Honey is a substance that contains a variety of macro and micro minerals present in the range between 0.02-1.03%. The main objective of this study was to determine the concentration of elements inorganic in 15 honey samples collected in various regions of Maranhão (Northeast Brazil), using highly sensitive analytical techniques, such as inductively coupled plasma optical emission spectrometry (ICP-OES), in addition to applying multivariate statistical tools, such as Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) in the treatment of data. The method presented detection limits between 0.4 to 2.8 mg kg-1. Fifteen samples and 19 metals were analyzed, and two of these samples had high levels of lead, exceeding the limits allowed by Brazilian legislation. Thus, it can be concluded that the presence of potentially toxic metals in honey is an indication that the production areas may be contaminated by different external sources. The chemometric analysis of the data by PCA and HCA allowed to classify honey in two main groups: honey produced in urban areas and honey produced in rural areas with PCA explaining 73% of the data variance with the sum of the first 3 components.

Resumo Dados de experimentos de campo conduzidos em parreirais de uva de mesa da variedade Festival, em Petrolina-PE, no período de outubro/2009 a novembro/2010, foram usados para avaliar a influência da cobertura plástica sobre o microclima, produtividade e impacto econômico de parreirais. Foram estudados três tratamentos: sem cobertura (SC); com cobertura plástica posicionada a 50 cm acima do dossel (CP50); e com cobertura plástica posicionada a 100 cm acima do dossel (CP100). Os resultados indicaram que a maior oferta de fluxos radiativos na altura das bagas no tratamento CP100 contribuiu para uma maior produtividade, enquanto que o tratamento CP50 teve a menor oferta de fluxos radiativos na altura das bagas e uma produtividade bem menor. A produtividade obtida no tratamento CP100 superou em 11 t ha-1 àquela do tratamento SC e em 12,3 t ha-1 a do tratamento CP50. O tratamento CP100, também foi o que apresentou as menores quantidades de defeitos graves e leves, o que contribuiu para uma maior receita total. Em contra partida, o tratamento CP50 teve uma produtividade acentuadamente menor, o que representou prejuízos econômicos consideráveis.

Abstract Data from field experiments conducted in vineyards table grape variety of Festival in Petrolina-PE, from October/2009 to November/2010, were used to evaluate the influence of the plastic cover on productivity and economic profitability of the viticulture in the São Francisco River Valley. Three treatments were studied: uncovered canopy (UC), plastic cover placed at 50 cm above the canopy (PC50), and a plastic cover placed at 100 cm above the canopy (PC100). The results indicated that the increased supply of radiative fluxes at the height of the berries in the treatment PC100 contributed to higher productivity, while treatment PC50 had the lowest offer of irradiative fluxes at the height of berries and much lower productivity. The yield obtained in the treatment PC100 exceeded 11 t ha-1 and 12.3 t ha-1 to those of treatments at UC and PC50, respectively. Treatment PC100 also had the lowest amounts of defects of berries, which contributed to higher total revenue. By contrast, treatment PC50 had markedly lower productivity, which represented considerable economic losses.

A poda de ramas em plantas da família Cucurbitaceae é prática bastante controvertida e tem sido questionada por técnicos e produtores que buscam informações sobre a melhoria da produção de frutos, em pepineiro tutorado e cultivado a campo. Neste experimento, avaliou-se produtividade de frutos de três híbridos de pepino, com tutoramento vertical e diferentes tipos de poda. O experimento foi conduzido na área experimental da Empresa de Pesquisa Agropecuária de Minas Gerais em Oratórios-MG, de 09 a 12/2010. Utilizou-se o delineamento em blocos casualizados com quatro repetições, no esquema de parcelas subdivididas. Três híbridos de pepino [Aladim (salada), Natsuno Kagayaki (japonês) e Safira (caipira)] constituíram as parcelas e cinco tipos de poda das plantas, as subparcelas. O plantio foi feito por meio de mudas. A colheita iniciou-se aos 52 dias após a semeadura, quando foram avaliados número e massa da matéria fresca dos frutos comerciais e massa da matéria fresca das plantas. O híbrido de maior produção foi Natsuno Kagayaki (62,97 t/ha), enquanto os híbridos Safira e Aladim produziram em média 45,51 e 40,16 t/ha respectivamente. A massa fresca média de frutos não foi influenciada pelo tipo de poda e nem pelos híbridos. O número total de frutos e a produtividade de frutos comerciais foram menores na poda mais drástica, ou seja, quando se fez poda, capação e podas de hastes laterais. Nessa poda ocorreu também redução na massa de matéria fresca da parte aérea da planta. Os tipos de podas realizados não proporcionaram ganhos na produtividade de frutos de pepino, para os três grupos e híbridos avaliados, na região da Zona da Mata Mineira.

Branch pruning of plants of the Cucurbitaceae family is a very controversial practice. It has been questioned by technicians and farmers who search for information on how to improve fruit yield, especially for the field-grown staked cucumber plants. In this experiment, fruit yield of three cucumber hybrids with vertical staking and different methods of pruning were evaluated. The experiment, carried out at EPAMIG in Oratórios, Minas Gerais state, Brazil, from September to December 2010, was arranged in a randomized block design, with four replications in split plots. The plots were established by three cucumber hybrids [Aladim (salada), Natsuno Kagayaki (japanese) and Safira (caipira)] and the split-plots by five pruning methods. Seedlings were planted and the vertical staking system was applied. Harvesting initiated 52 days after sowing, when number of fruits and fresh mass of fruits and plants were evaluated. The hybrid Natsuno Kagayaki presented the highest yield (62.97 t/ha). Pruning did not influence number of fruits and fresh mass of fruits and plants. Cucumber fruit yield was not influenced by pruning method. In the Zona da Mata region of Minas Gerais, plant pruning does not provide gains in yield and fruit quality for the evaluated groups and hybrids of cucumber

The effects of increasing plant diversity on the population of the coffee leaf-miner Leucoptera coffeella (Guérin-Mèneville) were investigated in two organic coffee production systems. One system consisted of coffee intercropped with banana trees (shaded system) and the other one of coffee intercropped with pigeon pea (unshaded system). The increase in plant diversity on both systems was achieved via introduction of green manures such a perennial pea nut, sunn hemp and Brazilian lucerne. The population of L. coffeella, predation and parasitism of L. coffeella mines were biweekly evaluated during eight months. The increase in plant diversity on both systems did not affect the attack of L. coffeella on coffee leaves and the mine parasitism rate. However, there was a positive and significant relationship between increasing plant diversity and coffee leaf mine predation by wasps on unshaded coffee system and a negative relationship on shaded coffee system.