ABSTRACT The use of resistant cultivars is the main strategy to control Fusarium wilt on tomato, caused by Fusarium oxysporum f. sp. lycopersici . This study aimed to quantify the incidence and distribution of this disease in the region of Nova Friburgo, RJ, as well as the type of resistance of tomato cultivars to the three FOL races. Samples of healthy and wilted plants from 40 properties were evaluated for the presence of vascular discouloration. Seventeen tomato cultivars were evaluated for resistance to the three FOL races using a grading scale. Classification for resistance/susceptibility, incidence and percentage of infection of the vascular system, fresh weight accumulation and seedling length were determined. All the cultivars analysed behaved as similar to immune (SI) to race 1 of FOL and similar to immune or partial resistance to race 2. Only Aguamiel cultivar presented a SI reaction to FOL race 3. None of the cultivars presented a SI reaction to the three races. It can be concluded that failures on the control of the disease in this region can be attributed to the majority use of cultivars with incomplete resistance to the three FOL races. The seed packages also contain incomplete information about FOL resistance.

ABSTRACT. Brassica spp. production can be negatively affected by clubroot, which is caused by the protozoan Plasmodiophora brassicae Woronin. Most of the information on clubroot control is derived from studies in temperate regions. Here, management strategies were evaluated to reduce broccoli (Brassica oleracea L. var. italica Plenck) crop losses owing to clubroot in tropical mountain regions. The first experiment revealed the effect of green manure from coriander (Coriandrum sativum L.), sunn hemp (Crotalaria juncea L.), sweet corn (Zea mays L.), and spontaneous vegetation (control) associated with broccoli seedlings of 4 different sizes. In the second experiment, the effect of soil amendments (limestone and steel slag) in conjunction with poultry litter (fresh or composted for 45 days) and without poultry litter (control), was assessed. Both field experiments sought to evaluate the disease intensity, plant development (root growth, biomass, and nutrient accumulation), and yield. Sunn hemp and coriander biomass resulted in higher healthy root volumes and dry weights of broccoli. However, such benefits were not derived from corn treatment. Compared to smaller seedlings (10 mL cell and 20 days of age, and 16 mL cell and 24 days of age), the use of larger seedlings (35 mL cell and 28 days of age, and 50 mL cell and 32 days of age) resulted in lower intensity of clubroot and increased the average yield by 143% in summer crops. Steel slag, like limestone, corrected soil acidity and resulted in plant growth; however, clubroot intensity was not significantly affected. Fresh and composted poultry litter increased the percentage of diseased roots compared with the control; however, broccoli yield was not affected by the treatments. Using green manure (sunn hemp or coriander) and well-developed seedlings is recommended as a strategy to reduce losses induced by clubroot during broccoli cultivation.

ABSTRACT: This study evaluated the levels of heavy metals in the soil and castor bean plant after fertilization with sewage sludge (SS) subjected to different stabilization processes. The study was conducted in a Haplic Cambisol with the following treatments: control (CO), fertilization with solarized sewage sludge (SSS), composted sewage sludge (CSS), vermi composted sewage sludge (VSS), limed sewage sludge (LSS), and mineral fertilizer (MF). The experimental design included a subdivided plot scheme with fertilization being the primary factor and soil layers or leaf parts being the secondary factor. The data obtained were analyzed using analysis of variance and the Scott-Knott test with 5% significance. Fertilization with SSS, CSS, and LSS led to the highest increase in Zn in the soil, mainly in the surface layer. In the leaf tissues, Zn and Cu levels were higher with the CO and SSS treatments, whereas the Ni level was higher with SSS, CSS, VSS, and MF treatments. In general, Zn and Cu levels were higher in the leaf limb than in the petiole, whereas Ni, Pb, and Cr levels were higher in the petiole than in the leaf limb. In any case, no symptoms of toxicity in the plants and no risk of soil contamination were observed with any of the fertilization treatments.

