ABSTRACT Little is understood about the nutritional status of manganese (Mn) in oil palm (Elaeis guineensis Jacq.), further research is needed to provide technological support for greater productivity, especially on the dynamics of accumulation, recycling, immobilization and export. Thus, the objective of this work was to evaluate the dynamics of accumulation, immobilization, recycling, exportation and the efficiency of Mn use in oil palm plants at different ages. The experiment was carried out in a completely randomized design, with seven treatments (plant age: 2, 3, 4, 5, 6, 7, and 8 years of planting) and four replicates. The leaflets and male inflorescence were, the vegetative and reproductive organs with the highest Mn concentration, respectively. The accumulation of this nutrient in the tree crown predominated in the stipe through all years. The bunch exported the highest amount of Mn, especially in older plants. The oil palm immobilizes and recycles, more than exports, a large amount of Mn. The Mn use efficiency is increased as a function of the age of the crops in all the oil palm organs. In conclusion, the nutritional demand of oil palm is altered as a function of age, altering the dynamics of immobilization, recycling and exportation of Mn.

Abstract Malpighia emarginata D.C is an important crop of Brazil and significant source of antioxidant active compounds with notable health effects. The purpose of this work was to study three varieties of acerola (Malpighia emarginata D.C) at green unripe stage of maturity from the São Francisco Valley of Northeast Brazil. The fruits were evaluated for physico-chemical composition, bioactive compounds, through spectrophotometric analysis and liquid chromatography, as well as the profile of macro and micro minerals and antioxidant capacity. The fruits presented satisfactory results in physico-chemical quality parameters. HPLC-DAD phenolic profile analysis identified kaempferol-3-glucoside (32.68 mg/100 g), p-coumaric acid (28.87 mg/100 g) and isorhamnetin (11.41 mg/100 g) as the major compounds, mainly in the variety of Flor Branca (FB). The results obtained from the profiles of sugars and organic acids were similar among the varieties. The minerals were excellent sources of the elements of K, Ca, Mg and Mn. Moreover, FB variety represents higher antioxidant capacity in ABTS·+ (8613.54 μM Trolox/g) and ORAC (2454.42 μM Trolox/g). Thus, the results show the potential to be applied for variety selection and utilization programs based on their specific nutritive characters, contributing to the development of new products.

Resumo O açaizeiro é a principal palmeira cultivada na Amazônia brasileira, e a diagnose nutricional torna-se uma ferramenta essencial ao manejo da cultura. O objetivo deste trabalho foi determinar a folha padrão para a diagnose nutricional do açaizeiro por meio da avaliação dos teores foliares e da utilização de dois métodos de análises estatísticas, tradicional (univariada) e multivariada. O estudo foi conduzido no munícipio de Belém - PA, com oito tratamentos: posições filotáxicas das folhas (folhas 2 a 9), em delineamento inteiramente casualizado. A concentração foliar dos nutrientes (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn) foi determinada para a realização das análises descritivas, de variância, correlação e análise de componentes principais. As folhas novas apresentaram maiores concentrações de N, P, K, Mg, S, Cu e Zn, ao passo que, nas folhas mais velhas, houve maiores concentrações de Ca, B, Fe e Mn. As folhas que apresentaram menor variação nas concentrações dos nutrientes foram de 2 a 5. A análise de PCA indicou interação de cargas positivas de N-P e Cu-Mg e interação de cargas negativas de Ca-Mn. O índice de distribuição dos nutrientes indicou a folha 5 com o menor valor de carga fatorial. Nesse sentido, a folha número 5 é a mais indicada para a diagnose nutricional de plantas de açaizeiro por meio de amostragem de 25 plantas.

Abstract Assai palm is the main palm tree grown in the Brazilian Amazon. Nutritional diagnosis has become an essential tool in management of the crop. The aim of this study was to determine the standard leaf for nutritional diagnosis of the assai palm tree through evaluation of leaf nutrient content and use of two methods of statistical analyses: traditional (univariate) and multivariate. The study was conducted in the municipality of Belém, with eight treatments: the phyllotaxic positions of the leaves (number 2 to 9), in a completely randomized design. The leaf concentration of nutrients (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn) was determined for performing descriptive analyses, analyses of variance, correlation analysis, and principal component analysis (PCA). Young leaves had greater concentrations of N, P, K, Mg, S, Cu, and Zn, whereas in the older leaves, there were greater concentrations of Ca, B, Fe, and Mn. The leaves that exhibited less variation in nutrient concentrations were from 2 to 5. PCA analysis indicated interaction of positive loads of N-P and Cu-Mg and interaction of negative loads of Ca-Mn. The index of nutrient distribution indicated leaf number 5 as having the lowest factor loading value. Thus, leaf number 5 is most recommended for nutritional diagnosis of assai palm plants through sampling of 25 plants.

