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The objective of this study was to evaluate the effect of a plant growth regulator (PGR; Stimulate®) on the yield and quality of zucchini fruits from plants of the cultivar Caserta-Italiana grown under different salinity levels of the irrigation water (SLIW). A randomized block design was used, in a 2 × 6 factorial arrangement consisted of two SLIW (0.5 and 5.0 dS m-1) and six PGR application modes: imbibition of seeds for 8 h in distilled water (PGR-T1; Control); imbibition of seeds for 8 h in PGR at 10 mL L-1 (PGR-T2); imbibition of seeds for 8 h in PGR at 10 mL L-1 plus foliar application at 10 mL L-1 at the flowering stage (PGR-T3); imbibition of seeds for 8 h in PGR at 10 mL L-1 plus two foliar applications at the flowering stage and at 20 and 30 days after sowing (PGR-T4); foliar application at 10 mL L-1 at the flowering stage (PGR-T5); and two foliar applications at 10 mL L-1 at 20 and 30 days after sowing (PGR-T6). The SLIW affected differently the variables of the zucchini crops evaluated. The PGR application to plants under no salt stress (0.5 dS m-1) increased the solid soluble concentration and biomass accumulation of zucchini fruits. The PGR application as seed treatment and foliar application at the flowering stage increased the fruit yield of zucchini plants irrigated with saline water. RESUMO Objetivou-se avaliar a utilização de bioestimulante (Stimulate®) na produtividade e na qualidade de frutos de abobrinha, cultivar Caserta Italiana, em condições salinas. O delineamento utilizado foi o de blocos casualizados, em esquema fatorial 2 × 6, sendo dois níveis de salinidade da água de irrigação (0,5 e 5,0 dS m-1) e seis estratégias de aplicação de bioestimulante [B1 - ausência de bioestimulante (embebição das sementes por 8 horas em água destilada); B2 - aplicado via tratamento de sementes (embebição por 8 h em bioestimulante); B3 - aplicação via semente (embebição por 8 horas em solução de bioestimulante 10 mL L-1) mais uma aplicação foliar no florescimento (10 mL L-1); B4 - aplicação via semente (embebição por 8 horas em solução de bioestimulante 10 mL L-1) mais duas aplicações via foliar no florescimento aos 20 e 30 dias após a semeadura; B5 - aplicação foliar (10 mL L-1) no florescimento; B6 - duas aplicações foliares (10 mL L-1), aos 20 e 30 dias após a semeadura]. A salinidade da água de irrigação afetou de forma diferenciada as variáveis analisadas na cultura da abobrinha. A aplicação do bioestimulante, na ausência do estresse salino, resultou no aumento do teor de sólidos solúveis e no acúmulo da biomassa de abobrinha. O bioestimulante aplicado via sementes e durante o florescimento aumentou a produtividade de frutos de abobrinha irrigada com água salina.

This study aimed to evaluate lettuce production in different pot volumes and different irrigation frequency under saline stress. The experiment was carried out at the Department of Environmental and Technological Sciences of the Federal Rural University of the Semi-Arid, in Mossoró, RN, Brazil. Randomized block experimental design was used in factorial scheme of 2 × 3 × 3, with 3 replicates. Treatments were consisted of 2 water’s salinity levels (0.5 and 2.0 dS m-1), 3 frequencies of irrigation (6, 9, and 12 daily events), and 3 different pots (0.5, 1.0, and 3.0 L). Data from parameters evaluated at harvest were submitted to variance analysis and means were compared. We verified that when the lower saline water (0.5 dS m-1) was used lettuce production increased when cultivated in pots of 3.0 L and submitted to 6 daily events of irrigation. When 3.0 dS m-1 water was used the best results were obtained in 0.5 L and nine daily events of irrigation. The combination of 0.5 L pot and six or nine daily events of irrigation better inhibited the damaging effects of salinity.