Abstract Water is a resource for agriculture, urban and industrial activities. It is insufficient in the arid climate areas in the north east of Brazil. Saline water is as an alternative to the expansion of agricultural irrigation areas. Our objective was to assess the effect of irrigation with saline water and nitrogen fertilization on sunflower (Helianthus annuus L.) cv. EMBRAPA 122-V2000 growth. This study was carried out in a greenhouse at the Campina Grande Federal University, Paraiba, Brazil, between April and July 2012. The experimental design was completely random with three replications in a 5×5 factorial arrangement; salinity levels in irrigation water, with electrical conductivity (ECa) of 0.7, 1.7, 2.7, 3.7 and 4.7 dS m-1 (25 °C) and N doses of 50, 75, 100, 125 and 150 mg kg-1 as factors, in 75 experimental units. The variables evaluated during the growth cycle were: plant height, stem diameter, number of leaves, leaf area, flowering onset, maximum inflorescence opening, inner and external flower diameter, and chlorophyll content. The results with ECa of 0.7 dS m-1 linearly decreased. The salinity of the irrigation water and nitrogen fertilization interaction was not significant in the evaluated variables, except for the plant height 15 d after sowing. The flowering variables were delayed as the salinity of the irrigation water increased and chlorophyll content decreased, but increased with N. | Resumen El agua es un recurso para la agricultura, urbano e industrial y es insuficiente en zonas con clima semiárido en el nordeste de Brasil. El agua salina debe considerarse una alternativa para la expansión de las zonas agricolas con riego. El objetivo de este estudio fue evaluar el efecto del riego con agua salina y fertilización nitrogenada en el crecimiento del girasol (Helianthus annuus L.) cv. EMBRAPA 122-V2000. El estudio se desarrolló en un invernadero de la Universidad Federal de Campina Grande, Paraiba, Brasil, entre abril y julio de 2012. El diseño experimental fue totalmente al azar con tres repeticiones, en arreglo factorial 5×5; niveles de salinidad del agua de riego con conductividad eléctrica (ECa) de 0.7, 1.7, 2.7, 3.7 y 4.7 dS m-1 (25 °C) y dosis de N de 50, 75, 100, 125 y 150 mg kg-1, en 75 unidades experimentales. Las variables evaluadas durante el ciclo de crecimiento fueron: altura de la planta, diámetro del tallo, número de hojas, área foliar, inicio de floración, apertura máxima de la inflorescencia, diámetro interno y externo del capítulo floral, y contenido de clorofila. Los resultados con ECa de 0.7 dS m-1 decrecieron linealmente. La interacción salinidad del agua del riego y fertilización nitrogenada no fue significativa en las variables, excepto en la altura de la planta 15 d después de la siembra. Las variables de la floración se retardaron con el aumento de la salinidad del agua de riego y el contenido de clorofila disminuyó, pero aumentó con el N.

Não existem ainda estudos sobre a tolerância do tamarindeiro a salinidade da água de irrigação na produção de mudas do tipo pé-franco. O objetivo do trabalho foi avaliar os efeitos de concentrações salinas na irrigação, sobre o crescimento inicial de mudas tipo pé-franco de tamarindeiro (Tamarindus indica L.). Os tratamentos consistiram de soluções salinas de NaCl nas concentrações 1,5; 3,0; 4,5 e 6,0 dS m-1, sendo a testemunha (água de poço C.E. 0,4 dS m-1). O delineamento experimental utilizado foi blocos casualizados, contendo 5 tratamentos, sendo 4 repetições e 5 mudas por parcela. Aos noventa dias após a semeadura, foram avaliada a altura da muda; número de folhas, diâmetro de colo, matéria seca da parte aérea, da raiz e total. Observou-se que a medida que aumentam os níveis de salinidade, as características produção de matéria seca da parte aérea, das raízes e total das mudas de tamarindeiro tipo pé-franco foram afetadas, negativamente. As demais características não foram afetadas significativamente. Assim durante a fase de formação de mudas, o tamarindeiro não tolera a elevação das concentrações salinas na irrigação. | There are no studies on the tolerance of tamarind the salinity of irrigation water on seedling type rootstocks. The objective of this study was to evaluate the effects of salt concentrations in irrigation on the initial growth of seedling type rootstocks of tamarind. The treatments consisted of saline solutions of NaCl concentrations 1.5, 3.0, 4.5 and 6.0 dS m-1, and the control (well water EC 0.4 dS m-1). The experimental design was randomized blocks, containing 5 treatments, 4 replications and 5 plants per plot. Ninety days after sowing, were evaluated in high plant, number of leaves, stem diameter, dry weight of shoot and root. It was observed that with increasing levels of salinity, the characteristics of dry matter yield of shoot, root and total seedling tamarind type of rootstocks were affected negatively. The other characteristics were not significantly affected. So during the formation of seedlings, the tamarind does not tolerate the high salt concentrations in irrigation.