ABSTRACT The generation of sewage sludge and the concern with their fate has greatly increased. The objective of this study was to assess the effects of using in natura (SS) or composted sewage sludge (SSC) in comparison with mineral fertilizer (MF) application and a control (CT) treatment on the nutritional status of Guanandi (Calophyllum brasiliense Cambess.) seedlings in a typical Red Oxisol in Brazil. The leaf-level nutritional responses of the Guanandi seedlings to these three different fertilizers and the control were evaluated at 90 and 180 days after planting. Nutritional data of leaf variables were compared between the treatments by means of one-way analysis of variance using the F test and a pair-wise comparison of means done by Tukey’s test. The seedlings that received SS or SSC showed deficiencies in Ca, Mg, and Mn, which were confirmed by a visual diagnosis of their leaf symptoms. However, at 180 days after planting there were significant differences (p < 0.05) for K that was greater for MF, SS and SSC than CT, Mg, with SSC larger than SS, and for S that was greater with SS and SSC uses relative to MF. The results highlight the potential for using SS and SSC, after adding KCl and lime, although the Guanandi was highly demanding of Ca, Mg, and Mn. However, they were able to nutritionally supply seedlings, although the short-term cannot be conclusive as regards the exclusive use of them in place of mineral fertilizers.

Resumo A bananicultura possui destaque na produção agrícola brasileira. Este destaque é alcançado devido ao uso de tecnologias de cultivo e de adubação adequada feita através de recomendações de avaliação de análises foliares. Objetivou-se neste estudo determinar a sazonalidade do estado nutricional da folha diagnóstica, durante o desenvolvimento do cacho da bananeira. Os experimentos foram conduzidos no município de Sete Barras-SP, com as cultivares ‘Grande Naine’ e ‘Prata’, no verão e no inverno. Avaliou-se a influência da coleta da folha diagnóstica nas estações, em seis épocas, durante o desenvolvimento do cacho, e comparou-se com a amostragem-padrão. Os valores foram submetidos à análise de variância, e, quando o F foi significativo realizou-se comparação de médias. As estações de amostragem e os estádios de coleta influenciaram o comportamento dos nutrientes na folha diagnóstica de ambas as variedades, com exceções para o Mg e o Mn. Os teores médios dos nutrientes durante os estádios de coleta não apresentaram diferença entre o 1º, 2º, 3º e 4º (padrão). Assim, para as bananeiras ‘Prata’ e ‘Grande Naine’, cultivadas no Vale do Ribeira, não há alteração significativa no teor foliar de nutrientes entre os estádios 1o a 4o, possibilitando a ampliação de coleta para análise de tecido foliar.

Abstract Banana farming has an important position in Brazilian agricultural production. This position was earned due to the use of cultivation technologies and adequate fertilization made through recommendations of evaluation of foliar analyzes. The objective of this study was to determine the seasonality of the nutritional status of the diagnostic leaf during the development of banana tree. The experiments took place in the city of Sete Barras / SP, with cultivars such as Grande naine and Prata, on summer and winter. It was evaluated the influence of the collection of the diagnostic leaf in the stations, in six seasons during the development of the banana bunch and it was compared with the standard sampling. The values were submitted to analysis of variance, and when the F was significant, a comparison of means was performed. The sampling stations and the collection stages influence the nutrient behavior in the diagnostic leaf of both varieties, with exceptions for Mg and Mn. The average levels of nutrients during the collection stages showed no difference among the 1st, 2nd, 3rd and 4th (standard). Even for the ‘Prata’ and Grande Naine banana plants cultivated in the Ribeira Valley, there is no significant alteration in the nutrient content of the foliage among the 1st to 4th stages, allowing an increasing of collection for foliar tissue analysis.

