© The Authors, 2025, Published by the Universidad del Zulia*Corresponding author:jenaro.reyes@correo.buap.mx
Keywords:
Cationic ratio
Mineral balance
Nutrient uptake
Greenhouse production
Inuence of the K
+
/Ca
2+
+Mg
2+
ratio in the yield of zucchini (Cucurbita pepo L.)
Influencia de la relación K
+
/Ca
2+
+Mg
2+
en el rendimiento de calabacita (Cucurbita pepo L.)
Influência da relação K
+
/Ca
2+
+Mg
2+
na produtividade de abobrinha (Cucurbita pepo L.)
Rolando Rueda-Luna
1
Jenaro Reyes-Matamoros
1*
Miriam Romero-Hernández
1
Raymundo Hernández-Loma
2
Abel Cruz-Montalvo
1
Rev. Fac. Agron. (LUZ). 2025, 42(1): e244215
ISSN 2477-9407
DOI: https://doi.org/10.47280/RevFacAgron(LUZ).v42.n1.XV
Crop production
Associate editor: Dr. Jorge Vilchez-Perozo
University of Zulia, Faculty of Agronomy
Bolivarian Republic of Venezuela
1
Centro de Investigación en Ciencias Agrícolas. Benemérita
Universidad Autónoma de Puebla (BUAP). Av. 14 Sur 6301,
CU, Col. San Manuel, C.P. 72570, Puebla, Pue., México
2
Facultad de Ingeniería Agroindustrial, Complejo Regional
Centro, Sede Tecamachalco, Benemérita Universidad
Autónoma de Puebla (BUAP). Km 7.5 carretera Cañada
Morelos, El Salado Tecamachalco, Pue., México
Received: 19-11-2024
Accepted: 29-01-2025
Published: 24-02-2025
Abstract
Zucchini (Cucurbita pepo L.) is a widely cultivated vegetable
that plays a signicant role in global food production. Its yield
and nutritional composition are inuenced by various agronomic
factors, including the availability and balance of essential nutrients.
Among these, the cationic ratio of potassium (K
+
), calcium
(Ca
2+
), and magnesium (Mg
2+
) in the nutrient solution is critical
for plant growth and productivity due to their interactive eects
on absorption and transport. The objective of this study was to
evaluate the impact of dierent K
+
/Ca
2+
+Mg
2+
ratios on the yield
and mineral composition of zucchini leaves. The experiment was
conducted under greenhouse conditions using a factorial design
with two commercial varieties (Zuchinni Gray and Ambrosia) and
ve nutrient solutions with dierent cation ratios (K
+
/Ca
2+
+Mg
2+
;
0.2, 0.6, 1.0, 1.4, and 1.8). Plants were grown in polyethylene
containers lled with red tezontle substrate. The results showed that
Ambrosia exhibited a higher total yield compared to Zuchinni Gray.
The K
+
/Ca
2+
+Mg
2+
ratios of 1.4 and 1.8 signicantly increased total
production, while the ratio of 1.4 enhanced calcium absorption.
However, no signicant dierences were observed in potassium
and magnesium content in the leaves. These ndings highlight
the importance of optimizing the cationic balance in the nutrient
solution to improve zucchini productivity and mineral composition.
This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.
Rev. Fac. Agron. (LUZ). 2025, 42(1): e254215 January-March. ISSN 2477-9409.
