ABSTRACT. Bell peppers are sensitive to salinity; therefore, it is necessary to find alternatives to reduce saline stress. An experiment was conducted in a greenhouse at Federal Rural University of the Semi-Arid Region, in Mossoró, Rio Grande do Norte State, Brazil, to evaluate the effects of salinity and K+/Ca2+ ratios on bell pepper production. The experimental design consisted of randomized blocks in a 5 x 4 factorial scheme with four replicates, corresponding to five K+/Ca2+ ratios (F1 = 3.3/1, F2 = 2.8/1, F3 = 2.2/1, F4 = 1.8/1, and F5 = 1.5/1) and four salinity levels in the nutrient solution using NaCl (1.75, 3.25, 4.75, and 6.25 dS m-1). The following parameters were evaluated: the number of fruits (total, marketable and unmarketable), the mean weight of fruits (marketable and unmarketable), fruit production (total, marketable and percentage of marketable fruits) and a salinity tolerance index. Generally, nutrient solution enrichment with K+ or Ca2+ did not cause significant increments in bell pepper yield. The fertigation treatments F2, F3, and F5 led to a higher bell pepper tolerance to salinity, allowing waters with higher salt concentrations to be used without causing a reduction in the yield.

RESUMO A consorciação de culturas é um sistema de cultivo que envolve o cultivo de duas ou mais culturas na mesma área com diferentes ciclos e arquiteturas vegetativas. Uma das maneiras de aumentar a produtividade e a eficiência neste sistema de cultivo é através de adubação verde e considerando adequadamente as combinações de culturas, o tempo e a configuração de plantio das culturas componentes. Assim, o objetivo deste estudo foi avaliar o desempenho produtivo de sistemas consorciados de cenoura e alface em diferentes quantidades de biomassa de flor-de-seda incorporadas no solo e em diferentes arranjos espaciais. O estudo foi realizado na fazenda experimental Rafael Fernandes, RN, Brasil, no período de setembro de 2012 a janeiro de 2013, em um delineamento experimental de blocos completos casualizados, em esquema fatorial 4 x 3, com doze tratamentos e 3 repetições. Os tratamentos consistiram da combinação de quatro quantidades de biomassa de flor-de-seda incorporadas no solo (10, 25, 40 e 55 t ha-1 em base seca) com quatro arranjos espaciais predeterminados entre as culturas componentes (2:2, 3:3 e 4:4), que correspondem às fileiras de cenoura alternadas com as fileiras de alface. O desempenho agronômico do sistema de consórcio de cenoura e alface foi otimizado na quantidade de aproximadamente 46.36 t ha-1 de flor-de-seda incorporada no solo. Não houve influência dos arranjos espaciais sobre a eficiência agronômica do consórcio de cenoura e alface. O uso da flor-de-seda como adubo verde é agronomicamente viável em sistemas consorciados de cenoura e alface.

ABSTRACT Intercropping is a cropping system that involves cultivating two or more crops in the same area with different cycles and vegetative architectures. One of the ways to increase productivity and efficiency in this cropping system is through green manuring and by properly considering crop combinations, cultivation timing, and planting configuration of the component crops. Thus, the aim of this study was to evaluate the productive performance of carrot and lettuce intercropping systems under different amounts of rooster tree biomass incorporated into the soil and under different spatial arrangements. The study was conducted at the experimental farm Rafael Fernandes, RN, Brazil, in the period from September 2012 to January 2013, in an experimental design of randomized complete blocks in a 4 x 3 factorial scheme, with twelve treatments and 3 replicates. The treatments consisted of the combination of four rooster tree biomass amounts incorporated into the soil (10, 25, 40 and 55 t ha-1 on a dry basis) with three predetermined spatial arrangements between the component crops (2:2, 3:3 and 4:4), which correspond to the rows of carrot alternating with the rows of lettuce. The agronomic performance of the carrot and lettuce intercropping system was optimized in the amount of approximately 46.36 t ha-1 of rooster tree incorporated into the soil. There was no influence of the spatial arrangements on the agronomic efficiency of the carrot and lettuce intercropping. The use of rooster tree as green manure is agronomically viable in intercropped systems of carrot and lettuce.

A escolha das sementes é de fundamental importância para a obtenção de mudas de qualidade, principalmente quando são produzidas sob condições ambientais adversas. Este trabalho foi desenvolvido com o objetivo de avaliar a influencia da salinidade sobre o desenvolvimento de mudas de moringa provenientes de sementes localizadas em diferentes posições no fruto. O delineamento utilizado foi o inteiramente casualizado, com os tratamentos arranjados em esquema fatorial 3 x 4 e quatro repetições. Os tratamentos resultaram da combinação de três posições de sementes no fruto (basal, mediana e apical) com quatro níveis de salinidade da água de irrigação (0,5; 2,0; 3,5; e 5,0 dS m-1). Foram avaliadas as seguintes características de crescimento: altura (ALT), diâmetro do caule (DC), diâmetro da raiz principal (DRP), número de folhas (NF), área foliar (AF), massa seca da parte aérea (MSPA), massa seca do sistema radicular (MSR) e massa seca total (MST). Os dados foram submetidos à análise de variância pelo teste F e as médias, comparadas pelo teste de Tukey a 5% de probabilidade, para o efeito da posição da semente no fruto; e por análise de regressão, para os dados provenientes da salinidade. Houve interação significativa na maioria das características avaliadas. A salinidade da água de irrigação diminuiu em todas as variáveis. As mudas provenientes de sementes localizadas na porção basal dos frutos foram mais afetadas pela salinidade da água de irrigação.

Choosing seeds is crucial for obtaining good quality seedlings, especially when the seedlings are grown under adverse environmental conditions. This work was carried out to evaluate the influence of salinity on the development of moringa seedlings from seeds located at different positions in the pod. The design used in this study was a completely randomized design with treatments arranged in 3 x 4 factorial scheme, with four replications. The treatments resulted from a combination of three positions in the seed fruit (basal, median and apical) with four salinity levels of irrigation water (0.5, 2.0, 3.5 and 5.0 dS m-1). The growth characteristics evaluated were the following: height (ALT), stem diameter (AD), diameter of the root principal (DRP), number of leaves (NL), leaf area (LA), shoot dry mass (SDM), root dry mass (RDM) and total dry mass (MST). The data were submitted to analysis of variance by F test and means were compared by the Tukey test at 5% of probability for the effect of seed position in the fruits, and to regression analysis for data from the salinity. Interaction was significant for most traits. The salinity of irrigation water caused a reduction in all variables. Seedlings from seeds located in the basal portion of the fruits are more affected by salinity of irrigation water.