RESUMO O objetivo deste estudo foi comparar flushings à base de milho (FLU), ácido linoleico alto (FAL), e tratamento controle (não suplementado, CON);dois grupos genéticos: Morada Nova (MN) e Somalis Brasileiro (SB), sobre desempenho de ovelhas e cordeiros. Foram suplementadas 156 ovelhas não prenhes três semanas antes e após a estação de monta. Tanto FLU quanto FAL aumentaram o escore de condição corporal (ECC) de ovelhas no início da estação de monta e no parto, comparado ao CON. Ovelhas da raça SB tiveram maior peso no final da suplementação, e ECC, tanto no início da suplementação, quanto ao parto comparado ao MN. Da mesma forma, ovelhas com três cordeiros por nascimento tiveram ECC maior no início da suplementação. Elas também tiveram maiores pesos tanto no início da estação como no parto. Tanto FLU como FAL aumentaram o peso do cordeiro de 56 até 105 dias de idade comparadoao CON. Ovelhas SB diminuíram a prolificidade e produziram menor peso total de cordeiros ao parto, porém maior peso totalapós 84 e 105 dias comparado às ovelhas MN. O peso totaldecordeiros ao nascimento foi maior para ovelhas com gestação tripla, seguido por dupla, e simples. Em conclusão, a suplementação com ácido linoleico e milho aumentam o escore da condição corporal de ovelhas desde a estação de monta até o parto e a performance do cordeiro após 56 dias de idade. Embora ovelhas Morada Nova tenham aumentado a prolificidade, seus cordeiros ficaram mais leves apósos 84 dias de idade.

SUMMARY The objective of this study was to compare the corn-based (FLU), high linoleic acid flushings(LAF), and a control treatment (un supplemented, CON); two genetic groups:Morada Nova (MN) and Brazilian Somalis (BS), on the productive and reproductive performance of ewes and their lambs. A total of 156 non-pregnant ewes were supplemented three weeks before and after the breeding season. Supplementation with either FLU or LAF increased ewe body condition score (BCS) at the beginning of the breeding season and at lambing compared to CON. The BS ewes had greater body weights at the supplementation end, and BCS both at the supplementation start, and at lambing compared to MN. Similarly, ewes with three lambs per birth had greater BCS at the beginning of supplementation. They also had greater weights at the beginning of the breeding season and at lambing. Both FLU and LAF increased total lamb weight from 56 to 105 days of age compared to CON.The BS ewes had decreased prolificity and produced lower total weight of lambs at lambing, but greater 84 and 105 days after birth compared to MN. Total lambweight at birth was greater for ewes that lambed three, followed by two and then one lamb per birth. In conclusion, the high linoleic acid and high corn supplementation increase body condition score of ewes form breeding season to lambing and enhance lamb performance after 56 days of age. Although Morada Nova ewes increased prolificacy, their lambs were lighter after they reached 84 days of age.

ABSTRACT: Vale do Rio Doce shoot dieback (VRDSD) is an anomaly whose cause seems to be associated with hypoxic conditions and their consequences (excess Mn and Fe) triggered by elevation of the water table in areas with poor drainage. Different plants have distinct survival strategies under this form of stress. The objective of this study was to understand the physiological responses involved in the differential tolerance of eucalyptus clones to VRDSD and their relationship to hypoxia and excess Mn. A hydroponic experiment was carried out using a 2 × 2 × 2 factorial arrangement, two eucalyptus clones with different levels of tolerance to VRDSD (sensitive Urograndis hybrid - 1213; and the tolerant Rio Claro hybrid - Eucalyptus grandis x unknown - 2719), two concentrations of O2 (8 and 4 mg L-1), and two Mn concentrations (1.39 and 300 mg L-1) in a randomized block design (RBD) with three replicates. Forty-day-old clones were maintained in Clark nutrient solution for 30 days. After this period, the treatments were applied for 11 days. Plant gaseous exchange shoot and root production, and the quantity of enzymes related to oxidative stress in leaves and roots were evaluated. In the tolerant clone, reactive oxygen species (ROS) were produced under hypoxic conditions, accompanied by reduction in production of dry matter, malondialdehyde (MDA), and in activity of the enzyme alcohol dehydrogenase (ADH). However, this clone had greater production of superoxide dismutase (SOD) under these conditions, an enzyme responsible for detoxification of ROS, which acts as part of the Low Oxygen Quiescence Syndrome (LOQS). In contrast, sensitive clones did not exhibit expressive reductions in growth or changes in the leaf/root ratio. These clones formed large quantities of adventitious roots and had high levels of MDA and ADH and low levels of SOD. Therefore, sensitive clones appear not to be prepared for detoxification of ROS and other toxic metabolites, but rather adopt morphological escape mechanisms, the Low Oxygen Escape Syndrome (LOES), in response to hypoxia. Thus, the period of soil waterlogging may cause the death of large numbers of roots in sensitive clones, limiting their ability to absorb water and nutrients and culminating in the death of these plants. Excess Mn seems to aggravate the damage caused by hypoxia, but it is not the causal agent of VRDSD.

