Keywords:

Cucumis sativus L.

Vegetable

Wood vinegar

Biostimulant

Inuence of pyroligneous acid on cucumber cultivation under organoponic conditions

Influencia del ácido piroleñoso sobre el cultivo de pepino en condiciones de organopónico

Inuência do ácido pirolenhoso no cultivo de pepino em condições organopônicas

Liliana Rondón-Estrada

Ernesto Javier Gómez-Padilla

Francisco Guevara-Hernández

Manuel Alejandro La O-Arias

Mariela B. Reyes-Sosa

Roberto Alfonso Viltres-Rodríguez

1,5

Rev. Fac. Agron. (LUZ). 2024, 41(3): e244126

ISSN 2477-9407

DOI: https://doi.org/10.47280/RevFacAgron(LUZ).v41.n3.06

Crop production

Associate editor: Dr. Jorge Vilchez-Perozo

University of Zulia, Faculty of Agronomy

Bolivarian Republic of Venezuela

Maestría en Ciencias en Producción Agropecuaria Tropical.

Universidad Autónoma de Chiapas, Chiapas (México).

Doctorado en Ciencias Agropecuarias y Sustentabilidad

(DOCAS). Universidad Autónoma de Chiapas. Tuxtla

Gutiérrez, Chiapas (México).

Facultad de Ciencias Agronómicas Campus V, Villaores-

Universidad Autónoma de Chiapas (México).

Facultad de Ciencias Agronómicas, Cátedras CONAHCYT-

UNACH, Villaores, Chiapas-Universidad Autónoma de

Chiapas (México).

Facultad de Ciencias Agropecuarias, Universidad de

Granma, Bayamo (Cuba).

Received: 27-05-2024

Accepted: 15-07-2024

Published: 08-08-2024

Abstract

Pyroligneous acid is recognised as an eective biostimulant in

a wide range of crops, improving processes such as germination,

growth and yield, as well as inducing stress tolerance and

increasing plant resistance to adverse conditions. To evaluate

the eect of applying pyroligneous acid (PA) foliarly and on the

substrate on the growth, development and yield of cucumber crops,

an experiment was set up under organoponic conditions in Bayamo,

Granma, Cuba. Seven treatments were used, consisting of PA doses

of 5 mL.L

-1

foliar (FD1), 10 mL.L

-1

foliar (FD2), 15 mL.L

-1

foliar

(FD3), 5 mL.L

-1

substrate (SD1), 10 mL.L

-1

(SD2), 15 mL.L

-1

(SD3)

and an absolute control. The treatments were established using a

completely randomised design. Each treatment was replicated three

times, with a sample size of 15 plants per replicate. The product

was applied at 7, 14 and 21 days after germination. At 21 days after

germination, stem length (cm), stem base diameter (cm), number

of leaves, leaf diameter and length (cm), number of branches formed

per plant and yield (t.ha

-1

) were evaluated. The application of PA,

both on the leaves and on the substrate, promoted plant growth

and development at doses of 5 and 10 mL.L

-1

. Similarly, the yield-

related variables also showed improvements with the application of

the product, highlighting that the greatest stimulation was observed

when the dose of 5 mL.L

-1

was applied foliarly.

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). 2024, 41(3): e244126 July-September. ISSN 2477-9407.

2-7 |

Resumen

El ácido piroleñoso es reconocido como un bioestimulante

efectivo en una gran variedad de cultivos, ya que mejora procesos

como la germinación, el crecimiento y el rendimiento, además de

inducir tolerancia al estrés y aumentar la resistencia de las plantas

a condiciones adversas. Para evaluar el efecto de la aplicación de

ácido piroleñoso (AP) aplicado foliarmente y al sustrato sobre el

crecimiento, desarrollo y rendimiento del cultivo de pepino, se

estableció un experimento en condiciones de organopónico en

Bayamo, Granma, Cuba. Se utilizaron siete tratamientos consistentes

en dosis de AP a razón de 5 mL.L

-1

foliar (FD1), 10 mL.L

-1

foliar

(FD2), 15 mL.L

-1

foliar (FD3), 5 mL.L

-1

sustrato (SD1), 10 mL.L

-1

(SD2), 15 mL.L

-1

(SD3) y un control absoluto. Los tratamientos se

establecieron sobre un diseño completamente aleatorizado. Cada

tratamiento se repitió tres veces, con un tamaño de muestra de 15

plantas por repetición. El producto se aplicó a los 7, 14 y 21 días

después de la germinación. A los 21 días después de la germinación,

se evaluó la longitud del tallo (cm), diámetro de la base del tallo (cm),

número de hojas, diámetro y longitud de las hojas (cm), cantidad

de ramas formadas por planta y rendimiento del cultivo (t.ha

-1

). La

aplicación de AP, tanto de forma foliar como al sustrato, promovió

el crecimiento y desarrollo del cultivo con dosis de 5 y 10 mL.L

-1

Asimismo, las variables relacionadas con el rendimiento también

mostraron mejoras con la aplicación del producto, destacando que

la mayor estimulación se observó al aplicar la dosis de 5 mL.L

-1

manera foliar.

