIMARÃES, MA;
LEMOS NETO, HS; MAIA, CL; VIANA,
CS; GUSMÃO, SAL. 2019. Recipientes e
densidades de semeadura combinadas com
o tempo na produção de mudas de jambu.
Revista de Ciências Agrárias, 62. https://doi.
org/10.22491/rca.2019.2996
SAMPAIO, IMG; SILVA JÚNIOR, ML;
CHAGAS, EDS; BITTENCOURT, RFPM;
COSTA, VCN; SOUZA, DL; SANTOS, WAS;
TEXEIRA, BJB. 2020. Evaluation of the non-
    
nitrogen content in jambu plants grown in
hydroponic system. Journal of Agricultural
Studies 8: 466. https://doi.org/10.5296/jas.
v8i2.16380
SILVA, PF; MATOS, RM; BONOU, SM;
SOBRINHO, TG; BORGES, VE; DANTAS
NETO, J; MELLO JÚNIOR, AP. 2019.
Yield of the hydroponic lettuce under levels
of salinity of the nutrition solution. African
Journal of Agricultural Research, 14: 686-693.
https://doi.org/ 10.5897/AJAR2018.13782
TAIZ, L; ZEIGER, E; MOLLER, IM; MURPHY,
A. 2017. Fisiologia e desenvolvimento vegetal.
In: TAIZ, L; ZEIGER, E; MOLLER, IM;
MURPHY, A (eds). 6th ed. Artmed Editora
Productive and physiological responses of jambu (Acmella oleracea) under nutrient concentrations in nutrient solution