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AJCS 18(07):382-387 (2024) ISSN:1835-2707

https://doi.org/10.21475/ajcs.24.18.07.pne-29

Physiological and sanitary quality of sorghum seeds under the effect

of oxalic and salicylic acid

Oliveira

2

, Sandra Helena Unêda-Trevisoli

2

1

Universidade Federal Rural de Pernambuco (UFRPE), Rua Dom Manuel

de Medeiros, s/n - Dois Irmãos, Recife - PE, 52171-900, Brasil

2

Universidade Estadual Paulista (UNESP)- Faculdade de Ciências

Agrárias e Veterinárias (FCAV) - Campus de Jaboticabal- Via de

acesso Prof. Paulo Donato Castellane s/ n - C.P. 14.870-900 -

Macaíba/RN - Brasil

5

Universidade Federal da Paraíba (UFPB)- Centro de Ciências Agrárias

(CCA) - 12 Rodovia, PB-079, 58397-000- Areia - PB, Brasil

Abstract: Sorghum is one of the world's most

important cereal crops, but it is susceptible to several

diseases, particularly fungal diseases, with seeds

being the main vehicle for dissemination. The

Accepted:

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objective of this study was to evaluate the effects of

salicylic acid (SA) and oxalic acid (OA) on the

physiological and sanitary quality of sorghum seeds.

The seeds

1 hour in solutions of OA (0.5, 1.0, 1.5, and 2.0 mM)

and SA (0.5, 1.0, 1.5, and 2.0 mM). A treatment with

resulted in higher germination in the first

germination count. The application of 1 mM OA and

both doses of SA (0.5 mM and 1 mM) promoted a

greater seedling vigor index (GVI). Seeds treated with

1 mM OA and doses of 0.5, 1, 1.5, and 2.0 mM SA, as

well as those treated with fungicide, had the highest

emergence rates, and with 1.5 mM SA, the highest

length of the longest root (LVEI). Seedlings from

seeds treated with 0.5, 1, and 1.5 mM SA and with

0.5 and 1.5 mM had the highest coleoptile length

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Keywords: seeds, endophytic fungi, resistance induction.

Abbreviation: SA_Salicylic Acid; OA_Oxalic Acid; LAFIT_Laboratory Of

Phytopathology; EIV_Emergence Velocity Index; GVI_Germination

Velocity Index; APL_Aerial Part Length; RL_Root Length; FG_First

Germination Count.

arid environments where other crops struggle to thrive (Nida et al.,

2019). It is also notable for its growth potential and significant role in

agricultural systems in Brazil (Maia et al., 2010).

Sorghum is susceptible to a wide range of diseases, which can restrict

its cultivation and diminish yields. Among the diseases affecting the

crop in Brazil, the most significant are anthracnose (

), downy mildew (

),

helminthosporium leaf blight (

), rust (

), ergot or sugar disease (Claviceps africana), and dry rot

(

) (Cota et al., 2010; Flavio et al., 2014).

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Seed treatments are essential for controlling pathogens associated

with seeds, as well as those inhabiting the soil, storage of fungi, and

early leaf pathogens. Under field conditions, effective seed treatment

can ensure an adequate plant stand, promote vigorous plant growth,

delay the onset of disease epidemics, and increase yield (Moraes,

2010). To reduce the use of chemicals in managing phytopathogens,

Pre-treatment with a non-lethal dose of oxalic acid has been shown to

activate defense mechanisms and significantly inhibit fungal growth

(Lehner et al., 2008). Jayaraj et al. (2010) demonstrated that the

application of oxalic acid enhanced rice resistance to

related proteins, thereby offering new strategies for managing this

disease in rice crops.

Salicylic acid (SA) is an endogenous plant growth regulator and is part

of a diverse group of plant phenolics (Pandey et al., 2013). It was the

first plant-derived phenolic compound proven to induce systemic

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Therefore, the objective of this study was to evaluate the effects of

salicylic acid and oxalic acid on the physiological and sanitary quality

of sorghum (Sorghum bicolor L.) seeds.