Palabras clave: Cucumis sativus L., vegetales, vinagre de madera,

bioestimulante

Resumo

O ácido pirolenhoso é reconhecido como um bioestimulante ecaz

em uma ampla variedade de culturas, pois melhora processos como

germinação, crescimento e rendimento, além de induzir a tolerância

ao estresse e aumentar a resistência das plantas a condições adversas.

Para avaliar o efeito da aplicação do ácido pirolenhoso (AP) aplicado

foliarmente e no substrato sobre o crescimento, o desenvolvimento e o

rendimento das culturas de pepino, foi realizado um experimento em

condições organopônicas em Bayamo, Granma, Cuba. Foram usados

sete tratamentos, consistindo em doses de AP de 5 mL.L

-1

foliar (FD1),

10 mL.L

-1

foliar (FD2), 15 mL.L

-1

foliar (FD3), 5 mL.L

-1

de substrato

(SD1), 10 mL.L

-1

(SD2), 15 mL.L

-1

(SD3) e um controle absoluto.

Os tratamentos foram estabelecidos em um projeto completamente

aleatório. Cada tratamento foi repetido três vezes, com um tamanho

de amostra de 15 plantas por replicação. O produto foi aplicado aos 7,

14 e 21 dias após a germinação. Aos 21 dias após a germinação, foram

avaliados o comprimento do caule (cm), o diâmetro da base do caule

(cm), o número de folhas, o diâmetro e o comprimento das folhas

(cm), o número de ramos formados por planta e a produtividade da

cultura (t.ha

-1

). A aplicação de AP, tanto foliar quanto no substrato,

promoveu o crescimento e o desenvolvimento da cultura nas doses

de 5 e 10 mL.L

-1

. Da mesma forma, as variáveis relacionadas à

produtividade também apresentaram melhorias com a aplicação do

produto, destacando-se que o maior estímulo foi observado quando se

aplicou a dose de 5 mL.L

-1

por via foliar.

Palavras-chave: Cucumis sativus L., vegetais, vinagre de madeira,

bioestimulante

Introduction

Cucumber (Cucumis sativus L.) is a globally consumed vegetable,

with an annual production exceeding 93.5 million tons and yields of up

to 40.5 t.ha

-1

. It is not only consumed as food but also has applications

in the pharmaceutical and cosmetic industries (FAOSTAT, 2022; Jia

& Wang, 2021). The Caribbean region’s production is relatively low,

with approximately 9,000 hectares yielding 122,724.85 tons at an

average of 13.74 t.ha

-1

(FAOSTAT, 2022).

According to the National Oce of Statistics and Information

(Ocina Nacional de Estadística e Información de la República de

Cuba (ONEI), 2023), in Cuba, over 19,900 hectares are planted

annually, yielding around 79,185 tons with an average yield of

12.76 t.ha

-1

. Compared to other countries in the region, the yields

are relatively low. However, with the use of appropriate cultivation

technology, yields can increase to over 50 t.ha

-1

(FAOSTAT, 2022).

One common method of cucumber cultivation nationwide is

through organoponic. Organoponics in Cuba represents an intensive

system of urban agriculture, based on sustainable agroecological

principles. These principles incorporate integrated pest and disease

management, plant nutrition with organic amendments, biostimulants

and biofertilizers, and cultivation practices that minimize

environmental impact. These systems permit the continuous

cultivation of vegetables and other short-cycle crops, thereby

supporting local production in urban and peri-urban areas throughout

the year (Mendivil et al., 2020; Orberá et al., 2021; Rodríguez et al.,

2020).

Several biostimulants are used in organoponic systems, including

humic and fulvic acids, amino acids, algae and plant extracts,

chitosan, inorganic compounds, benecial fungi, and bacteria

(Galbán et al., 2021). In recent years, a substance called wood

vinegar or pyroligneous acid has been incorporated into this group of

substances, a product resulting from the combustion process of wood

(Singh et al., 2020).

Pyroligneous acid (PA) is derived from pyrolysis, a process

involving organic matter’s chemical breakdown through heat without

oxygen for a specied duration (Catacora et al., 2019). This vinegar

comprises aromatic and aliphatic compounds, hydrocarbons, and

various oxygenated compounds like phenols, furans, alcohols, acids,

ethers, aldehydes, and ketones, along with macro and microelements,

phytohormones, and vitamins C and K (Catacora et al., 2019;

Viltres & Alarcón, 2022). Due to these properties, PA is increasingly

employed in agriculture, notably as a soil conditioner, rooting agent,

and foliar fertilizer (Lescay et al., 2023).

