Palavras-chave: evapotranspiração, milho, lisímetro de pesagem. SANTOS, W. P.; SOBRINHO, J. E.; MEDEIROS, J. F.; MOURA, M. S. B.; NUNES, R. L. C.

The integration of research emphasizing sustainable development, employment, income generation and food security has been highlighted in the media. The objective of this research was to evaluate the agro-economic responsiveness of radish associations with cowpea in the presence of different amounts of roostertree, spatial arrangements and agricultural crops. The experimental design was a randomized block design with four replications, with treatments arranged in a 4 x 3 factorial scheme, where the first factor consisted of four amounts of C. procera incorporated in the soil (20, 35, 50 and 65 t ha-1 on a dry basis) and the second factor of three spatial arrangements (2:2, 3:3, and 4:4) in two cropping seasons. Radish samples were evaluated for plant height, dry mass of shoots, total and commercial productivity of roots, productivity of scrap roots, and dry mass of roots, while in cowpea, vegetation was assessed for length of green pods, number of pods per square meter, productivity and dry mass of green pods, number of green grains per pod, weight of 100 green grains, and yield and dry mass of green grains. The economic indicators of monetary advantage and modified monetary advantage were used in the evaluation of efficiency. A greater agro-economic responsiveness of the intercropping of radish and cowpea crops was obtained with the incorporation of 56.44 t ha-1 of C. procera. The spatial arrangements of 3:3 and 4:4 had better agronomic and economic responsiveness. The association between radish and cowpea is feasible when the crops are fertilized with C. procera.

-In the Brazilian state of Rio Grande do Norte, the significant planting of onions is relatively recent, with producers seeking alternative ways to reduce losses. As a result, it was aimed to evaluate the agronomic performance of onion hybrids in the town of Baraúna in the semi-arid region of Rio Grande do Norte. The experimental design was of randomised blocks with six replications. Treatments consisted of eight hybrids (Cronus F1, Predilata F1, Serena F1, Fortaleza F1, Mata Hari, Luana, Lambada, Don Victor) and a control cultivar (IPA 11). The following were evaluated: average plant height; average number of leaves; diameter of the pseudostem; productivity; average bulb weight; rate of survival; leaf-waxiness; cultivar cycle; commercial classification of the bulbs. The Serena F1 and Mata Hari cultivars are recommended for the northeast semi-arid region due to high productivity, early cycle and better bulb classification. The use of these cultivars may help, in the short term, to change cultivation of the onion in the state of Rio Grande do Norte.Key words: Allium cepa. Productivity. Precocity. Bulb classification. RESUMO -No estado do RioGrande do Norte o plantio de cebola de forma mais expressiva é relativamente recente, sendo que produtores então buscando alternativas como formas de diminuir os prejuízos. Em função disso, objetivouse avaliar o desempenho agronômico de híbridos de cebola na região semiárida no município de Baraúna -RN. O delineamento experimental foi o de blocos casualizados com seis repetições. Os tratamentos consistiram de oito híbridos (Cronus F1, Predileta F1, Serena F1, Fortaleza F1, Mata Hari, Luana, Lambada, Don Victor) e uma cultivar testemunha (IPA 11). Foi avaliada a altura média de plantas, o número médio de folhas, o diâmetro do pseudocaule, a produtividade, a massa média dos bulbos, o índice de sobrevivência, a cerosidade foliar, o ciclo das cultivares e a classificação comercial de bulbos. As cultivares Serena F1 e Mata Hari são recomendadas para a região semiárida nordestina em função da alta produtividade, ciclo precoce e melhor classificação dos bulbos. O emprego dessas cultivares poderá, em curto prazo, contribuir para mudar o panorama da cultura da cebola no Estado do Rio Grande do Norte. Palavras