2-5 |
Resumen
La calabacita (Cucurbita pepo L.) es una hortaliza ampliamente
cultivada que desempeña un papel signicativo en la producción
mundial de alimentos. Su rendimiento y composición nutricional
están inuenciados por diversos factores agronómicos, incluida la
disponibilidad y el equilibrio de nutrientes esenciales. Entre estos,
la relación catiónica de potasio (K
+
), calcio (Ca
2+
) y magnesio
(Mg
2+
) en la solución nutritiva es crítica para el crecimiento y la
productividad de la planta debido a sus efectos interactivos en la
absorción y el transporte. El objetivo de este estudio fue evaluar el
impacto de diferentes relaciones K
+
/Ca
2+
+Mg
2+
sobre el rendimiento
y la composición mineral de las hojas de calabacita. El experimento
se llevó a cabo en condiciones de invernadero utilizando un diseño
factorial con dos variedades comerciales (Zuchinni Gray y Ambrosia)
y cinco soluciones nutritivas con diferentes relaciones catiónicas (K
+
/
Ca
2+
+Mg
2+
; 0.2, 0.6, 1.0, 1.4 y 1.8). Las plantas se cultivaron en
contenedores de polietileno llenos con sustrato de tezontle rojo. Los
resultados mostraron que la variedad Ambrosia presentó un mayor
rendimiento total en comparación con Zuchinni Gray. Las relaciones
K
+
/Ca
2+
+Mg
2+
de 1.4 y 1.8 incrementaron signicativamente la
producción total, mientras que la relación de 1.4 favoreció la absorción
de calcio. Sin embargo, no se observaron diferencias signicativas
en el contenido de potasio y magnesio en las hojas. Estos hallazgos
resaltan la importancia de optimizar el equilibrio catiónico en la
solución nutritiva para mejorar la productividad y la composición
mineral de la calabacita.
Palabras clave: relación catiónica, balance mineral, absorción de
nutrientes, producción en invernadero.
Resumo
A abobrinha (Cucurbita pepo L.) é uma hortaliça amplamente
cultivada que desempenha um papel signicativo na produção
mundial de alimentos. Seu rendimento e composição nutricional
são inuenciados por diversos fatores agronômicos, incluindo
a disponibilidade e o equilíbrio de nutrientes essenciais. Entre
esses fatores, a relação catiônica de potássio (K
+
), cálcio (Ca
2+
) e
magnésio (Mg
2+
) na solução nutritiva é crucial para o crescimento
e a produtividade das plantas devido aos seus efeitos interativos
na absorção e no transporte de nutrientes. O objetivo deste estudo
foi avaliar o impacto de diferentes relações K
+
/Ca
2+
+Mg
2+
no
rendimento e na composição mineral das folhas de abobrinha. O
experimento foi conduzido em condições de estufa, utilizando um
delineamento fatorial com duas variedades comerciais (Zuchinni
Gray e Ambrosia) e cinco soluções nutritivas com diferentes relações
catiônicas (K
+
/Ca
2+
+Mg
2+
; 0,2, 0,6, 1,0, 1,4 e 1,8). As plantas foram
cultivadas em recipientes de polietileno preenchidos com substrato
de tezontle vermelho. Os resultados mostraram que a variedade
Ambrosia apresentou maior rendimento total em comparação com a
Zuchinni Gray. As relações K
+
/Ca
2+
+Mg
2+
de 1,4 e 1,8 aumentaram
signicativamente a produção total, enquanto a relação de 1,4
favoreceu a absorção de cálcio. No entanto, não foram observadas
diferenças signicativas nos teores de potássio e magnésio nas folhas.
Esses achados destacam a importância da otimização do equilíbrio
catiônico na solução nutritiva para melhorar a produtividade e a
composição mineral da abobrinha.
Palabras-chave: relação catiônica, equilíbrio mineral, absorção de
nutrientes, produção em estufa.
Introduction
The immature fruits of the zucchini (Cucurbita pepo L.) are
primarily consumed, as a vegetable, in both domestic and export
markets. Over the past decade, the cultivation of this vegetable has
experienced a period of sustained growth in the state of Puebla,
ranking rst among vegetables utilized for their fruit. The cultivated
area has reached 4,080.36 hectares, with an average yield of 17.44
t.ha
-1
(SIAP, 2023). However, this yield is below the national average
of 21.23 t.ha
-1
(SIAP, 2023). This issue may be attributed to the dearth
of varieties that are tolerant to the particular conditions of the region,
the prevalence of pests and diseases, inadequate plant nutrition, and
other technological requirements (SDR, 2007). Conversely, excessive
application of fertilizers to agricultural soils can result in long-term
salinization and the loss of benecial soil microorganisms, as well
as environmental contamination (Santos-Coello & Ríos-Mesa, 2016).
It is therefore necessary to maximize the utilization of nutrient by
crops through the administration of appropriate doses of fertilizer.