In cucumber cultivation, studies have focused on seed treatment

to enhance germination, exploring doses that stimulate physiological

processes or may aect them. Additionally, research has targeted pest

control strategies (Catacora et al., 2019).

In horticultural crops such as lettuce and peppers, wood vinegar

has demonstrated ecacy in stimulating growth, development, and

yield. However, there is a paucity of documentation on its application

in Cuban cucumber cultivation (Galbán et al., 2021). The use of

pyroligneous acid in cucumber cultivation is an opportunity for two

important reasons. Firstly, it improves the yield of the crop. Secondly,

it allows the agricultural use of Marabú, one of the main weeds

in Cuban elds, by using it as a raw material for extraction. The

objective of this study was to determine the inuence of pyroligneous

acid, obtained from Marabú (Dichrostachys cinerea L.) biomass,

on the growth, development, and yield variables of cucumber under

organoponic conditions.

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Rondón-Estrada et al. Rev. Fac. Agron. (LUZ). 2024 41(3): e244126

3-7 |

Materials and methods

The experiment was conducted under production conditions

at the “Las Caobas I” Organoponic in the city of Bayamo, Granma

province, Cuba (20°21’35.6”N-76°37’54.9”W). The variety used was

INIVIT P-2007, obtained from the Research Institute of Tropical Root

and Tuber Crops (INIVIT, Instituto Nacional de Investigaciones de

Viandas Tropicales). Planting was carried out at the end of May, with

plants spaced 30 cm apart in double rows on the bed with guards. The

nal evaluation harvest took place in mid-July. Decomposed bovine

manure organic matter with a C/N ratio of 15:1 was used as substrate,

homogeneously distributed over the surface of each bed and in the

same quantity, in order to control variations in its fertility gradient.

The agrotechnical management was carried out in a homogeneous

way throughout the experiment, following the recommendations of

the technical manual for organoponics, intensive orchards, and semi-

protected organoponics (as per its Spanish title, ‘Manual Técnico para

Organopónicos, Huertos Intensivos y Organoponía Semiprotegida’)

(Rodríguez et al., 2020).

A total of seven treatments were employed, derived from

the combination of two application methods and three dierent

concentrations. The rst application method consisted of foliar

spraying, whereby the entire leaf surface of each plant was uniformly

sprayed. To prevent the product from contacting the substrate, a plastic

cover was placed over the substrate during each application, and it was

removed 30 min after the product was applied. The second method

involved spraying directly onto the substrate in an approximately 15 cm

radius, starting at the base of the stem and continuing until the substrate

was visibly wet. Furthermore, three application concentrations of 5, 10,

and 15 mL.L

-1

were utilized (table 1).

Table 1. Description of treatments evaluating the eects of

pyroligneous acid (PA) applied to foliage and substrate

on cucumber plants grown under organoponic

conditions.

No. Treatments Denomination

1 FD1

mL.L

-1

of PA Foliar

2 FD2

mL.L

-1

of PA Foliar

3 FD3

mL.L

-1

of PA Foliar

4 SD1

mL.L

-1

of PA substrate

5 SD2

mL.L

-1

of PA substrate

6 SD3

mL.L

-1

of PA substrate

7 C Control

PA: Pyroligneous acid

The treatments were established in raised beds with borders,

each covering an area of 24 m². They were distributed according to a

completely randomized design, made feasible by ensuring substrate

homogeneity. Each treatment was replicated three times, with 15

plants per replicate. To avoid edge eects, two plants were removed

from each end of the plot.

Pyroligneous acid was obtained using the rapid pyrolysis process

described by Viltres and Alarcón (Viltres & Alarcón, 2022). The

pyroligneous acid used in this study was derived from Marabou plant

biomass (Dichrostachys cinerea L.). Specic data on the chemical

and biochemical composition of Marabu-derived pyroligneous acid

are not currently available. However, it has been shown that this

compound contains common components regardless of the biomass

used as the raw material. These components include phenols, acids

(such as acetic and formic acids), and alcohols (such as methanol

and ethanol). Other compounds present include furans, aldehydes,

ketones, ethers, and certain hydrocarbons (Viltres & Alarcón, 2022).

Three applications of PA were carried out on days 7, 14, and 21

after germination. Three Matabí brand backpack sprayers of 16 liters

each were used for these applications, one for each dose. Applications

were performed between 7:30 and 8:30 am to avoid product exposure

to intense sunlight and ensure optimal eectiveness. Furthermore,

cultural practices were performed according to the Organic Garden

and Intensive Gardening Manual (Rodríguez et al., 2020).