RESUMO No nordeste brasileiro, a bananicultura é praticada em locais onde há solos de profundidade variável. A dinâmica da água em solos mais profundos pode alterar minerais herdados diretamente da rocha e aumentar a disponibilidade de nutrientes. Neste estudo, objetivou-se avaliar o teor de nutrientes em Cambissolos raso e profundo, bem como o estado nutricional e a produtividade de bananeiras cultivadas nesses solos. Para a fertilidade do solo, foi utilizado o delineamento em parcelas subdivididas com dois tratamentos nas parcelas principais (solos raso e profundo) e seis tratamentos nas subparcelas (profundidades de coleta: 0 – 10, 10 – 20, 20 – 30, 30 – 40, 40 – 50 e 50 – 60 cm). Para avaliar o estado nutricional e a produtividade da cultura, foram considerados dois fatores de tratamento (solos raso e profundo) e 30 repetições. Foram determinadas as concentrações de macro e micronutrientes no solo e no tecido vegetal, outros atributos químicos do solo para avaliação da fertilidade e a produção de frutos. O solo profundo apresentou maiores valores de fósforo (P), potássio (K), sódio (Na), cobre (Cu), ferro (Fe), manganês (Mn), acidez potencial (H + Al), matéria orgânica (MO) e porcentagem de sódio trocável (PST). Teores de MO, valores de soma de bases (SB), saturação por bases (V%), Fe e Mn foram maiores na superfície dos solos. O estado nutricional das bananeiras foi favorecido no solo profundo, principalmente quanto às concentrações de nitrogênio (N), P, K, boro (B), Cu e Mn. Isso levou ao maior peso de cachos e à maior produtividade no solo mais profundo.

ABSTRACT In the Brazilian Northeastern region, banana cropping occurs in sites where there are soils presenting variable depths. The water dynamics in deeper soils may change minerals directly inherited from rock and increase nutrients availability. In this study, the aim was to evaluate the nutrient contents in shallow and deep Cambisols, as well as the nutritional status and yield of banana plants cropped in these soils. In order to study soil fertility, it was used the split plot design with two treatments in the main plots (shallow and deep soils) and six treatments in the subplots (soil sampling depths: 0 – 10, 10 – 20, 20 – 30, 30 – 40, 40 – 50 and 50 – 60 cm). In order to evaluate the nutritional status and crop yield, two treatment factors were assumed (shallow and deep soils) and 30 replicates. The concentrations of macro and micronutrients in both soil and plant tissue were determined, as well as other chemical attributes of soil for fertility evaluation, and fruit yield. The deep soil presented higher values of phosphorus (P), potassium (K), sodium (Na), copper (Cu), iron (Fe), manganese (Mn), potential acidity (H + Al), organic matter (OM) and exchangeable sodium percentage (PST). Organic matter, sum of bases (SB), bases saturation (V%), Fe, and Mn were higher in the soil surface. The nutritional status of banana plants was favored in the deep soil, mainly regarding contents of nitrogen (N), P, K, boron (B), Cu, and Mn. It resulted in higher weight of bunches and higher yield in the deeper soil.

Green manures have been used as biomass producers and suppliers of nutrients and keep the soil productive potential in tropical regions. The objective of this study was to evaluate the production of dry biomass and nutrient concentration and accumulation in plants of green manure in two cropping systems, without associating and associated with millet and its influence on the nutritional status of the bean (Phaseolus vulgaris L.) in succession in agroecological production. Four legumes (Canavalia ensiformis Adans; Cajanus cajan (L.) Millsp.; Crotalaria juncea L.; Mucuna pruriens (L.) DC) and one grass (Pennisetum glaucum L.) as association plant, were evaluated. A randomized block design was used, with eight treatments and four repetitions. The green manure plants were cut and left on the ground at 60 days after planting and bean was planted 20 days after cutting the manure plants. The evaluated variables were dried biomass production, nutrient content of green manure and nutrient content in leaves of beans in succession. The production of dry biomass of green manure was higher than 9.00 t ha-1. Mucuna stood out with the greatest tenors of N, Ca, Mg, pork beans with the highest tenors of K, Cu, Mn. The greatest accumulation of P, K and Ca nutrients was in pigeon pea. The highest values of N and Mg were obtained in mucuna. Higher C / N relation was obtained in crotalaria.

