BALANÇO DE SAIS E CRESCIMENTO INICIAL DE MUDAS DE PINHEIRA (Annona squamosa L.) SOB SUBSTRATOS IRRIGADOS COM ÁGUA SALINA     FRANCISCO VANIES DA SILVA SÁ¹; MARCOS ERIC BARBOSA BRITO²; ILKELAN BEZERRA FERREIRA³; PEDRO ANTÔNIO NETO³; LUDERLÂNDIO DE ANDRADE SILVA³ E FRANCISCLEUDO BEZERRA DA COSTA^{2 1} Eng. Agrônomo, Mestrando em Manejo de Solo e Água, Departamento de Ciências Ambientais e Tecnologia, Universidade Federal Rural do Semiárido, Mossoró, RN. E-mail: vanies_agronomia@hotmail.com ² Eng. Agrônomo, Doutor, Professor da Unidade Acadêmica de Ciências Agrárias, Universidade Federal de Campina Grande, Pombal, PB. E-mail: marcoseric@ccta.ufcg.edu.br; franciscleudo@yahoo.com.br ³ Graduando em Agronomia, Unidade Acadêmica de Ciências Agrárias, Universidade Federal de Campina Grande, Pombal, PB. E-mail: kelanb.ferreira@hotmail.com; pedroantonioufcg@gmail.com; luderlandioandrade@gmail.com     1 RESUMO   A salinidade da água e do solo são problemas que mais concorrem para redução no crescimento e rendimento das culturas, notadamente em regiões áridas e semiáridas, observando-se na identificação de estratégias de manejo, uma alternativa para os sistemas de produção. Assim, objetivou-se avaliar o uso de dois substratos na fase de formação de mudas de pinheira sob irrigação com águas salinizadas. O experimento foi realizado em casa de vegetação no município de Pombal, PB, Brasil, no período de maio a julho de 2011, sob delineamento experimental de blocos casualizados, com tratamentos distribuídos em esquema fatorial (5x2), sendo cinco níveis de salinidade da água (NS= 0,3; 1,2; 2,4; 3,6; 4,8 dS m^-1) e dois substratos (S) (S1= 50% de solo + 25% de esterco bovino + 25% de areia; S2= 40% de solo + 40% de esterco bovino + 20% de areia), repetido em três blocos, totalizando trinta parcelas experimentais, sendo cada uma constituídas por 10 plantas. O experimento foi conduzido durante 45 dias após a semeadura, quando foram avaliadas as características químicas do solo, a emergência e o crescimento inicial das plantas. A irrigação com água salina aumentou a salinidade do substrato, sendo está menos intensa no substrato 2. As altas concentrações de sais na água de irrigação inibem a emergência, o crescimento e o ganho de biomassa das plântulas de pinheira. As plantas de pinheira alcançaram o melhor desenvolvimento quando cultivadas no substrato 2. A salinidade da água de irrigação até 1,2 dSm^-1 não compromete a formação de mudas de pinheira. Palavras-chave: estresse salino, formação de mudas, matéria orgânica. SÁ, F.V.S;  BRITO, M.E.B.; FERREIRA, I.B.; ANTÔNIO NETO, P.; SILVA, L.A.; COSTA, F.B SALT BALANCE AND INITIAL GROWTH OF CUSTARD APPLE UNDER SUBSTRATES IRRIGATED WITH SALINE WATER         2 ABSTRACT   Water and soil salinity are the major pitfalls which contribute to reduction in growth and crop yield, especially in arid and semiarid regions. Identification of management strategies is an alternative tool for the crop system. Thus, the objective of this study was to evaluate the use of two substrates in the seedling stage of custard apple under irrigation with saline water. The experiment was carried out in a greenhouse in the municipality of Pombal, PB, Brazil, from May to July 2011, using randomized blocks and treatments in a factorial design (5 x 2) with five levels of water salinity ( 0.3; 1.2; 2.4; 3.6 and 4.8 dS m-1). Two substrates (S) (S1 = 50% soil + 25% manure + 25% sand; S2 = 40% soil+ 40% manure + 20% sand) repeated in three blocks were used, amounting to 30 plots with 10 plants each. The experiment was conducted for 45 days after sowing, and then, chemical characteristics of the soil solution, emergence and initial growth of plants were evaluated. Irrigation with saline water increased substrate salinity, which was lower in the substrate 2. High concentrations of salts in the irrigation water inhibited emergence, growth and gain of biomass of custard apple seedlings. Plants of custard apple achieved their best development when cultivated in the substrate 2 containing 40% soil, 40% manure and 20% sand. Salinity of irrigation water up to 1.2 dSm-1 did not compromise seedling growth of custard apple. Keywords: Annona squamosa L., salt stress, seedling production, organic matter.

However, for pot cultivation, there are few commercial cultivars available, since most plants of Capsicum are relatively large and were selected for field cultivation to produce fruits for fresh consumption or for industrial processing (^{Finger et al., 2012}).