At 21 days after germination, evaluations were conducted on

variables related to crop growth and development, including stem

length (cm), stem base diameter (cm), leaf number, and number

of branches formed per plant. Measurements were made using a

caliper for stem base diameter and a exometer for stem length. The

number of leaves and branches formed per plant were also recorded.

Leaf area was estimated from its length and width, according to the

methodology described by Kemp (1960), using the equation; where ,

is the length of the leaf, is the width of the leaf and, is the correction

factor equal to 0.66. Leaf width was determined at the widest part,

while length was dened as the distance between the two most distant

points: from the tip of the lamina to the point of intersection of the

petiole with the midrib (Schrader et al., 2021).

Harvesting started 40 days after germination with an interval of

3 days between each harvest until the fth harvest. At each harvest,

all fruits from each plot were removed and weighed using an MKZ-

BAS-ACS209 digital balance. To determine the yield per treatment,

the total weight of all harvests from each replicate was summed and

the yield was calculated in kg.m

² and then estimated in t.ha

-1

. The

length of the stem and fruit was measured with a 3 m tape measure

and the width of the stem and fruit was measured with a caliper.

The data were processed using Statistica for Windows, version 10

(StatSoft, 2014). Cochran, Hartley-Bartlet tests were conducted to

determine homogeneity of variance, and the Kolmogorov-Smirnov

test was used to check for normal distribution. The results underwent

a simple analysis of variance, and the Tukey test (p≤ 0.05) was used

to determine dierences between treatments.

Results and discussion

Eect of pyroligneous acid on length and diameter of

cucumber stems

Pyroligneous acid exerted a positive inuence on various variables

related to the growth and development of the crop. This eect was

observed at 21 days after germination, following two applications of

the product. However, this behavior depended on the applied dose

and the application method, as dierences were observed among the

treatments used. According to this, stem length was mainly beneted

by foliar applications, showing signicant dierences compared to

when the product was applied directly to the substrate and near the

plant’s stem (gure 1a). In this case, the best results were obtained

with the treatment where PA was applied via foliar application at

doses of 5, 10, and 15 mL.L

-1

(FD1, FD2, and FD3).

This behavior may be associated with various mechanisms

involved in the uptake of pyroligneous acid compounds, which can

occur through multiple pathways.

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). 2024, 41(3): e244126 July-September. ISSN 2477-9407.

4-7 |

Figure 1. Inuence of pyroligneous acid applied to foliage and substrate on the length (a) and diameter (b) of cucumber stems grown

under organoponic conditions. FD1: 5 mL.L

-1

of foliar PA; FD2: 10 mL.L

-1

of foliar PA; FD3: 15 mL.L

-1

of foliar PA; SD1: 5 mL.L

-1

of substrate PA; SD2: 10 mL.L

-1

of substrate PA; SD3: 15 mL.L

-1

of substrate PA; C: control treatment. Bars with dierent letters dier

signicantly according to the Tukey test (p<0.05).

These include stomata, microcracks, and cuticular pores, as well

as direct cuticular uptake through the lipid matrix of the cuticle

(Halpern et al., 2015; Mellidou & Karamanoli, 2022).

The absorption of pyroligneous acid compounds is facilitated

by several factors, including the lipid and water solubility of these

compounds, the presence of natural surfactants, and environmental

conditions such as high humidity and temperature (Parađiković et

al., 2019; El Boukhari et al., 2020; Bell et al., 2022). Substances

such as phenolic compounds, organic acids (acetic acid), and volatile

compounds (acetone and methanol) have been demonstrated to be

readily absorbed by leaves (Pratyusha, 2022; Eichert & Fernández,

2023).

However, the application of the product to the substrate at a

dose of 15 mL.L

-1

(SD2) demonstrated a tendency to increase stem

length, while with SD2 and SD3, it exhibited a tendency to decrease.

Nevertheless, in both cases, the values exceeded those of the

control (gure 1a). The ecacy of the substrate application is likely

attributable to the ecient uptake of water-soluble compounds by

the roots, facilitated by the aqueous environment of the rhizosphere.

These water-soluble compounds include organic acids, sugars, amino

acids, and macro- and micronutrients (Kathpalia & Bhatla, 2018).

The impact of pyroligneous acid on stem diameter exhibited

varied outcomes, with an increase in stem thickness observed in

treatments where the product was directly applied to the substrate.

In fact, the most favorable outcome was observed when the product

was applied at a dose of 10 mL.L

-1

(SD2), closely followed by the

foliar application of 5 mL.L

-1

(FD1), with statistically similar results.

However, in treatments where higher doses of 15 mL.L

-1

were applied,

both foliar and to the substrate, stem diameter exhibited a tendency to

align with the control (gure 1b).