The availability of cations such as potassium (K
+
), calcium (Ca
2+
),
and magnesium (Mg
2+
) in relation to their absorption, transport, and
utilization by plants depends on maintaining a proper balance between
them, which must be achieved for optimal absorption (Cadahía-
López, 2005). As indicated by Havlin et al. (2017) the eciency of
plant absorption of K
+
is inuenced by the presence of Ca
2+
and Mg
2+
,
particularly. Therefore, the relationship between these cations serves
as an indicator of the labile K in the soil, representing the quantity of
potassium that is immediately accessible to crop roots. Furthermore,
the literature mentions that nutrient absorption in C. pepo during the
growing season exhibits a positive linear trend (Rodas-Gaitán et al.,
2012).
In recent years, generated technology has been developed with
the objective of enhancing the eciency and sustainability of
the agricultural production systems, This has been done, with the
intention of reducing costs, increasing protability, ensuring the
provision of safe food, and mitigating the negative environmental
impacts resulting from the excessive use of agrochemicals (Aguilar-
Carpio et al., 2022). In this regard, a valuable approach is to ascertain
the nutrient demand of cultivated species, considering both nutrient
absorption eciency and the utilization of the fertilizer source, and
subsequently devise an eective fertilization plan (Estrada-Herrera
et al., 2017). It is beyond question that the study of crop nutrition
plays a fundamental role (Alcántar-González & Trejo–Téllez, 2010).
Accordingly, the objective of this study was to evaluate the impact of
the K
+
/Ca
2+
+Mg
2+
ratio on the yield and nutritional composition of
zucchini leaves.
Materials and methods
The experiment was conducted at the facilities of the Agricultural
Sciences Research Center at the Benemérita Universidad Autónoma
de Puebla, Puebla, Mexico. The center is located at 19° 14’ north
latitude and 98° 18’ west longitude, at an altitude of 2150 meters
above sea level (INEGI, 2014). The crop was cultivated in a tunnel-
type greenhouse with milky white plastic cover and 25 % shade
netting. On January 18, 2023, the seedlings were transplanted at the
two true leaf stage into polyethylene containers measuring 30 x 40 cm
and lled with red tezontle, a substrate comprising particles less
than 16 mm in size. The planting layout was arranged in double rows
with a distance of 1.5 meters between rows and a distance of 0.25
This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.
Rueda-Luna et al. Rev. Fac. Agron. (LUZ). 2025, 42(1): e254215
3-5 |
meters between plants, resulting in a population density of 2.6 plants
per square meter. Irrigation was conducted manually, with volume
applied depended on the phenological stage, while maintaining a
drainage volume of 30 % starting from the time of transplantation
onwards. The irrigation sheet was applied as follows: 300 mL per
plant during the vegetative stage, 600 mL during owering, 1000 mL
during fruiting, and 1200 mL during the harvest period.
Two dierent commercial varieties of zucchini were utilized in
this study. The varieties of zucchini utilized in the study were Zuchinni
Gray and Ambrosia. Five nutrient solutions with varying cation ratios
(K
+
/Ca
2+
+Mg
2+
; 0.2, 0.6, 1.0, 1.4, and 1.8) were employed. The
experiment was designed in a 2 x 5 factorial arrangement, with two
varieties of zucchini and ve proposed nutrient solutions, replicated
three times, for a total of 30 experimental units (R.U.). The nal
nutrient solutions for potassium were as follows: The concentrations
of potassium, calcium, and magnesium were 6.28, 6.01, 7.5, 7.25,
and 9.0, 6.7, 3.21, 2.35, and 1.01, 1.35, respectively. The respective
concentrations of potassium, calcium, and magnesium in meq.L
-1
were 5.7, 1.55, 1.22, 1.41, and 1.1 for each ratio of K
+
/Ca
2+
+Mg
2+
.
The remaining elements were maintained at a constant level in all
cases, with the pH of the various nutrient solutions adjusted to a value
of 6.5.
