O Noni (Morinda citrifolia L.) é uma planta tolerante aos efeitos salinos e alcalinos dos solos e desenvolve-se em regiões de clima seco ou úmido. Apesar da adaptabilidade intercontinental, ainda são poucas as informações sobre sua tolerância aos sais no solo brasileiro. Baseado no exposto, objetivou-se com o presente trabalho avaliar os efeitos da água salina no crescimento inicial do Noni. Para isso, foi conduzido um experimento em vasos de polietileno com capacidade para 20 L, em Sobral, Ceará. O delineamento estatístico adotado foi em blocos ao acaso, disposto no esquema de parcelas subsubdivididas, com 5 repetições. As parcelas foram constituídas pelos ambientes de cultivo (céu aberto e telado), as subparcelas pelos níveis de salinidade da água de irrigação (CEa: 0,3;1,5; 3,0; 4,5 e 6,0 dS m-1) e as subsubparcelas foram representadas pela ausência e presença de matéria orgânica. Aos 110 dias após a aplicação dos tratamentos (DAT), avaliaram-se: altura, massa seca da parte aérea (MSPA), da raiz (MSR), total (MST) e área foliar (AF), e aos 90 (DAT) os teores foliares de solutos orgânicos. Todas as variáveis de crescimento estudadas foram afetadas negativamente pela salinidade, sendo que o efeito observado a céu aberto foi mais expressivo do que no ambiente telado. A matéria orgânica não teve efeito atenuante sobre os efeitos deletérios da salinidade em plantas de noni. O acúmulo de prolina mostrou-se um sinalizador de dano causado pelo estresse, visto que os maiores acúmulos ocorreram nas plantas que sofreram maiores reduções no crescimento.

Salinity is one of the main agricultural problems faced, and may negatively influence plant development. However, studies have shown that in protected environments and under the application of organic fertilizers, deleterious effects are mitigated. In this context, the objective of this study was to evaluate the effects of irrigation water salinity on mineral nutrition in noni plants grown in two environments and bovine manure application. The statistical design was a randomized block design arranged in split-split plot scheme, with five repetitions. The plots consisted of the cultivation environments (greenhouse and open field), the subplots formed by salinity levels of irrigation water (ECw: 0.3, 1.5, 3.0, 4.5 and 6.0 dS m-1), and the subsubplots were represented by the absence and presence of organic matter, with experimental unit consisting of three pots totaling 300 pots. The nitrogen, potassium, calcium, magnesium, sodium and chloride concentrations were determined in plant leaves. It was verified that the foliar concentrations of Ca2+, Mg2+, Na+ and Cl- and the ratio Na/K was increased with increasing salinity of the irrigation water, being the largest increments observed in the open field. Organic matter is not much relevant in attenuating the deleterious effects of irrigation water on the concentration of leaf nutrient in noni plants. The maintenance of lower values of Na/K ratio in the treatment with organic matter is a positive factor that can attenuate the effects of salt stress on cell metabolism.

The objective of this work was to evaluate the effect of the application of different doses of hydrogel and irrigation levels on the morphophysiological and productive behavior of a bell pepper cultivar, in a protected environment. Four doses of hydrogel (0.0, 0.6, 1.2, and, 2.4 g per plant) and four irrigation levels (50, 75, 100, and, 125%) were used, on the basis of the daily evapotranspiration of a bell pepper crop grown in a sandy soil. Height, stem diameter, and leaf area were measured at 70 and 100 days. At the end of the experiment, bell pepper yield and water use efficiency were estimated. Hydrogel associated with irrigation increases leaf area, productivity, and irrigation-water use efficiency. The applied water deficit (132.8 and 199.26 mm), associated with the hydrogel doses, does not affect the plants morphologically.

The influence of split nitrogen applied via fertigation on the culture of early-cycle BRS 323 sunflower was evaluated. The experiment was conducted at the Federal University of Ceará, Brazil, in a randomized block design, with five treatments and five repetitions. The treatments corresponded to the recommended N doses: 50; 25; 12.5; 6.25 and 3.2 kg ha^-1. At 55 days after sowing, the following variables were evaluated: thousand seed mass, productivity, seed oil content, head dry mass, leaf dry mass and leaf area as a function of the number of N applications via fertigation. Yield, seed oil content and head dry mass were influenced by N treatments at the 5% level, while thousand seed mass, leaf dry mass and leaf area were significant at 1%. The application of parceled nitrogen fertilization by fertigation can be recommended to sunflower producers, because it can increase the production of this crop, since the parceled application of N positively influences the behavior of the following variables: DMLeaf; Leaf area; 1000SM, PROD, SOC and MS Head.

: O presente estudo teve como objetivo os efeitos de cinco níveis de salinidade da água de irrigação (T₁ = testemunha= 0,27; T₂ = 1,5; T₃ = 2,5; T₄ = 3,5 e T₅ = 4,5 dS m^-1 ), sobre o crescimento inicial do maracujazeiro amarelo. O trabalho foi conduzido em condições de laboratório e campo (Telado Agrícola) no Instituto Federal de Educação, Ciência e Tecnologia do Ceará – Campus de Sobral. Utilizou-se o delineamento experimental em blocos casualizados, com quatro repetições, colocando-se 32 sementes por unidade experimental. As variáveis analisadas foram: altura das plantas (AP), número de folhas (NF), diâmetro do caule (DC), massa seca da parte aérea (MSPA) e massa seca da raiz (MSR). O maracujazeiro amarelo apresentou elevada sensibilidade aos sais, sendo que com exceção do diâmetro do caule, as demais variáveis avaliadas foram afetadas de maneira significativa pelo estresse salino a partir de 1,5 dSm^-1.