RESUMO: O jambu [Acmella oleracea (L.) R. K. Jansen] é uma hortaliça folhosa típica da região amazônica, sendo muito empregada na culinária, na medicina popular e nas indústrias de cosméticos e fármacos. Apesar de seu crescente uso, o jambu ainda carece de informações precisas quanto a sua forma de produção. Com base nisso, este trabalho teve como objetivo avaliar a influência do espaçamento e da densidade de plantas por cova de plantio no crescimento e produção desta hortaliça. O experimento foi conduzido na horta didática da Universidade Federal do Ceará, em Fortaleza, Ceará. Utilizou-se o delineamento experimental em blocos ao acaso, em esquema de parcela subdividida, com três repetições. A parcela foi constituída de dois espaçamentos: 0,20 × 0,20 m e 0,25 × 0,25 m, e a subparcela, de cinco densidades de plantas por cova de plantio: três, cinco, sete, nove e doze plantas. Avaliou-se comprimento da parte aérea, comprimento da raiz, número de folhas, área foliar, massas frescas da parte aérea e da raiz, massas secas da parte aérea e da raiz, produtividade de massa fresca e trocas gasosas. Não houve interação entre os fatores espaçamento e densidade de mudas transplantadas na cova de plantio. O espaçamento não interferiu nas variáveis estudadas para as plantas avaliadas individualmente, contudo a densidade de plantas na cova de plantio interferiu na produção, sendo em geral explicada pelo modelo linear decrescente para quase todos os parâmetros avaliados. O espaçamento de 0,2 × 0,2 m, associado a maior densidade de plantas por cova, doze plantas, foi o que possibilitou a maior produtividade de biomassa de jambu.

Dentre os fatores ambientais, a água pode ser considerada o de maior influência no processo germinativo. Neste trabalho, objetivou-se avaliar períodos de pré-embebição de sementes de melancia em água e seus efeitos em características de crescimento e desenvolvimento de plântulas. Os tratamentos constituíram-se de pré-embebição por: 0, 12, 24, 48 e 72 h. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições. Aos seis e 12 dias após a semeadura (DAS), cinco plantas por repetição foram coletadas, sendo avaliados: comprimento da raiz principal, parte aérea e total da planta; massas fresca e seca da raiz principal, da parte aérea e total da planta. A pré-embebição das sementes por 12 horas favoreceu o aumento na emergência aos 12 DAS. As plântulas obtidas a partir de sementes pré-embebidas por 48 e 72 h foram as que apresentaram maiores valores para as características de crescimento e desenvolvimento avaliadas.

Spatial planning of cultivation arrangements is essential to ensure the superiority of intercropping when compared with monocrop. Thus, the aim of this study was to evaluate the agronomic performance of arugula/nira intercropping in different cultivation arrangements. The experiment was carried out in a randomized block design, in a split plot scheme, the plots represented the cultivation arrangements and the subplots the production cycles (winter and spring). The arrangements were T1= arugula monoculture; T2= two rows of arugula alternating with three rows of nira (2R:3N); T3= two rows of arugula alternating with two rows of nira (2R:2N); T4= two rows of arugula alternating with one row of nira (2R:1N); T5= nira monoculture. Productive traits and agronomic performance indexes of the intercropping systems were evaluated. Single arugula cultivation and 2R:1N intercropping achieved similar productivity, 2R:1N intercropping showed the highest productive efficiency, with land-use efficiency of 1.16%, though arugula showed a relative contribution of 84.3% in production yield of the system. We concluded that 2R:1N intercropping can be used to optimize the use of productive inputs in arugula cultivation.

Intercropping affords an increase in productivity by optimising the area used, as well as maximising input use efficiency the financial return of intercroping systems was higher than that observed in the respective individual cultures. Here we show prominently that the financial return of the consortium systems was higher than that observed in the respective individual cultures. The aim of this study was to evaluate the agronomic parameters, biological and productive efficiency, and economic performance of arugula under a single and intercropped system. The study was conducted at the Teaching Garden of the Federal University of Ceará, Brazil, in a randomised block design, with four replications and seven treatments: T1 (single arugula), T2 (arugula intercropped with coriander), T3 (arugula intercropped with parsley), T4 (arugula intercropped with garlic chives), T5 (single coriander), T6 (single parsley) and T7 (single garlic chives). Phytotechnical evaluations were carried out. Biological efficiency was evaluated based on the following factors: land use efficiency index or land equivalent ratio (LER), relative contribution of the arugula crop to the LER (CRC), area time equivalent ratio (RAET) and system productivity index (IPS). For the economic analysis, the following were evaluated: operational production costs (OC; BRL ha-1), gross revenue (GR; BRL ha-1), gross profit (GP; BRL ha-1), rate of return (RR; %) and profitability index (PI;%). The system based on arugula intercropped with coriander showed the best agronomic performance and biological efficiency. Productivity and economic advantage under this intercropped system were also superior to the other treatments.

The aim of this study was to evaluate the competitive ability and physiological aspects of arugula intercropped with different aromatic condiment species. The study was carried out at the Teaching Garden of the Federal University of Ceará, Brazil. A randomised complete block design was used, with four replications and seven treatments: T1 (single arugula), T2 (arugula intercropped with coriander), T3 (arugula and parsley), T4 (arugula and garlic chives), T5 (single coriander), T6 (parsley) and T7 (garlic chives). A physiological evaluation was made of the arugula only. Competitive ability was obtained by calculating the aggressivity index, simplified aggressivity, competitive ratio and compensation ratio. The leaf area index and specific leaf area were calculated. No difference was seen between the treatments with arugula for the physiological factors net photosynthesis, stomatal conductance, rate of transpiration and instant carboxylation efficiency under evaluation within each crop cycle, but there was a difference between the two cycles. The coriander showed the highest aggressivity index and competitive ratio, and was considered more competitive than the arugula, with a higher compensation ratio. As an intercrop, the arugula showed greater competitive ability than the parsley and garlic chives. The greatest leaf area and leaf area index in the arugula plants were seen when intercropped with coriander.