The harvest index and frequency were dened based on
commercial maturity criteria commonly used for zucchini harvesting
(Maroto-Borrego, 2002). A total of 10 harvest dates were recorded
throughout the production cycle. The total production, accumulated
over 10 harvest dates, dry and fresh leaf weights, and the content
of K, Ca, and Mg were evaluated in mature leaves collected at the
fruiting stage. The corresponding readings were obtained using an
atomic absorption spectrophotometer (Varian brand, model SpectrAA
55B®). The results were subjected to analysis of variance (ANOVA),
and mean comparisons were made using the Tukey test, which was
performed using the statistical software package Statgraphics version
4.1 Centurion.
Results and discussion
The results show a clear varietal eect, with Ambrosia displaying
superior total production, fruit count, and fruit length in comparison
to Zuchinni Gray, exhibiting statistically signicant dierences
(p≤0.05) (table 1).
Table 1. Productive parameters of Zucchini.
Total production
(g/R.U.)
Number of fruits
(R.U.)
Average weight
(g/R.U.)
Fruit diameter
(cm)
Fruit length
(cm)
Variety
Ambrosia 3237.79 ± 400.99 a 20.53 ± 2.16 A 155.3 ± 5.53 b 4.61 ± 0.19 ns 14.77 ± 0.51 a
Zuchinni Gray 2541.72 ± 352.99 b 14.67 ± 2.36 B 169.39 ± 13.09 a 4.73 ± 0.36 ns 13.71 ± 0.42 b
K
+
/Ca
+2
+Mg
+2
Ratio
0.2 1269.33 ± 332.28 B 10.67± 2.63 C 116.0 ± 2.68 C 3.92 ± 0.49 B 12.83 ± 0.54 B
0.6 2797.2 ± 282.17 AB 12.67 ± 1.91 BC 212.78 ± 20.3 A 5.08 ± 0.63 AB 14.62 ± 0.87 AB
1.0 2652.07 ± 506.71 AB 16.67 ± 2.99 ABC 158.15 ± 6.93 B 5.53 ± 0.29 A 15.88 ± 0.41 A
1.4 3467.31 ± 443.74 A 22.67 ± 3.68 AB 156.85 ± 5.43 B 4.18 ± 0.21 AB 13.48 ± 0.46 AB
1.8 4262.87± 702.29 A 25.33 ± 3.91 A 167.96 ± 3.41 B 4.65 ± 0.18 AB 14.40 ± 0.9 AB
Interaction Variety x Ratio ** ** ** ** *
Dierent letters (uppercase/lowercase) in the same column indicate statistically signicant dierences at 99 % and 95 % respectively according to the Tukey test. Not signicant (ns), signicance
level at 0.05 (*), 0.01 (**). R.U.: Repetition unit (3 plants).
This nding aligns with Purquerio et al. (2019), who observed
signicant dierences in growth and yield among zucchini cultivars,
with varying nutrient management resulting in substantial dierences
in biomass accumulation and fruit yield. However, the highest
mean fruit weight was observed for Zuchinni Gray with statistically
signicant dierences (p≤0.05), and were while no dierences were
noted in fruit diameter. Regarding the K
+
/Ca
2+
+Mg
2+
ratio, plants that
received the nutrient solution with a ratio of 1.4 and 1.8 exhibited
enhanced total production and a greater number of fruits with
statistically signicant dierences (p≤0.01). These ndings suggest
a correlation between elevated K
+
/Ca
2+
+Mg
2+
ratios and enhanced
productivity. Moreover, the interaction results demonstrated that the
Ambrosia variety exhibited a greater productivity advantage, both in
terms of total production and fruit count, with a K
+
/Ca
2+
+Mg
2+
ratio
of 1.8. Conversely, the Zuchinni Gray variety demonstrated superior
performance with a ratio of 1.4 in terms of total production. However,
regarding fruit count, the 1.8 ratio exhibited the highest value (Table
2). Seth et al. (2018) emphasized that the K
+
/Ca
2+
+Mg
2+
ratio plays a
crucial role in the eciency of potassium uptake, inuencing overall
plant growth and yield, which supports our ndings of a stronger
productivity response in plants receiving nutrient solutions with
higher K
+
/Ca
2+
+Mg
2+
ratios. Similarly, Neocleous & Savvas (2018)
found that increasing calcium concentrations can aect the uptake of
other macronutrients and overall plant growth, further highlighting
the importance of optimizing nutrient ratios in promoting healthy,
productive crops.