It has been reported that some compounds, such as water-soluble

phenols (e.g. ferulic acid), humic and fulvic acids, peptides and

oligopeptides, can be taken up by roots due to their solubility in both

lipids and water, as well as their appropriate molecular size (Chen

et al., 2022). This result supports the potential benets of substrate

application of the product, although higher doses may be necessary

compared to foliar application.

Inuence pyroligneous acid on leaf and branch formation and

leaf area

PA did not inuence leaf formation in plants, as there were no

signicant dierences between treatments, although a slight increase

was observed in the FD1 treatment (gure 2a). However, the number

of branches formed by plants was notable (gure 2b). Among the

treatments used, the one that exerted the most inuence on this

variable was the foliar dose of 10 mL.L

-1

(FD2), although foliar application

of 5 mL.L

-1

(FD1) and substrate application of 10 mL.L

-1

(SD2) yielded

similar results. Treatments with doses of 5 and 15 mL.L

-1

applied

to the substrate (SD1 and SD3) generated the lowest number of

branches, with results like the control (gure 2b).

However, the number of branches formed by plants was notable

(gure 2b). Among the treatments used, the one that exerted the most

inuence on this variable was the foliar dose of 10 mL.L

-1

(FD2),

although foliar application of 5 mL.L

-1

(FD1) and substrate application

of 10 mL.L

-1

(SD2) yielded similar results. Treatments with doses of

5 and 15 mL.L

-1

applied to the substrate (SD1 and SD3) generated the

lowest number of branches, with results like the control (gure 2b).

In Cucumis sativus, the application of pyroligneous acid may

have altered hormonal balance and nutrient distribution, favoring

branch formation over leaf development. This preference for branch

growth could be attributed to the meristematic activity induced by

pyroligneous acid compounds, particularly in secondary branches

where female owers begin to form (Liu et al., 2021; Luo et al.,

2023). Additionally, the photosynthetic capacity of green branches

enhances total photosynthetic surface area, facilitating ecient

energy production and compensating for reduced leaf formation

(Aschan & Pfanz, 2003; Sun et al., 2021).

The application of pyroligneous acid signicantly aected the leaf area

compared to the control. Foliar application of 5 mL.L

-1

(FD1) resulted in

greater leaf development (gure 3) compared to other concentrations and

regardless of the application method used. Intermediate concentrations of

10 mL.L

-1

, both foliar (FD2) and to the substrate (SD2), also achieved an

increase, although less than that obtained with FD1.

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Rondón-Estrada et al. Rev. Fac. Agron. (LUZ). 2024 41(3): e244126

5-7 |

Figure 2. Inuence of pyroligneous acid applied to foliage and substrate on the number of leaves (a) and branches (b) in cucumber plants

grown under organoponic conditions. FD1: 5 mL.L

-1

of foliar PA; FD2: 10 mL.L

-1

of foliar PA; FD3: 15 mL.L

-1

of foliar PA; SD1:

5 mL.L

-1

of substrate PA; SD2: 10 mL.L

-1

of substrate PA; SD3: 15 mL.L

-1

of substrate PA; C: control treatment. Bars with dierent

letters dier signicantly according to Tukey's test (p<0.05).

Figure 3. Inuence of pyroligneous acid applied to foliage and

substrate on the leaf area of cucumber plants grown

under organoponic conditions. FD1: 5 mL.L

-1

of foliar

PA; FD2: 10 mL.L

-1

of foliar PA; FD3: 15 mL.L

-1

of foliar

PA; SD1: 5 mL.L

-1

of substrate PA; SD2: 10 mL.L

-1

substrate PA; SD3: 15 mL.L

-1

of substrate PA; C: control

treatment. Bars with dierent letters dier signicantly

according to Tukey’s test (p<0.05).

Among the substrate applications, SD2 showed the best results.

It is important to note that higher concentrations (15 mL.L

-1

) did not

show signicant improvements, indicating that beyond this dose,

pyroligneous acid does not exert a positive eect. On the contrary, it

is possible that from this dose it acts by inhibiting cell growth. In fact,

studies suggest that at high doses, pyroligneous acid can act as an

herbicide (Korkalo et al., 2022; Rodrigues & Abbade, 2024).

Eect of pyroligneous acid on yield variables

The results demonstrate that yield-related variables, such as

number of formed fruits, as well as length and width of fruits, were

beneted by the application of pyroligneous acid (table 2). Treatment

FD1 (5 mL.L

-1

of PA) yielded the highest number of fruits per plant,

along with longer and wider fruits (table 2). Substrate application

similarly inuenced these variables, yielding comparable results.

Table 2. Eect of pyroligneous acid applied to foliage and

substrate on the number, length, and width of fruits of

cucumber plants grown under organoponic conditions.

