Gas exchange, photochemical efficiency and growth of hydroponic okra under salt stress and salicylic acid

Mendonça, Allysson J. T.; Lima, Geovani S. de; Soares, Lauriane A. dos A.; Sá, Valeska K. N. O. de; Silva, Saulo S. da; Torres, Rafaela A. F.; Ferreira, Jean T. A.; Gheyi, Hans R.

doi:10.1590/1983-21252024v3712143rc

Acessibilidade / Reportar erro

Brasil

Español English

sumário « anterior atual seguinte »

Sumário

Scientific Article • Rev. Caatinga 37 • 2024 • https://doi.org/10.1590/1983-21252024v3712143rc copy

Gas exchange, photochemical efficiency and growth of hydroponic okra under salt stress and salicylic acid

Trocas gasosas, eficiência fotoquímica e crescimento de quiabeiro hidropônico sob estresse salino e ácido salicílico

Authorship SCIMAGO INSTITUTIONS RANKINGS

ABSTRACT

Okra (Abelmoschus esculentus L.) is a shrub belonging to the Malvaceae family, which stands out for its rusticity and adaptation to soil and climatic conditions, being cultivated by small farmers, especially in the semi-arid region of Northeast Brazil. In this context, the objective of this study was to evaluate the effect of foliar application of salicylic acid as an attenuator of salt stress on leaf gas exchange, photochemical efficiency, and growth of okra cv. Canindé in a hydroponic system. The experiment was carried out using a Nutrient Film Technique - NFT hydroponic system in a greenhouse, in Pombal, PB, Brazil, from January to March 2022, in a completely randomized design, in a split-plot scheme, with the four levels of electrical conductivity of the nutrient solution - ECns (3.0, 5.0, 7.0, and 9.0 dS m^-1) considered as plots and four concentrations of salicylic acid – SA (0, 1.2, 2.4, and 3.6 mM) considered as subplots, with three replicates and two plants per plot. Increase in ECns levels from 3.0 dS m^-1 inhibited leaf gas exchange, photochemical efficiency, and growth of okra cv. Canindé in hydroponic cultivation, at 34 days after transplanting. Foliar application of SA at concentrations of 2.2 and 1.5 mM promoted increments in stomatal conductance and transpiration, respectively. Salicylic acid at concentration of 1.9 mM associated with saline nutrient solution of 9.0 dS m^-1 increased the variable fluorescence of okra plants cv. Canindé, at 34 days after transplantation.

Keywords:
Abelmoschus esculentus L; Moench; Salinity; Soilless cultivation; Osmoregulation

Nutrients	Fertilizers	Quantity (g 1000L^-1)
P/K	KH₂PO₄	136.09
K/N	KNO₃	101.10
Ca /N	Ca (NO₃)₂.4H₂O	236.15
Mg/S	MgSO₄.4H₂O	246.49
B	H₃BO₃	3.10
Mn/S	MnSO₄.4H₂O	1.70
Zn/S	ZnSO₄.7H₂O	0.22
Cu/S	CuSO₄	0.75
Mo	(NH₄)₆Mo₇O₂₄. 4H₂O	1.25
	EDTA – Na	13.9
Fe	FeSO₄	13.9

Sources of variation	Mean squares
Sources of variation	DF	gs	Ci	E	A
Saline nutrient solution (ECns)	3	0.24^**	7225.59^**	15.10^**	975.85^**
Linear regression	1	0.67^**	1627.60^ns	39.43^**	2037.99^**
Quadratic regression	1	0.007^ns	19967.52^**	0.67^ns	876.80^**
Residual 1	8	0.0015	519.7	0.105	17.62
Salicylic acid (SA)	3	0.02^**	48.12^ns	1.04^*	69.71^ns
Linear regression	1	0.035^**	42.50^ns	0.67^ns	66.96^ns
Quadratic regression	1	0.019^*	58.52^ns	2.14^**	73.28^ns
Interaction (ECns × SA)	9	0.006^ns	1189.17^ns	0.23^ns	18.91^ns
Residual 2	24	0.00325	376.75	0.25	15.69
CV 1(%)		8.15	20.64	5.46	9.77
CV 2(%)		12.00	17.57	8.43	9.22