In terms of fresh and dry leaf weight (Table 3), the results indicate
the absence of statistically signicant dierences between the
varieties. Regarding the K
+
/Ca
2+
+Mg
2+
ratio, higher dry weight was
recorded with a K
+
/Ca
2+
+Mg
2+
ratio of 1.0 with statistically signicant
dierences (p≤0.01). However, the dierent K
+
/Ca
2+
+Mg
2+
ratios in
the nutrient solution did not aect the fresh leaf weight of the plants,
as no clear dierences were observed between the treatments.
Table 4 presents the results of the foliar analysis conducted during
the fruiting stage. At the varietal level, no dierences were observed
in the mineral elements of potassium and magnesium. However,
a higher concentration of calcium (4377.0 ppm) was observed
in Ambrosia compared to Zuchinni Gray (4156.33 ppm), with
statistically signicant dierences (p≤0.05). Regarding the dierent
K
+
/Ca
2+
+Mg
2+
ratios, no dierences were observed with respect to
potassium and magnesium. However, the plants that received the
nutrient solution with a K
+
/Ca
2+
+Mg
2+
ratio of 1.0 and 1.4 exhibited the
highest calcium contents (4550.0 ppm in both cases), with signicant
dierences (p≤0.01). No statistically signicant dierences were
observed in the variety x K
+
/Ca
2+
+Mg
2+
ratio interaction.
This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.
Rev. Fac. Agron. (LUZ). 2025, 42(1): e254215 January-March. ISSN 2477-9409.
4-5 |
Table 2. Interaction of zucchini production parameters.
Variety
K
+
/Ca
+2
+Mg
+2
ratio
Total production
(g/R.U.)
Total number
of fruits
Average
weight
(g/R.U.)
Fruit diameter (cm)
Ambrosia
0.2 1952.0 c 16.0 b 122.0 b 5.0 a
0.6 2471.73 b 14.67 b 170.34 a 4.07 a
1.0 3396.13 b 21.33 b 157.3 b 5.23 a
1.4 2781.33 b 17.33 b 160.63 b 3.8 a
1.8 5587.73 a 33.33 a 166.25 b 4.96 a
Zuchinni Gray
0.2 586.66 c 5.33 a 110.00 b 2.83 b
0.6 3122.67 b 10.67 a 255.21 a 6.08 a
1.0 1908.0 b 12.0 a 159.0 a 5.83 a
1.4 4153.28 a 28.0 a 153.07 a 2.88 b
1.8 2938.0 b 17.33 b 169.66 a 4.33 a
LSD (p≤0.05) 1433.56 9.17 23.64 1.74
Means with the same letter are equal at signicance level p≤0.05. R.U.: Repetition unit (3 plants)
Table 3. Weight of developed zucchini leaves at fruiting stage.
Fresh weight
(g/R.U.)
Dry weight
(g/R.U.)
Variety
Ambrosia 27.85 ± 1.1 ns 4.18 ± 0.24 ns
Zuchinni Gray 26.18 ± 1.05 ns 3.69 ± 0.28 ns
K
+
/Ca
+2
+Mg
+2
Ratio
0.2 26.06 ± 1.59 ns 3.16 ± 0.3 B
0.6 26.18 ± 1.91 ns 3.33 ± 0.42 B
1.0 30.5 ± 1.33 ns 5.11 ± 0.27 A
1.4 25.67 ± 1.17 ns 3.83 ± 0.28 AB
1.8 26.67 ± 2.12 ns 4.25 ± 0.3 AB
Interaction Variety x Ratio ns ns
Dierent letters in the same column indicate statistically signicant dierences at 99 % according to the Tukey test. Not signicant (ns). R.U.: Repetition unit (3 plants).
Table 4. K
+
/Ca
+2
+Mg
+2
ratio in zucchini leaves.