Treatment

Number of fruits

per plant

Fruit length (cm) Fruit width (cm)

FD1

64.00a 21.34a 5.18a

FD2

59.00b 20.62ab 5.00ab

FD3

40.40d 21.09ab 4.36c

SD1

46.20c 20.74ab 4.60b

SD2

61.20ab 19.24ab 4.80ab

SD3

29.00e 19.07ab 4.44bc

20.20f 17.57b 4.00c

SD 2.69 0.33 0.08

FD1: 5

mL.L

-1

of foliar PA; FD2: 10 mL.L

-1

of foliar PA; FD3: 15 mL.L

-1

foliar PA; SD1: 5 mL.L

-1

of substrate PA; SD2: 10 mL.L

-1

of substrate PA; SD3:

15 mL.L

-1

of substrate PA; C: control treatment; SD: standard error of the mean.

Letters that are dierent in the columns dier signicantly according to the Tukey

test (p<0.05).

However, foliar application of 10 mL.L

-1

of PA (FD2) led to a

decrease in fruit number, with the lowest count observed at 15 mL.L

-1

(FD3). Interestingly, substrate-applied treatment SD1 with 15 mL.L

-1

of PA surpassed this count.

Signicant dierences in fruit length were minimal, with most

treatments yielding fruits between 19 and 21 cm, showing no notable

distinctions. However, the 5 mL.L

-1

dose tended to produce longer

fruits exceeding 21 cm, while the control treatment yielded the

shortest fruits at 19.07 cm (table 2).

More pronounced dierences were observed in fruit width between

treatments, as the best results were found when using the foliar

dose of 5 mL.L

-1

(FD1), followed by the dose of 10 mL.L

-1

(FD2).

However, good results were also found with substrate application,

especially with the 15 mL.L

-1

dose (SD2), which was statistically

like the foliar applications (table 2). When evaluating yield, a similar

trend to the rest of the variables analyzed previously can be observed

because the highest values were achieved when using the 5 mL.L

-1

foliar

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). 2024, 41(3): e244126 July-September. ISSN 2477-9407.

6-7 |

application dose (FD1) (gure 4). Yield in the other treatments used

decreased signicantly, although in all cases, they exceeded the control.

FD1 FD2 FD3 SD1 SD2 SD3 C

Yield (t.ha-1)

SEx=1.57

Figure 4. Inuence of pyroligneous acid (PA) applied to foliage

and substrate on cucumber crop yield grown under

organoponic conditions. FD1: 5 mL.L

-1

foliar PA; FD2:

10 mL.L

-1

foliar PA; FD3: 15 mL.L

-1

foliar PA; SD1: 5

mL.L

-1

substrate PA; SD2: 10 mL.L

-1

substrate PA; SD3:

15 mL.L

-1

substrate PA; C: control treatment. Bars with

dierent letters dier signicantly according to Tukey’s

test (p<0.05).

However, applications of 10 mL.L

-1

both foliarly and to the

substrate (FD2 and SD2) showed the second-best performance with

statistically similar results between them. Treatments with the lowest

results were obtained with FD3, SD1, and SD3, which behaved

similarly.

As observed, with foliar application, the best yield values were

achieved with the lowest doses of 5 mL.L

-1

(FD1), while in substrate

application, the dose that yielded the best results was 10 mL.L

-1

(SD2).

This indicates that foliarly, with a minimum dose, there is

adequate absorption of biostimulant elements and nutrients, resulting

in a positive conversion of these into yield. The increase in dose

leading to a decrease in yield suggests that at higher concentrations,

the product may have an opposite eect, acting as an inhibitor rather

than a biostimulant. The research ndings indicate that pyroligneous

acid can positively impact cucumber growth, development, and yield

when applied foliarly at a concentration of 5 mL.L

-1

or to the substrate

at 10 mL.L

-1

Therefore, future research could consider additional variables

related to yield, such as the proportion of male and female owers,

as well as others that occur at the biochemical, molecular, and

ultrastructural levels, which can explain variations and alterations

underlying the eects of pyroligneous acid on the growth and

development of cucumber and related species, which remain

incompletely understood.

Further research is required to elucidate processes such as the

uptake and distribution of pyroligneous acid compounds in the

plant, their hormonal inuence on cell division and dierentiation,

and interactions with environmental factors like light, temperature,

humidity, or substrate pH, as well as with nutritional variables such

as macronutrient and micronutrient availability. This will represent

a signicant advancement in this eld of study. Additionally,

research could focus on identifying the detrimental eects at the

cellular level that cause irreparable damage associated with specic

doses and compounds involved. This could potentially facilitate the

development of natural herbicides, oering a promising pathway for

sustainable growth.

Conclusions

Pyroligneous acid, applied both foliarly and to the substrate

at 5 mL.L

-1

and 10 mL.L

-1

respectively, is eective in stimulating

growth, development and yield variables in cucumber crops. The

most eective treatment is observed with a foliar application of 5 mL.L

-1

Recomendations

Further studies under controlled conditions are needed to elucidate

the biochemical and molecular mechanisms, as well as potential

structural variations at the cellular level, that explain the action of the

various compounds in pyroligneous acid.