Los abonos verdes han sido usados como productores de biomasa y suministradores de nutrientes y mantienen el potencial productivo del suelo en regiones tropicales. El objetivo del presente estudio fue evaluar la producción de biomasa seca y la concentración y acumulación de nutrientes en plantas de abonos verdes, en dos sistemas de cultivo, sin asociar y asociadas con mijo y su influencia en el estado nutricional del frijol (Phaseolus vulgaris L.) en sucesión en producción agroecológica. Fueron evaluadas cuatro leguminosas (Canavalia ensiformis Adans; Cajanus cajan (L.) Millsp.; Crotalaria juncea L.; Mucuna pruriens (L.) DC ) y una gramínea (Pennisetum glaucum L.), utilizada para la asociación. En el experimento se utilizó un diseño de bloques al azar, con ocho tratamientos y cuatro repeticiones. Las plantas de abonos verdes fueron cortadas y dejadas en el suelo a los 60 días después de sembradas y el frijol fue sembrado a los 20 días después del corte de las plantas. Las variables evaluadas fueron, la producción y el contenido de nutrientes en la biomasa seca (BS) de los abonos verdes y el contenido de nutrientes en las hojas del frijol en sucesión. La producción de biomasa seca de los abonos verdes fue superior a 9,00 t ha-1. Se destacaron mucuna con los mayores tenores de N, Ca, Mg y canavalia con los mayores tenores de K, Cu, Mn. La mayor acumulación de los nutrientes P, K y Ca se produjo en Cajanus. En mucuna se obtuvieron los mayores valores de N y Mg. La mayor relación C/N la alcanzó crotalaria.

Plântulas de orquídeas cultivadas in vitro respondem de forma distinta aos vários meios de cultura empregados nessa técnica. Este trabalho comparou o meio nutritivo Knudson C, utilizado no cultivo de orquídeas, com o denominado MN e outros dois meios preparados com fertilizantes Peters®: NPK 10-30-20 + micronutrientes e NPK 30-10-10 + micronutrientes para o cultivo in vitro de plântulas do híbrido Etibaia (Cattleya walkeriana x C. loddigesii), com seis meses de idade, germinadas sobre o meio Knudson C. Os três últimos meios foram testados com as seguintes doses de sais: 0,25; 0,50; 1,00; 1,75; e 2,25 g L-1, e o meio Knudson C, 2,0 g L-1. A todos os meios adicionaram-se 20 g L-1 de sacarose, solidificado com 10 g L-1 de ágar, e o pH foi ajustado a 5,7. Aos meios MN e Peters® foram acrescentados 2 g L-1 de carvão ativado e 200 ml L-1 de água de coco. Foram utilizados frascos de vidro de 320 mL contendo 35 mL de meio nutritivo, e o experimento foi mantido em sala de crescimento a 27 ± 2 ºC, 16/8 h luz/escuro e irrdiância de 48 µmol m-2s-1. Melhores respostas para produção de matéria fresca foram obtidas com os fertilizantes NPK, em comparação com os meios Knudson C e MN. A produção de matéria fresca aumentou linearmente com o aumento da dose de nutrientes nos meios MN e nos dois NPK. As plântulas de orquídea cultivadas em meio Knudson C apresentaram os menores valores para as variáveis avaliadas.

Orchid seedlings grown in vitro respond differently to the different culture media used for this technique. This study compares the traditional Knudson (KC) medium used in orchid in vitro cultivation with a new medium formulation based on the KC medium with modifications, which was named Novais medium (NM), and two other media prepared with NPK fertilizer in the formulations 10-30-20 + micronutrients and 30-10-10 + micronutrients. The media were tested for the in vitro growth of six-month-old orchid seedlings derived from the cross Cattleya walkeriana x Cattleya loddigesii 'Etibaia' and germinated in Knudson C medium. The KC medium was tested in the concentration of 2.0 g L-1, and the other three media were tested in the concentrations of 0.25; 0.50; 1.00; 1.75; and 2.25 g L-1. All the media were added with 20 g L1 of sucrose, solidified with 10 g L-1 agar and pH adjusted to 5.7. NM and Peters® media were added with 2 g L-1 of activated charcoal and 200 ml L-1 of coconut water. The seedlings were cultured in 320 mL glass jars containing 35 mL of medium. The experiment was maintained in a growth room at 27±2 ºC, 16/8 h photoperiod with 48 ì mol m-2 s-1 irradiance. The best responses for production of fresh matter were obtained using NPK fertilizers, in comparison with KC and NM medium. The fresh matter production increased linearly with increasing nutrients doses in both MN and KC media. The orchid seedlings grown in Knudson medium had the lowest means for the variables evaluated.