Cotton is one of the most exploited crops in the world, being one of the most important for the Brazilian Northeast. In this region, the use of irrigation is often necessary to meet the water demand of the crop. Water is often used from underground wells that have a large amount of salt in their constitution, which can compromise the development of crops, so it is vital to adopt strategies that reduce salt stress effects on plants, such as the foliar application of hydrogen peroxide. Thus, the objective of this study was to evaluate the effects of foliar application of hydrogen peroxide on the gas exchange, growth, and production of naturally colored cotton under salt stress in the semi-arid region of Paraíba, Brazil. The experiment was carried out in a randomized block design in a 5 × 5 factorial scheme, with five salinity levels of irrigation water—ECw (0.3, 2.0, 3.7, 5.4 and 7.1 dS m⁻¹)—and five concentrations of hydrogen peroxide—H₂O₂ (0, 25, 50, 75 and 100 μM), and with three replicates. The naturally colored cotton ‘BRS Jade’ had its gas exchange, growth, biomass production, and production reduced due to the effects of salt stress, but the plants were able to produce up to the ECw of 3.97 dS m⁻¹. Foliar application of hydrogen peroxide at the estimated concentrations of 56.25 and 37.5 μM reduced the effects of salt stress on the stomatal conductance and CO₂ assimilation rate of cotton plants under the estimated ECw levels of 0.73 and 1.58 dS m⁻¹, respectively. In turn, the concentration of 12.5 μM increased water-use efficiency in plants subjected to salinity of 2.43 dS m⁻¹. Absolute and relative growth rates in leaf area increased with foliar application of 100 μM of hydrogen peroxide under ECw of 0.73 and 0.3 dS m⁻¹, respectively. Under conditions of low water salinity (0.3 dS m⁻¹), foliar application of hydrogen peroxide stimulated the biomass formation and production components of cotton.

Minimally processed fruits undergo changes that require careful monitoring. This study aimed to assess the effectiveness of edible coatings based on chitosan and gelatin using various application techniques for minimally processed papayas. The treatments included: control (distilled water), 1% chitosan, 4% gelatin, 1% chitosan + 4% gelatin (blend), and 1% chitosan with a 4% gelatin undercoat (layer-by-layer). The coatings’ infrared spectroscopies (FTIR) were analyzed, and the fruits’ fresh mass, firmness, pulp color (L*, a*, b*, and hue angle), pH, titratable acidity, soluble solids, ascorbic acid, phenolic compounds, lycopene, β-carotene, total sugars, and catalase activity were measured. The results revealed that gelatin and the layer-by-layer treatment positively influenced the preservation of minimally processed papaya. These coatings effectively reduced fresh mass loss while maintaining firmness and the characteristic orange color of the mesocarp. Furthermore, the treated samples consistently exhibited low soluble solids content during the storage period, with minimal variations in acidity, thereby influencing the maturation process. Gelatin coatings demonstrated low polyphenol content, while the layer-by-layer treatment showed no significant changes in vitamin C levels. Lycopene and β-carotene levels remained stable throughout the storage period, with a slight increase observed in total sugars. Consequently, the application of gelatin polymers and the undercoat treatment (LBL) represents a viable alternative for extending the shelf life of minimally processed papayas for at least eight days.

The aim of this study was to examine the drying kinetics of Spondias purpurea L. fruits at various maturation stages (I to V) using a range of mathematical models (Henderson and Pabis, Lewis, Logarithmic, Midilli, and Page). Additionally, an assessment of the resulting flours' quality was conducted. The stabilization phase of S. purpurea fruit drying kinetics commenced at 420 min for maturation stages I and III, and at 480 min for the remaining stages. All employed mathematical models effectively characterized the drying process, exhibiting R ² values exceeding 0.99, MSD below 0.03, and X ² below 0.0009. Flours demonstrated increased color intensity with higher levels of flavonoids and anthocyanins, showing a positive correlation. Immature fruits yielded flours with elevated titratable acidity, total chlorophylls, phenolic compounds, and density. In contrast, fruits in the final maturation stages produced flours with higher yield, levels of reducing sugars, total carotenoids, flavonoids, and anthocyanins. The results indicate that flours derived from ripe fruits exhibited higher yield, moisture content, pH, soluble solids, and reducing sugars, while titratable acidity was higher in green fruits. Bioactive compounds such as total chlorophyll, ascorbic acid, and phenolic compounds decreased with ripening, whereas total carotenoids increased due to chlorophyll degradation and carotenoid biosynthesis. Anthocyanin and total flavonoid levels increased in the final stages of ripening. Thus, the developmental stage directly influences the physicochemical and functional characteristics of S. purpurea fruit flours. This comprehensive analysis offers valuable insights into the drying kinetics of S. purpurea fruits and underscores the influence of maturation stages on the quality attributes of the resultant flours.