Acknowledgments

We extend our gratitude to the University of Granma and the

administration of the organoponic "Las Caobas I" for their invaluable

support and contribution to this research. We also thank CONAHCYT

for the scholarship granted to the rst author, which allowed her to get

enrolled in the MCPAT postgraduate program at UNACH.

Literature cited

Aschan, G., & Pfanz, H. (2003). Non-foliar photosynthesis - A strategy of additional

carbon acquisition. Flora-Morphology, Distribution, Functional Ecology

of Plants, 198(2), 81–87. https://doi.org/10.1078/0367-2530-00080

Bell, J. C., Bound, S. A., & Buntain, M. (2022). Biostimulants in Agricultural

and Horticultural Production. In Warrington Ian (Ed.), Horticultural

Reviews (Vol. 49, pp. 35–95). John Wiley & Sons, Inc. https://doi.

org/10.1002/9781119851981.ch2

Catacora, P. M. H., Quispe, A. I. V., Julian, L. E., Zanabria, M. R. M., Roque,

C. M. J., & Zevallos, P. P. (2019). Caracterización de los componentes

químicos del ácido piroleñoso obtenido de 3 especies forestales, con nes

agrícolas en San Gabán, Puno (Perú). Ceprosimad, 7(2), 6–16. https://hdl.

handle.net/20.500.12955/2233

Chen, L., Cao, H., Huang, Q., Xiao, J., & Teng, H. (2022). Absorption, metabolism

and bioavailability of avonoids: a review. Critical Reviews in Food

Science and Nutrition, 62(28), 7730–7742. https://doi.org/10.1080/1040

8398.2021.1917508

Eichert, T., & Fernández, V. (2023). Uptake and release of elements by leaves and

other aerial plant parts. In Rengel Zed, Cakmak Ismail, & White Philip

J. (Eds.), Marschner’s Mineral Nutrition of Plants (Fourth Edition, pp.

105–129). Academic Press. https://doi.org/10.1016/B978-0-12-819773-

8.00014-9

El Boukhari, M. E. M., Barakate, M., Bouhia, Y., & Lyamlouli, K. (2020). Trends

in seaweed extract based biostimulants: Manufacturing process and

benecial eect on soil-plant systems. Plants, 9(3), 3–23. https://doi.

org/10.3390/plants9030359

FAOSTAT. (2022). Cultivos y productos de ganadería. Pepinos y pepinillos: área,

rendimiento y producción. https://www.fao.org/faostat/es/#data/QCL

Galbán, M. J. M., Martínez, B. D., & González, V. D. (2021). Efecto de extractos

de sustancias húmicas en la germinación y el crecimiento de plántulas de

arroz (Oryza sativa L.), cv. INCA LP-5. Cultivos Tropicales, 42(1), 1–12.

https://n9.cl/j0gur

Halpern, M., Bar-Tal, A., Ofek, M., Minz, D., Muller, T., & Yermiyahu, U. (2015).

Chapter Two - The Use of Biostimulants for Enhancing Nutrient Uptake.

In Sparks Donald L. (Ed.), Advances in Agronomy (Vol. 130, pp. 141–

174). Academic Press. https://doi.org/10.1016/bs.agron.2014.10.001

Jia, H., & Wang, H. (2021). Introductory Chapter: Studies on Cucumber. In

Wang Haiping (Ed.), Cucumber Economic Values and Its Cultivation

and Breeding (pp. 1–15). IntechOpen. https://doi.org/10.5772/

intechopen.87508

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Rondón-Estrada et al. Rev. Fac. Agron. (LUZ). 2024 41(3): e244126

7-7 |

Kathpalia, R., & Bhatla, S. C. (2018). Plant Mineral Nutrition. In Plant

Physiology, Development and Metabolism (pp. 37–81). Springer. https://

doi.org/10.1007/978-981-13-2023-1_2

Kemp, C. D. (1960). Methods of Estimating the Leaf Area of Grasses from

Linear Measurements. Annals of Botany, 24(4), 491–499. https://doi.

org/10.1093/oxfordjournals.aob.a083723

Korkalo, P., Hagner, M., Jänis, J., Mäkinen, M., Kaseva, J., Lassi, U., Rasa, K.,