K
(ppm)
Ca
(ppm)
Mg
(ppm)
Variety
Ambrosia 4095.0 ± 82.39 ns 4377.0 ± 107.19 A 2120.0 ± 89.17 ns
Zuchinni Gray 4185.0 ± 116.77 ns 4156.33 ± 84.75 B 2125.0 ± 112.14 ns
K
+
/Ca
+2
+Mg
+2
Ratio
0.2 4062.5 ± 170.65 ns 4063.33 ± 65.8 B 2150.0 ± 71.22 ns
0.6 4100.0 ± 146.24 ns 4062.5 ± 145.04 B 2112.5 ± 223.18 ns
1.0 4112.5 ± 157.39 ns 4550.0 ± 110.37 A 2212.5 ± 129.66 ns
1.4 4225.0 ± 161.09 ns 4550.00 ± 81.75 A 2050.0 ± 185.12 ns
1.8 4200.0 ± 199.8 ns 4107.5 ± 211.82 B 2087.5 ± 186.13 ns
Interaction Variety x Ratio ns ns ns
Dierent letters in the same column indicate statistically signicant dierences at 99 % according to the Tukey test. Not signicant (ns).
The analysis of the results indicates that the Ambrosia variety
exhibited superior productivity compared to Zuchinni Gray, which
could be attributed to a varietal response. In order to ascertain the
average fruit weight, and in considering of fruit maturity, the reference
values proposed by Maroto-Borrego (2002) were employed. These
values indicate that commercially viable fruits should exhibit a length
of 15-18 cm and a weight of 200-250 g at the time of harvesting.
The K
+
/Ca
2+
+Mg
2+
ratio of 1.4 and 1.8 was observed to increase
total production in both cultivars, indicating a trend towards higher
productivity with higher K
+
/Ca
2+
+Mg
2+
ratios. These results align with
the ndings of Seth et al. (2018), who point out that the availability
and absorption of K
+
are inuenced by the proportion of the competing
cations Ca
2+
and Mg
2+
, and that an optimal K
+
ratio promotes greater
productivity in dierent cropping systems. Additionally, Purquerio et
al. (2019) observed a similar trend in zucchini where higher nutrient
uptake, particularly of potassium, led to improved yields and plant
growth. However, the interaction results indicate that the Ambrosia
variety exhibits greater productivity with a K
+
/Ca
2+
+Mg
2+
ratio of
1.8 (yielding 1.86 kg per plant), while the Zuchinni Gray variety
demonstrates a superior response to a ratio of 1.4 (yielding 0.93 kg per
This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.
Rueda-Luna et al. Rev. Fac. Agron. (LUZ). 2025, 42(1): e254215
5-5 |
plant). These values are below those reported by Moreno-Reséndez et
al. (2019) for the Mona Lisa F1 hybrid, which yielded 3.987 kg per
plant. These discrepancies could be attributed to the diering nutrient
requirements of the cultivars.
The highest dry leaf weight was observed when the K
+
/Ca
2+
+Mg
2+
ratio was 1.0. However, the dierent K
+
/Ca
2+
+Mg
2+
ratios in the
nutrient solution did not aect the dry leaf weight of the plant.
Nevertheless, they could inuence greater calcium assimilation and
a potential increase in average fruit weight. The results suggest that
the optimal K
+
/Ca
2+
+Mg
2+
ratio in plant nutrition may be established
a balance point between production and dry plant weight, situated
between 1.0 and 1.8 (in meq.L
-1
). These values may be considered
as reference indices for zucchini cultivation. Similar results were
reported by Diovisalvi et al. (2021) in a study of dierent soybean crop
nutrition. In a related study, Aguilar-Carpio et al. (2022) observed that
the integration of chemical fertilization with biostimulants, such as
seaweed extracts, resulted in enhanced growth, yield, and protability
in zucchini. These ndings highlight the potential of optimized
nutrient management strategies to enhance crop productivity. In
line with this, Melito et al. (2023) found that applying appropriate
levels of organic-mineral fertilizers increased the growth and yield
of zucchini, supporting the notion that nutrient optimization plays a
signicant role in enhancing zucchini productivity.
The results of the leaf analysis reect a higher concentration
of calcium (4377.0 ppm) in Ambrosia compared to Zuchinni Gray
(4156.33 ppm). Similarly, the highest calcium values were recorded
in plants that received the nutrient solution with a K
+
/Ca
2+
+Mg
2+
ratio
of 1.0 and 1.4, with values of 4550.0 ppm in both cases. The statistical
analysis revealed no signicant dierences in the mineral elements
potassium and magnesium among the cultivars or across the dierent
K
+
/Ca
2+
+Mg
2+
ratios.