Results

treatments with 1 mM OA and 0.5 mM SA achieved the highest

percentage of seed germination at the first count (FG), recording 43%

and 48% respectively, which were comparable to the control. Higher

concentrations of OA (1.5 and 2.0 mM) and SA (1, 1.5, and 2 mM)

were observed to decrease FG compared to their lower concentrations.

The fungicide treatment resulted in the lowest FG (see Table 1).

Additionally, the application of 1 mM OA and 0.5 mM SA facilitated a

higher initial germination speed (GVI) in sorghum seeds, comparable

to the control. In contrast, treatments with fungicide and 2 mM SA

resulted in the lowest GVI (refer to Table 1).

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achieved the highest emergence velocity index (EVI), with seeds

treated with 1 mM SA recording the second-highest EVI (see Table 2).

Seedlings from sorghum seeds treated with SA at concentrations of

0.5 mM (5.41 cm), 1 mM (6.31 cm), and 1.5 mM (5.65 cm) and OA at

concentrations of 0.5 mM (6.36 cm) and 1.5 mM (5.35 cm) exhibited

the greatest lengths of the aerial parts (APL). The root lengths of the

treatment. The doses of 2 mM OA and 1, 1.5, and 2 mM SA reduced

the incidence of

the results achieved with the fungicide treatment. Additionally, seeds

treated with 2 mM OA and doses of 0.5, 1, 1.5, and 2 mM SA showed

a reduced incidence of

from the fungicide treatment. No concentration of the regulators

proved effective in reducing the incidence of

in the

seeds. The application of fungicide was the only treatment that

successfully reduced the incidence of this fungus.

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provides strong evidence against the null hypothesis that all

treatments have equal effects.

Discussion

Germination is influenced by seed vigor, as observed in seeds treated

seedling emergence in the field (Marcos Filho, 2015).

The fungicide acts indirectly to increase seedling emergence and the

emergence velocity index (EVI); it is not intended to increase seed

viability. However, if low emergence is due to a fungal attack, efficient

treatment with fungicides will increase these characteristics (Pinto,

2002). Seedlings that emerge rapidly from seeds treated with 1 mM

OA, 0.5, 1.5, and 2 mM SA, and fungicides are more prominent than

other seedlings with lower development, as they better utilize the

resources of the medium (Gustafson et al., 2004).

Seeds treated with SA (salicylic acid) at concentrations of 0.5, 1.0, and

Table 1. Germination (%), first count and germination velocity index (GVI) of sorghum (Sorghum bicolor) seedlings treated with

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Table 2. Emergence (%), emergence velocity index, aerial part length (APL-cm), root length (RL-cm) of sorghum (Sorghum bicolor)

acid (0.5 - SA0.5; 1.0 - SA1.0; 1.5 - SA1.5; and 2 - SA2.0 mM)

(Marcos Filho, 2015).

The fungi detected in this study are commonly reported in sorghum,

as noted by Flavio (2014). The application of SA triggers the induction

of response proteins (NPR1) and other defense genes, which enhance

plant resistance to pathogens (Yang et al., 2016). This mechanism

reduces the incidence of fungal infections. Sub-lethal concentrations

of oxalic acid (3 mM) can act as a pre-treatment to combat fungi, with

the 2.0 mM dose of OA being notably effective (Lehner et al., 2008).

Overall, fungicide treatments are expected to be highly efficient in

reducing pathogen presence (Moura et al., 2018). However,

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2.0 mM), show efficacy against specific fungal species like

Fungal attack on seeds reduces vigor by affecting germination (EL-

DAHAB et al. 2016). In this study, seeds with high disease incidence

(control) had higher germination than

The sorghum (

) seeds used in this study were

acquired from small-scale producers in the municipality of Prata,

Paraíba (7°41'35" S, 37°05'22" W), Brazil. These seeds hold cultural

significance for the local farmers, often referred to as 'seeds of

passion', and have been passed down through generations, from

father to son. Following the acquisition, the seeds were transported to

the Laboratory of Phytopathology (LAFIT) at the Center for Agrarian

Sciences, Federal University of Paraíba. At LAFIT, the seeds underwent

a sanitation process involving a 2-minute treatment with 1% sodium

hypochlorite. This procedure is critical as it removes surface