Sources of variation	DF	Mean squares
Sources of variation	DF	F₀	F_m	F_v	F_v/F_m
Saline nutrient solution (ECns)	3	5530.06^**	35304.35^**	13004.36^**	0.0005^**
Linear regression	1	15512.37^**	102982.55^**	38557.35^**	0.0014^**
Quadratic regression	1	382.50^ns	949.63^ns	126.75^ns	0.00006^ns
Residual 1	8	115.31	1241.98	688.76	0.000067
Salicylic acid (SA)	3	282.81^ns	979.04^ns	612.35^ns	0.00008^ns
Linear regression	1	204.42^ns	47.25^ns	55.10^ns	0.00007^ns
Quadratic regression	1	231.88^ns	159.50^ns	776.02^ns	0.0001^ns
Interaction (ECns × SA)	9	113.08^ns	4901.41^ns	3949.12^*	0.00006^ns
Residual 2	24	431.50	4355.95	2596.27	0.000076
CV 1(%)		3.41	2.43	2.68	0.55
CV 2(%)		6.59	4.56	4.32	1.1
		F_s	Fms	Y	ETR
Saline nutrient solution (ECns)	3	32.17^ns	583.51^ns	0.0047^*	90.30^ns
Linear regression	1	86.40^ns	323.17^ns	0.0081^**	18.17^ns
Quadratic regression	1	0.52^ns	1276.17^ns	0.0057^*	219.09^ns
Residual 1	8	21.97	201.11	0.000375	59.63
Salicylic acid (SA)	3	39.22^ns	313.25^ns	0.0003^ns	14.71^ns
Linear regression	1	50.41^ns	736.75^ns	0.0005^ns	42.29^ns
Quadratic regression	1	21.33^ns	194.00^ns	0.00006^ns	1.52^ns
Interaction (ECns × SA)	9	32.69^ns	382.01^ns	0.0014^ns	46.59^ns
Residual 2	24	23.79	451.38	0.0013	51.58
CV 1(%)		8.01	9.75	4.08	15.84
CV 2(%)		6.93	12.15	5.9	12.26

Sources of variation	Mean squares
Sources of variation	DF	PH	SD	NL	LA
Saline nutrient solution (ECns)	3	930.04^**	85.59^**	201.56^**	212114569.00^**
Linear regression	1	2670.00^**	250.12^**	582.81^**	539704090.54^**
Quadratic regression	1	8.75^ns	1.02^ns	5.33^ns	83686080.53^**
Residual 1	8	63.07	5.67	4.45	794155.30
Salicylic acid (SA)	3	57.08^ns	0.42^ns	1.85^ns	2593428.32^ns
Linear regression	1	122.55ns	0.79ns	4.53ns	7383880.45ns
Quadratic regression	1	11.50ns	0.30ns	1.02ns	247326.60ns
Interaction (ECns ž SA)	9	67.54^ns	3.93^ns	6.11^ns	3390145.42^ns
Residual 2	24	81.12	6.06	8.20	1162664.70
CV 1(%)		11.38	15.21	11.93	16.34
CV 2(%)		12.91	15.72	16.19	19.77

Universidade Federal Rural do Semi-Árido Avenida Francisco Mota, número 572, Bairro Presidente Costa e Silva, Cep: 5962-5900, Telefone: 55 (84) 3317-8297 - Mossoró - RN - Brazil
E-mail: caatinga@ufersa.edu.br

Acompanhe os números deste periódico no seu leitor de RSS

[1] *Corresponding author: <allyssonjonhnny@hotmail.com>