The overall, the assimilation of cations K
+
, Ca
2+
and Mg
2+
was
found to be similar between the evaluated cultivars, irrespective of
the harvest date. The absorption of potassium (4225.0 ppm) was
higher following fruit formation with a K
+
/Ca
2+
+Mg
2+
ratio of 1.4,
as potassium is an element that typically inuences fruit coloration,
increasing pigmentation by raising carotenoid content while reducing
chlorophyll content (CPHA, 2004). Furthermore, the absorption of
calcium reached concentrations of 4550.0 ppm, while magnesium
reached 2050.0 ppm. These results are in accordance with the ndings
of Rodas-Gaitán et al. (2012), who observed that in zucchini, calcium
was the primary absorbed element at 7.47, followed by magnesium
at 2.07 and potassium at 1.37 g.plant
-1
. However, the present study
revealed higher potassium concentration was observed. With regard
to calcium, its assimilation also increased during the fruiting stage
with the highest contents observed in the leaves of plants that received
a K
+
/Ca
2+
+Mg
2+
ratio of 1.0 and 1.4. In contrast, plants that received
a K
+
/Ca
2+
+Mg
2+
ratio of 0.2 and 0.6 exhibited the lowest calcium
contents across all evaluated physiological stages, potentially due to
the antagonism relationship between the Ca
2+
ion and K
+
(Villalobos
et al., 2009). This further supports the idea that nutrient balance,
especially between calcium and potassium, plays a key role in
determining plant health and fruit yield (Neocleous & Savvas, 2018).
Seth et al. (2018) similarly found that an optimal balance between
K
+
, Ca
2+
, and Mg
2+
is essential for maximizing nutrient uptake and
minimizing the antagonistic eects between these cations.
Conclusions
It can be concluded that there is a varietal eect, with the
Ambrosia variety demonstrating a higher total production compared
to Zuchinni Gray. The K
+
/Ca
2+
+Mg
2+
ratio signicantly inuenced
the yield and nutritional composition of zucchini, with Ambrosia
showing superior productivity compared to Zuchinni Gray. The K
+
/
Ca
2+
+Mg
2+
ratio with a value of 1.4 (Ambrosia) and 1.8 (Zuchinni
Gray) was observed to increase total production, which could be
considered as a reference for zucchini cultivation. The optimal ratio
of 1.4 to 1.8 promoted increased total production, fruit count, and
enhanced calcium absorption. Moreover, the K
+
/Ca
2+
+Mg
2+
ratio of
1.4 led to an increase in leaf calcium content, while the potassium and
magnesium contents remained constant.
Literature cited
Aguilar-Carpio, C., Cervantes-Adame, Y.F., Sorza-Aguilar, P.J., & Escalante-
Estrada, J.A.S. (2022). Growth, yield, and protability of zucchini
(Cucurbita pepo L.) fertilized with chemical and biological sources.
Revista Terra Latinoamericana, 40, e1059. https://doi.org/10.28940/terra.
v40i0.1059
Alcántar-González, G., y Trejo-Téllez, L.I. (2010). Nutrición de cultivos. Colegio
de Posgraduados, Mundi–Prensa, México, 454 pp. ISBN 978-968-7462-
48-6
Cadahía-López, C. (2005). Fertirrigación. Cultivos agrícolas, frutales y
ornamentales. 3a Edición, Mundi-Prensa, Madrid, España, 631 pp. ISBN
84-8476-247-5
CPHA. (2004). Manual of fertilizers for high yield crops. California Plant Health
Association, Editorial Limusa. 366 pp. ISBN: 978-9681847661
Diovisalvi, N.V., Reussi-Calvo, N.I., Boxler, M., y García, F. (2021). Relevamiento
de calcio, magnesio, potasio y micronutrientes en zonas con diferente
productividad de soja. Ciencia del Suelo, 39(1), 63-79. https://www.