As rochas basálticas possuem composição rica em elementos químicos considerados nutrientes às plantas, o que a torna apta para o uso agrícola, melhorando a fertilidade dos solos. Objetivou-se com esse trabalho avaliar o efeito de doses de basalto moído nos teores de alguns nutrientes no solo. Foi utilizado um Latossolo Amarelo ácido e de baixa CTC, formação geológica Boa Vista, estado de Roraima. A rocha basáltica da formação Apoteri foi coletada na pedreira da serra de Nova Olinda, Boa Vista. Os tratamentos consistiram da incorporação e incubação de oito doses do pó da rocha (0; 0,85; 1,70; 3,35; 5,03; 10,05; 20,40 e 40,80 g kg-1, correspondente a 0; 2,0; 4,0; 8,0; 12,0; 24,0; 48,0 e 96 t ha-1). O delineamento experimental foi inteiramente casualizado com oito tratamentos e três repetições. Após a incorporação do basalto moído ao solo e por um período 180 dias de incubação, o solo foi analisado quanto aos teores de Ca2+, Mg2+ e Al3+ trocáveis, acidez potencial (H+Al), teores disponíveis de Zn, Fe, Cu e Mn e valores de pH em H2O e em KCl. A dose de 20,40 g kg-1 de basalto proporcionou a máxima redução da acidez ativa, com pH aumentando de 4,8 para 5,5. Os teores de Ca2+ e Mg2+ trocáveis aumentaram, porém proporcionaram baixos incrementos desses cátions no solo. As doses de basalto apresentaram alta eficiência para a neutralização da acidez potencial. A adição do basalto moído proporcionou incremento nos teores de Zn, Fe e Cu no solo com o tempo de incubação.

Basaltic rocks have chemical and mineralogical composition that allows its agricultural application due to its capability of improving soil fertility. The aim in this work was to evaluate the effect of levels of finely crushed basalt rock in soil chemical conditioning. A dystrophic Yellow Latosol from pre-weathered Boa Vista Formation was used. The rock of the Apoteri formation was collected in the mine of Nova Olinda near Boa Vista. The treatments consisted of the incorporation and incubation of eight rock powder levels (0; 0.85; 1.70; 3.35; 5.03; 10.05; 20.40 and 40.80 g kg-1). The experimental design was entirely randomly with eight treatments and three replicates. After the incorporation of the rushed rock powder for a period 180 days of soil incubation, the soil was analyzed and determined the values of Ca2+, Mg2+, pH in H2O, pH in KCl, Al3+, H+ Al, Zn, Fe, Cu and Mn. The level of 20.40 g kg-1 of basalt provided the maxim reduction of the active acidity, varying from 4.8 to 5.5. Concentrations of exchangeable Ca2+ and Mg2+ increased, but their increments in the soil solution was small. Basalt levels presented high efficiency for neutralization of the potential acidity. Amendments with crushed rock increased extractable amounts of Zn, Fe and Cu in soil, after incubation.

O aumento da atividade turística em áreas costeiras nas últimas décadas faz necessária a adoção de estratégias de manejo para reduzir os impactos gerados às comunidades de costões rochosos. A região costeira do sudeste brasileiro possui bons exemplos de degradação causada pelo turismo e desenvolvimento industrial. Dentre os diferentes distúrbios causados pela visitação, o pisoteio têm sido estudado de forma intensa e pode representar uma fonte significativa de impactos para as comunidades da zona entre-marés. Neste projeto, foi aplicado um desenho de blocos randômicos para se avaliar experimentalmente os efeitos de duas intensidades de pisoteio na riqueza, diversidade, densidade, recobrimento e biomassa da fauna de um costão situado na praia do Obuseiro, no município do Guarujá, São Paulo, Brasil. Os blocos foram alocados em dois povoamentos diferentes, dominados respectivamente por Chthamalus bisinuatus (Cirripedia) e Isognomon bicolor (Bivalvia). O pisoteio foi aplicado durante três meses, simulando a temporada de férias no Brasil, e os blocos foram monitorados nos nove meses seguintes. Os resultados indicaram que Chthamalus bisinuatus é vulnerável aos impactos do pisoteio. Os índices de riqueza, diversidade e turnover apresentaram uma tendência ao aumento nas áreas pisoteadas quatro meses após o término do pisoteio. No geral, os resultados concordam com estudos anteriores e sugerem que mesmo baixas intensidades do distúrbio podem causar impacto às comunidades bentônicas. Estratégias de manejo devem envolver o isolamento de áreas sensíveis, a construção de passarelas, a educação dos visitantes e o monitoramento das comunidades impactadas. No Brasil, a realização de maior quantidade de estudos experimentais é necessária para a melhor compreensão dos impactos do pisoteio nas comunidades de costões rochosos.