& Jyske, T. (2022). Pyroligneous Acids of Dierently Pretreated Hybrid

Aspen Biomass: Herbicide and Fungicide Performance. Frontiers in

Chemistry, 9, 1–14. https://doi.org/10.3389/fchem.2021.821806

Lescay, B. E., Verdecia, V. A., & Matos, Y. R. (2023). El Ácido Piroleñoso de marabú,

una alternativa agroecológica para el combate de arvenses. Avances, 25(1),

35–44. http://avances.pinar.cu/index.php/publicaciones/article/

Liu, X., Chen, J., & Zhang, X. (2021). Genetic regulation of shoot architecture

in cucumber. Horticulture Research, 8(1), 143. https://doi.org/10.1038/

s41438-021-00577-0

Luo, H., Zhang, H., & Wang, H. (2023). Advance in sex dierentiation in

cucumber. Frontiers in Plant Science, 14:1186904, 1–11. https://doi.org/

https://doi.org/10.3389/fpls.2023.1186904

Mellidou, I., & Karamanoli, K. (2022). Unlocking PGPR-Mediated Abiotic Stress

Tolerance: What Lies Beneath. Frontiers in Sustainable Food Systems, 6,

1–8. https://doi.org/10.3389/fsufs.2022.832896

Mendivil, C., Nava, E., Armenta, A., Ayala, R., & Félix, J. (2020). Elaboración

de un abono orgánico tipo bocashi y su evaluación en la germinación

y crecimiento del rábano. Biotecnia, 22(1), 17–23. https://doi.org/https://

doi.org/10.18633/biotecnia.v22i1.1120

Ocina Nacional de Estadística e Información de la República de Cuba (ONEI).

(2023).

Anuario estadístico de cuba 2022. Agricultura, Ganadería,

Silvicultura y Pesca. 2023. https://www.onei.gob.cu/anuario-estadistico-

de-cuba-2022

Orberá, R. T. M., Bayard, V. I., & Cuypers, A. (2021). Biostimulation of Vigna

unguiculata subsp. sesquipedalis—Cultivar Sesquipedalis (Yardlong

Bean)—by Brevibacillus sp. B65 in Organoponic Conditions. Current

Microbiology, 78, 1882–1891. https://doi.org/10.1007/s00284-021-

02453-5

Parađiković, N., Teklić, T., Zeljković, S., Lisjak, M., & Špoljarević, M. (2019).

Biostimulants research in some horticultural plant species—A review.

Food and Energy Security, 8(2), 1–17. https://doi.org/10.1002/fes3.162

Pratyusha, S. (2022). Phenolic Compounds in the Plant Development and

Defense: An Overview. In M. Hasanuzzaman & K. Nahar (Eds.), Plant

Stress Physiology - Perspectives in Agriculture (1st ed., pp. 125–139).

https://doi.org/10.5772/intechopen.102873

Rodrigues, B. S., & Abbade, L. C. (2024). Herbicidal Eects of Pyroligneous

Acid for Control in Weed Seed Bank. Journal of Advances in Biology

& Biotechnology, 27(7), 1464–1469. https://doi.org/10.9734/jabb/2024/

v27i71108

Rodríguez, N. A., Companioni, C. N., Peña, T. E., Carrió. R. M. V., González,

B. R., Fresneda, B. J., Estrada. O. J., Cañet, P. F., Rey, G. R., Fernández,

G. E., Vázquez, M. L. L., Avilés. P. R., Arozarena, D. N., Dibut, A. B.,

Pozo, M. J. L., Cun, G. R., & Martínez, R. F. (2020). Manual técnico para

organopónicos, huertos intensivos y organoponía semiprotegida. (8va

ed.). Ministerio de la Agricultura. La Habana, Cuba. https://n9.cl/4o1j3

Schrader, J., Shi, P., Royer, D. L., Peppe, D. J., Gallagher, R. V, Li, Y., Wang, R.,

& Wright, I. J. (2021). Leaf size estimation based on leaf length, width

and shape. Annals of Botany, 128(4), 395–406. https://doi.org/10.1093/

aob/mcab078

Singh, S., Chakraborty, J. P., & Mondal, M. K. (2020). Pyrolysis of torreed

biomass: Optimization of process parameters using response surface

methodology, characterization, and comparison of properties of pyrolysis

oil from raw biomass. Journal of Cleaner Production, 272. https://doi.

org/https://doi.org/10.1016/j.jclepro.2020.122517

StatSoft, I. N. C. (2014). Statistica (Data Analysis Software System), Version 10

(Tulsa, Oklahoma, USA, StatSoft Inc.).

Sun, W., Ma, N., Huang, H., Wei, J., Ma, S., Liu, H., Zhang, S., Zhang, Z., Sui,

X., & Li, X. (2021). Photosynthetic contribution and characteristics of

cucumber stems and petioles. BMC Plant Biology, 21(454), 1–14. https://

doi.org/10.1186/s12870-021-03233-w

Viltres, R. R. A., & Alarcón, Z. A. (2022). Caracterización química del bio-aceite

de pirólisis rápida de biomasa. Revista Cubana de Química, 34(1), 131–

158. https://shre.ink/8eSG