scielo.org.ar/pdf/cds/v39n1/1850-2067-cds-39-01-63.pdf
Estrada-Herrera, R., Hidalgo-Moreno. C., Guzmán-Plazola, R., Almaraz-Suárez,
J.J., Navarro-Garza, H., & Etchevers-Barra, J.D. (2017). Soil quality
indicators to evaluate soil fertility. Agrociencia, 51, 813-831. https://
www.scielo.org.mx/pdf/agro/v51n8/1405-3195-agro-51-08-813-en.pdf
Havlin, J.L., Tisdale, S.L., Nelson, W.L., & Beaton, J.D. (2017). Soil fertility and
fertilizers: An Introduction to Nutrient Management. 8th edition, India
Education Services Pvt. Ltd: Pearson. ISBN 978-93-325-7034-4
INEGI. (2014). Anuario estadístico y geográco de Puebla. Instituto Nacional de
Estadística y Geografía, México. https://www.inegi.org.mx
Maroto-Borrego, J.V. (2002). Horticultura herbácea especial. 5ª Edición, Ediciones
Mundi-Prensa, España, 704 pp. ISBN 978-8484760429
Melito, S., Ronga, D., Marceddu, D., Kallikazarou, N.I., Antoniou, MG., &
Giannini, V. (2023). Organo-mineral fertilizer containing struvite from
liquid digestate for Cucurbita pepo L. seedling production. Journal of
Soil Science and Plant Nutrition, 23, 6707-6720. https://doi.org/10.1007/
s42729-023-01524-9
Moreno-Reséndez, A., Reyes-Carrillo, J.L., Preciado-Rangel, P., Ramírez-
Aragón, M.G., y Moncayo-Luján, M.R. (2019). Desarrollo de la
calabacita (Cucurbita pepo L.) con diferentes fuentes de fertilización
bajo condiciones de invernadero. Ecosistemas y Recursos Agropecuarios,
6(16), 145-151. https://doi.org/10.19136/era.a6n16.1803
Neocleous, D., & Savvas, D. (2018). Modelling Ca
2+
accumulation in soilless
zucchini crops: Physiological and agronomical responses. Agricultural
Water Management, 203, 197-206. https://doi.org/10.1016/j.
agwat.2018.03.017
Purquerio, L.F.V., Mattar, G.S., Duart, A.M., de Moraes, C.C., Araújo, H.S., &
Santos, F.F.D. (2019). Growth, yield, nutrient accumulation and export
and thermal sum of Italian zucchini. Horticultura Brasileira, 37, 221-227.
http://dx.doi.org/10.1590/S0102-053620190214
Rodas-Gaitán, H.A., Rodríguez-Fuentes, H., Ojeda-Zacarías, Ma. del C., Vidales-
Contreras, J.A., y Luna-Maldonado, A.I. (2012). Curvas de absorción
de macronutrientes en calabacita italiana (Cucurbita pepo L.). Revista
Fitotecnia Mexicana, 35(5), 57–60. https://revistatotecniamexicana.org/
documentos/35-3_Especial_5/10r.pdf
Santos-Coello, B., y Ríos-Mesa, D. (2016). Cálculo de soluciones nutritivas en
suelo y sin suelo. Servicio de Agricultura y Desarrollo Rural, Cabildo
Insular de Tenerife, España, 113 pp. ISBN 978-84-15012-87-0
SDR. (2007). Cadenas productivas agropecuarias y acuícolas del Estado de
Puebla. Secretaría de Desarrolla Rural, Gobierno del Estado de Puebla,
México, pp. 89-90.
Seth, A., Gothelf, R., & Shenker, M. (2018). The K to (Ca + Mg) ratio eect
on potassium availability for plants - splitting soil- from plant-related
interactions. In: 20th EGU General Assembly, Geophysical Research
Abstracts, Vienna, Austria, 20, p. 9425.
SIAP. (2023). Anuario estadístico de la producción agrícola. Servicio de
Información Agroalimentaria y Pesquera, México. https://nube.siap.gob.
mx/cierreagricola/
Statgraphics Centurion XVI version 16.1.18 for Windows. ©StatPoint
Technologies, Inc., 1982-2012, USA.
Villalobos, F.C., Mateos, L., Orgaz, F., y Fereres, E. (2009). Fitotecnia: Bases y
tecnologías de producción agrícola. 2a edición, Editorial Mundi-Prensa.
Madrid, España, 496 pp. ISBN 978-84-8476-037-5