A salinidade da água de irrigação é um dos grandes entraves da agricultura moderna, podendo causar danos ao metabolismo e, consequentemente, ao desenvolvimento das plantas. Atualmente há uma grande demanda por substâncias que possam atenuar tais efeitos, dentre elas destaca-se o ácido salicílico. Com isso, objetivou-se avaliar os efeitos da aplicação de ácido salicílico na cultura da melancia (Citrullus lanatus L.) sob estresse salino. O delineamento experimental foi em blocos casualizados, em esquema fatorial incompleto, com quatro repetições e duas plantas por repetição. Os tratamentos resultaram da combinação de cinco concentrações de ácido salicílico (0,00; 0,15; 0,50; 0,85 e 1,00 mM) e cinco condutividades elétricas da água de irrigação (0,50; 1,01; 2,25; 3,49 e 4,00 dS m^-1). Aos 30 dias após transplantio foram avaliados o desenvolvimento, trocas gasosas, índices e fluorescências de clorofila. Os dados foram submetidos a análise de variância e em seguida foram produzidas bandas de confiança (confbands) e correlação de Pearson. A aplicação de ácido salicílico (até 0,85 mM) apresenta efeitos benéficos para a morfofisiologia da melancia, enquanto o aumento da condutividade elétrica da água de irrigação pode apresentar efeitos deletérios.

Aim: The aim of this work was to evaluate the effect of salicylic acid on gaseous changes, growth and basil biomass (Ocimum basilicum L. cv. Cinnamon) submitted to saline stress. Study Design: The experiment had conducted in a randomized incomplete block design (5x5- Compound Central Box) with five replicates. Place and Duration of Study: The experiment had carried out at the Agrarian Sciences Center of the Federal University of Paraíba, Areia, PB, between May and August 2017. Methodology: Basil plants were used cv. Cinnamon, where they were planted in pots of 5 dm³. Five electrical conductivities of the irrigation water (0.5, 1.3, 3.25, 5.2, 6.0 dS m^-1) and five doses of salicylic acid (0.0, 0.29, 1.0, 0.71, 2.0 and 2.0 mM). The following variables had evaluated: gas exchange, fluorescence and chlorophyll index, growth and fresh basil phytomass. Results: The increase of electrical conductivity of irrigation water negatively affected the growth (height of plants, number of leaves, stem diameter and leaf area), phytomass and gas exchange of basil. The application of salicylic acid had no significant effect, however, the application of this acid up to 1.0 mM positively affected most of the variables analyzed. Conclusion: Our results show that 1 mM of salicylic acid applied during the basil plants growth in saline stress conditions, affected positively to biomass and gas exchange.

Although not considered an essential element, silicon can be used to increase crop productivity, especially under stress conditions. In this sense, the objective was to evaluate the gas exchange of beet plants irrigated with saline water depending on the application of silicon. The experiment was conducted in a randomized block design, in a 5 x 5 factorial, referring to five levels of electrical conductivity of irrigation water (ECw): (0.5; 1.3; 3.25; 5.2 and 6.0 dS m-1) and five doses of silicon (0.00; 2.64; 9.08; 15.52 and 18.16 mL L-1), with six beet plants as an experimental unit. The effect of treatments on beet culture was evaluated at 30 and 60 days after irrigation with saline water from measurements of internal carbon concentration, stomatal conductance, net photosynthesis rate, instantaneous water use efficiency and instantaneous carboxylation efficiency using the LCpro+Sistem infrared gas analyzer (IRGA). Irrigation with saline water reduced the gas exchange of beet plants at 60 days after irrigation, but at 30 days after irrigation, the use of saline water increased stomatal conductance, transpiration rate and internal carbon concentration. The application of silicon decreased stomatal conductance, internal carbon concentration and efficiency in the use of water, but increased the rate of net photosynthesis, the rate of transpiration and instantaneous efficiency of carboxylation at 30 and 60 days after irrigation.

The water in semiarid regions contains salts in excess. When good quality water is not available it is necessary to use strategies that can make feasible the use of saline water. The aim of this study was to evaluate the effects of the application of the plant growth regulator on the culture of basil stressed with salt. The experiment was carried out in a randomized block design by the matrix “Central Box Compound”. Shoot height, stem diameter, leaf area, dry masses and soil chemical characteristics were evaluated. The salinity of the irrigation water causes reduction of the basil growth parameters, with the exception of the inflorescence dry mass. Plant growth regulator applications have effect on basil growth when plants are irrigated with saline water.

The radish is a short-cycle vegetable that has excellent nutritional and medicinal properties. It is considered rustic, meaning it tolerates adverse conditions with the possibility of being irrigated with saline water, which creates stress. In this context, this study aimed to evaluate the effect of electrical conductivities in irrigation water and doses of ascorbic acid on the agronomic performance and gaseous exchanges of radishes. This experiment was carried out in a protected environment at the Agricultural Sciences Center of the Federal University of Paraíba, Areia, Paraíba (Brazil). The experiment design used randomized blocks with five doses of ascorbic acid (0.0, 0.29, 1.0, 1.71 and 2.0 mM) and five electrical conductivities in the irrigation water (0.5, 1.3, 3.25, 5.2 and 6.0 dS m-1), with four replicates. The growth, gas exchange and production were evaluated. The doses of ascorbic acid were not significant. The increase in the electrical conductivities of the irrigation water provided a reduction in the agronomic performance and gas exchanges, except for the net photosynthesis, water use efficiency and instantaneous carboxylation efficiency, which were not significant. There was a relationship between the net photosynthesis, transpiration, internal concentration of CO2 and water use efficiency and the stomatal conductance. The agronomic performance and gaseous exchanges of the radish culture were influenced by the salinity. The foliar application of ascorbic acid did not influence the agronomic yield and gaseous exchanges of the radishes at the tested doses.

Organic fertilizer stimulates soil microbial activity, contributing to the decomposition of organic residues and nutrient release, thereby helping to reduce the negative effects of soil salinity. The use of Trichoderma can enhance nutrient availability to plants and increase their resistance to abiotic stresses, such as salinity stress. Therefore, this study aimed to determine the effects of organic fertilizer on green maize plants under soil inoculation with Trichoderma harzianum and salinity stress. The experiment was conducted during the 2022 and 2023 growing seasons in Redenção municipally, Ceará, Brazil. A randomized complete block design was used, arranged in a split–split plot scheme with four replications. The main plots consisted of two electrical conductivities of irrigation water (ECw): A1—0.3 dS m⁻¹ and A2—3.0 dS m⁻¹. The subplots comprised three doses of well-composted cattle manure (0, 10, and 20 t ha⁻¹), and the sub-subplots represented soil inoculation (TI) or non-inoculation (NI) with the Trichoderma harzianum-based biostimulant. Irrigation with saline water reduced maize growth and yield; however, these effects were mitigated by Trichoderma harzianum and organic fertilizer. Inoculation was particularly effective under lower electrical conductivity conditions. The combination of 10 t ha⁻¹ of cattle manure with Trichoderma inoculation showed the highest productive efficiency.