ABSTRACT The objective of this work was to evaluate the effect of planting spatial arrangements between the cowpea and beet crops in intercropping and of cowpea population densities on the crop’s productivity and in the agro-economic efficiency of the association at two growing seasons. The experimental design was of randomised blocks with the treatments arranged in a 4 x 3 factorial scheme, in four replications. The first factor was constituted by three spatial arrangements between the component cultures (2:2, 3:3 and 4:4), formed by beet rows alternated with cowpea rows, while the second factor was constituted by the population densities of cowpea: 40, 60, 80 and 100% of the recommended population in single crop (RDSC). The production and its components were evaluated in the beet and cowpea. Apart from these characteristics, the following agro-economic indicators were also determined for each treatment: system productivity index (SPI), the land equivalent coefficient (LEC), and the monetary equivalent ratio (MER). The maximum production of commercial beet roots was obtained with 15.60 t ha-1 productivity at density of 61.82% of RDSC within the 4:4 arrangement, while the maximum yield of cowpea green grains of 2.23 t ha-1 was reached at density of 79.57% of RDSC within 2:2 spatial arrangement. The productivities of beet roots of extra A, extra AA and great types decreased with increasing cowpea population density, without any influence of the tested spatial arrangements. The maximum mean productivity of cowpea green pods of 1.74 t ha-1 was obtained at density of 87.47% of RDSC, reached within 2:2 spatial arrangement. The maximum economic efficiency of the cowpea-beet intercropping was obtained with MER of 1.11 at cowpea density of 100% of RDSC, irrespective of the spatial arrangement and growing season.

Avaliação agronômica do feijão-caupi em função do controle de invasoras com diferentes herbicidas e combinações

RESUMO O objetivo deste trabalho foi avaliar as habilidades competitiva e biológica do consórcio de beterraba com caupi-hortaliça, em função de quantidades de biomassa de flor-de-seda incorporada ao solo e de arranjos espaciais. O delineamento experimental utilizado foi o de blocos completos casualizados, em esquema fatorial 4 x 3, compreendendo a combinação de quatro quantidades de flor-de-seda incorporadas ao solo (20, 35, 50 e 65 t ha-1 de matéria seca) e três arranjos espaciais, entre fileiras de plantas, das culturas componentes do consórcio (2:2, 3:3 e 4:4). Foram avaliados os índices de competição: o de perda ou de ganho real de rendimento, o de superação e o coeficiente relativo populacional e de razão competitiva. Os índices de eficiência biológica avaliados foram: uso eficiente da terra, da beterraba e do caupi-hortaliça. A cultura do caupi-hortaliça apresentou maior ganho de produção e melhor capacidade de competição do que a cultura da beterraba, e os arranjos espaciais não influenciaram o desempenho produtivo das culturas. A maior viabilidade biológica do consórcio de beterraba com caupi-hortaliça foi obtida na quantidade de 65 t ha-1 de biomassa de flor-de-seda incorporada ao solo. Não houve influência dos arranjos espaciais na habilidade competitiva e na viabilidade agroeconômica do consórcio de beterraba com caupi-hortaliça.

One of the biggest challenges in the intercropping system of two crops is to obtain the optimal dose of green manure and the adequate population density of the crops. So, the objective of this work was to evaluate the performance of beet and arugula intercropping, influenced by green manuring with Merremia aegyptia and Calotropis procera and arugula population densities in two cultivation years, in semi-arid environment. The experimental design used was in randomized complete blocks, with the treatments arranged in a 4 x 4 factorial scheme, with 4 repetitions. The first factor of this scheme consisted of equitable amounts of M. aegyptia and C. procera biomass (20, 35, 50 and 65 t ha-1 on a dry basis) and the second factor, by arugula population densities (40, 60, 80 and 100% of the recommended density for single cropping, corresponding to 400, 600, 800 and 1,000 thousand arugula plants ha-1). The production and its components were evaluated on beet and arugula. In addition to these characteristics, the following agro-economic indicators were also determined for each treatment: system productivity index (SPI), land equivalent coefficient (LEC) and monetary equivalent ratio (MER). The greatest agro-economic advantages of the beet with arugula intercropping were achieved with a system productivity index (SPI) of 53.47 t ha-1, land equivalent coefficient (LEC) of 0.84 and a monetary equivalent ratio (MER) of 1.56, respectively, combining 65 t ha-1 of M. aegyptia and C. procera biomass with the arugula population density of 1,000 thousand plants ha-1. The maximum optimized commercial productivity of beetroots in the system intercropped with arugula was 23.20 t ha-1 using 65 t ha-1 of M. aegyptia and C. procera and in the arugula population density of 1,000 thousand plants ha-1, while the maximum arugula productivity intercropped with beet was 9.65 t ha-1, in the same combination of green manures amount and arugula population density.

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