Increased tourist activity in coastal regions demands management strategies to reduce impacts on rocky shores. The highly populated coastal areas in southeastern Brazil are an example of degradation caused by development of industry and tourism. Among different shore impacts, trampling has been intensively studied, and may represent a significant source of stress for intertidal fauna. A randomised blocks design was applied to experimentally study the effects of two different trampling intensities on richness, diversity, density and biomass of the rocky shore fauna of Obuseiro beach, Guarujá, southeastern Brazil. Blocks were distributed in two portions of the intertidal zone, dominated respectively by Chthamalus bisinuatus (Cirripedia) and Isognomon bicolor (Bivalvia). Blocks were trampled over three months, simulating the vacation period in Brazil and were monitored for the following nine months. Results indicate that Chthamalus bisinuatus is vulnerable to trampling impacts. Richness, diversity and turn-over index tended to be higher in trampled plots four months after trampling ceased. In general, results agree with previous trampling studies, suggesting that even low intensities of trampling may cause some impact on intertidal communities. Management strategies should include isolation of sensitive areas, construction of boardwalks, visitor education and monitoring programmes. In Brazil, additional data obtained from experimental studies are necessary in order to achieve a better understanding of trampling impacts on rocky shore communities.

A fonte de N fornecido às culturas influencia algumas propriedades do solo como o pH, causando efeitos indiretos na disponibilidade e, consequentemente na absorção de nutrientes pela planta. Em relação ao Mn, que pode influenciar na susceptibilidade de plantas a doenças, pode haver alterações até mesmo nas relações patógeno-hospedeiro. O objetivo deste trabalho foi avaliar o efeito de duas fontes de N e cinco doses de Mn na severidade da mancha-marrom em plantas de trigo, bem como na produção de matéria seca da parte aérea e raízes, a absorção desses nutrientes pelas plantas e a disponibilidade do Mn no solo. O experimento foi instalado em casa de vegetação e os tratamentos dispostos em um esquema fatorial (2 × 5), sendo duas fontes de N (amoniacal e nítrica) e cinco doses de Mn (0; 2,5; 5,0; 10,0 e 20,0 mg dm-3), em delineamento de blocos casualizados, com quatro repetições. Foram utilizadas amostras de um Latossolo Vermelho distrófico em vasos contendo 2,2 dm³, com três plantas de trigo. Aos 45 dias após emergência (DAE), as plantas foram inoculadas com uma suspensão de 10(5) mL-1 conídios de Bipolaris sorokiniana. Foram determinados o grau de severidade final da mancha-marrom, a produção de matéria seca da parte aérea e das raízes, e os teores foliares de N e Mn nas plantas de trigo, assim como a disponibilidade de Mn no solo. Verificou-se efeito das fontes de N e das doses de Mn apenas na severidade da mancha-marrom e nos teores de Mn no solo e nas folhas. Houve respostas quadráticas para os teores de Mn no solo e nas folhas e para a severidade da mancha-marrom no trigo. A fonte amoniacal [(NH4)2SO4] proporcionou maior disponibilidade do Mn no solo do que a fonte nítrica [Ca(NO3)2], que foi acompanhada de aumento do teor foliar de Mn na planta e de diminuição da severidade da mancha-marron em trigo.

The nitrogen source applied to crops may alter some soil properties such as pH, resulting in changes in the soil nutrient availability and plant nutrient uptake. Manganese (Mn), which can influence the plant susceptibility to diseases, may even affect host-pathogen relationships. The objective of this study was to evaluate the effect of soil application of two N sources and five Mn doses on the severity of the wheat spot blotch disease. Additionally, shoot and root dry matter production, plant Mn uptake and soil Mn availability were evaluated. An experiment in a randomized block design was carried out in a greenhouse, in a 2 × 5 factorial scheme with two N sources [(NH4)2SO4 and Ca(NO3)2] and five Mn doses (0; 2.5; 5.0; 10.0 and 20.0 mg dm-3) with four replications. Plants were grown in a dystrophic Red Latosol (Oxisol), in 2.2 dm³ plastic pots, with three wheat plants per pot. Forty-five days after emergence (DAE) the plants were inoculated with a Bipolaris sorokiniana suspension containing 10(5) conidial fungi per mL. The disease severity degree, shoot and root dry matter production, and the N and Mn leaf contents in the wheat plants were determined, as well as the soil Mn availability. The N sources and Mn doses affected only the disease severity degree, soil available Mn and leaf Mn. Quadratic responses were found for the contents of soil Mn, leaf Mn and disease severity degree as a function of the increased Mn (MnCl2.4H2O) rates applied to soil. The ammonium-based source [(NH4)2SO4] resulted in a greater Mn availability than the nitric-based source [Ca(NO3)2], which was followed by an increase in foliar Mn and a drop in the severity degree of wheat spot blotch.

A toxidez de Mn pode ser um problema comum nas regiões tropicais com predominância de solos ácidos. Entretanto, variações das concentrações desse nutriente nas plantas têm sido atribuídas também a diferenças inter e intra-específicas. O presente estudo foi desenvolvido em casa de vegetação e teve como objetivo avaliar as causas de tolerância diferencial à toxidez de Mn. Os cultivares de soja [Glycine max (L.) Merrill] Santa Rosa, IAC-15 e IAC-Foscarin 31 foram cultivados em solução nutritiva (pH 5,0) com cinco doses de Mn (2, 100, 150, 200 e 250 µmol L-1). O delineamento experimental foi o de blocos completos ao acaso em esquema fatorial 5 x 3 (cinco doses de Mn e três cultivares), com três repetições. Os cultivares IAC-15 e Santa Rosa exibiram sintomas visuais de toxidez. As concentrações nas folhas associadas ao excesso foram de 1.000 mg kg-1. Entretanto, o IAC-15 apresentou maior produção de grãos e de matéria seca da parte aérea, acompanhado pelo IAC-Foscarin 31 (intermediário) e Santa Rosa (menor produção). O maior comprimento total de raízes, as maiores produções de matéria seca de raízes e o acúmulo de Mn neste tecido, bem como a maior compartimentalização deste nutriente no apoplasto, conferiram ao IAC-Foscarin 31 maior tolerância ao excesso de Mn na solução. Há, pois, indicações de diferenças genotípicas entre os cultivares e de que vários mecanismos atuam conjuntamente na tolerância ao excesso de Mn em solução.

Manganese (Mn) toxicity may be a constraint for crop production in acid soils of tropical regions. However, variations of Mn concentrations in plant tissues are also related to the genotypic differences. A greenhouse experiment was carried out to evaluate Mn tolerance of three soybean cultivars [Glycine max (L.) Merrill]. Cultivars Santa Rosa, IAC-15 and IAC-Foscarin 31 were evaluated under five Mn rates (2, 100, 150, 200, and 250 µmol L-1) in nutrient solution (pH 5.0). The experiment in randomized blocks was a 5 x 3 factorial of five Mn doses and three cultivars, with three replications. IAC-15 and Santa Rosa leaves showed visual symptoms of Mn toxicity. At toxic Mn levels in solution, the average Mn concentration in the leaf blades was close to 1,000 mg kg-1. Nevertheless, grain and dry matter in the aerial parts was higher for IAC-15 than IAC-Foscarin 31 (intermediate yield) and Santa Rosa (lowest yield). The greatest total root length and root dry matter yield, as well as root Mn accumulation and compartmentalization in root apoplast of IAC-Foscarin 31 contributes to explain differences in tolerance to the excess. There are, therefore, indications of genotypic differences among the soybean cultivars and that several mechanisms are involved in the tolerance to high Mn levels.

A carência de informações na literatura sobre a amostragem de folhas da gravioleira, particularmente, a definição da posição da folha na copa das árvores e das folhas nos ramos ainda é um fator limitante para a diagnose foliar dessa cultura. Objetivando determinar a parte da planta indicada para a amostragem de folhas e a avaliação do estado nutricional da gravioleira conduziu-se um experimento no Campo Experimental da Embrapa Agroindústria Tropical, em Pacajus (CE), no período de março a abril de 2003. Colheram-se folhas de três posições da copa (terço superior, terço médio e terço inferior) e três posições no ramo (folhas da parte apical, mediana e basal) e determinaram-se os teores de P, K, Ca, Mg, S, Fe, Cu, Zn e Mn. Os resultados permitem sugerir que os teores de minerais das folhas da parte mediana da copa das árvores e na posição mediana do ramo refletem melhor o estado nutricional da frutífera.

The lack of information in literature about leaf sampling soursop plant in particular, the definition of the leaf position at the tree top and leaves on the branches is still a limiting factor for the diagnosis of this cultivation. Aiming to determine which is the suitable part of the plant for leaf sampling and evaluate the nutritional status of the soursop plants, an experiment was developed on the experimental farm Embrapa - CNPAT, at Pacajus-CE, in the period from March to April, 2003. One collected leaves from three positions at the top (upper third, medium third and lower third) and three positions on the branches (apical part leaves, basal and medium) and one determined the tenor of P, K, Ca, Mg, S, Fe, Cu, Zn and Mn. The results allow to suggest that the mineral levels of the medium part of leaves at the top of the trees on the medium position of the branch, reflect best nutritional status of the plant.