RESUMO: O objetivo deste trabalho foi avaliar os teores de metais pesados no solo e na planta de mamoneira em resposta à adubação com lodo de esgoto (LE) submetido a diferentes processos de estabilização. O experimento foi desenvolvido em Cambissolo Háplico com os tratamentos: testemunha, adubação com LE solarizado, LE compostado, LE vermicompostado, LE caleado e adubação mineral. O delineamento experimental foi em esquema de parcelas subdivididas, sendo as adubações o fator primário e as camadas do solo ou as partes da folha o fator secundário. Os dados obtidos foram submetidos à análise de variância e teste de Scott-Knott a 5% de probabilidade. No solo, as adubações com LE solarizado, compostado e caleado promoveram os maiores incrementos dos teores de Zn, principalmente na camada superficial. No tecido foliar, os teores de Zn e Cu foram mais elevados na testemunha e no LE solarizado, enquanto o Ni foi mais elevado nos LE solarizado, compostado, vermicompostado e na adubação mineral. De modo geral, os maiores teores de Zn e Cu ocorreram no limbo foliar em comparação ao pecíolo, enquanto os teores de Ni, Pb e Cr foram mais elevados no pecíolo do que no limbo foliar. Contudo, não foram constatados sintomas de toxidez nas plantas e nenhum risco de contaminação do solo com os diferentes tipos de adubações realizadas.

RESUMEN Introducción. A partir de investigaciones iniciadas durante el año 1986, que constituyen la línea base de la información, se demuestra por primera vez, la capacidad de resiliencia de los suelos Ferralíticos Rojos en la llanura kárstica meridional Habana-Matanzas, como resultado de un proceso multifactorial, condicionado no solo por las propiedades intrínsecas de la cobertura edáfica y condiciones de uso, sino dependiente de las condiciones geólogo-geomorfológicas. Métodos. Se tomó como referencia el perfil C1 (sin erosión aparente), localizado en un área en biostasia como línea base, para evaluar en los diferentes escenarios la magnitud de pérdida de los suelos Ferralíticos Rojos a través de las depresiones kársticas mediante el modelo de predicción de Kay et al. (1994). Resultados. Se concluyó que bajo prácticas agrícolas normales los suelos Ferralíticos Rojos afectados por erosión se recuperarían en un período de 50 años, mientras que de acuerdo con el grado de impurezas de las calizas les tomaría entre 100 años y 600 años. Se recomendó a las autoridades la necesidad de aplicar definitivamente los resultados obtenidos por más de 3 décadas en la determinación de las modalidades específicas que asume la degradación de los suelos Ferralíticos Rojos, para que su degradación deje de ser mito y se convierta en un asunto de prioridad para el plan de soberanía alimentaria y educación nutricional de Cuba post-COVID-19, ya que representan el máximo potencial para satisfacer lo que el país actualmente demanda para las producciones agropecuarias.

ABSTRACT Introduction. Based on research initiated during 1986, which constitutes the baseline information, the resilience capacity of the Red Ferrallitic soils in the southern Karstic plain Havana-Matanzas is demonstrated for the first time, as a result of a multifactorial process, conditioned not only by the intrinsic properties of the soil cover and conditions of use, but also dependent on the geological-geomorphological conditions. Methods. The C1 profile (without apparent erosion), located in an area in biostasis, was used as a baseline to evaluate the magnitude of loss of Red Ferrallitic soils through Karst depressions in different scenarios using the prediction model of Kay et al. (1994). Results. It was concluded that under normal agricultural practices the Red Ferrallitic soils affected by erosion would recover in a period of 50 years, while according to the degree of limestone impurities it would take between 100 to 600 years. It was recommended to the authorities that it was necessary to definitively apply the results obtained for more than three decades in the determination of the specific modalities assumed by the degradation of the Red Ferrallitic soils, so that their degradation ceases to be a myth and becomes a priority issue for the food sovereignty and nutritional education plan of Cuba post-COVID-19, since they represent the maximum potential to satisfy what the country currently demands for agricultural productions.

Abstract To evaluate the phytostabilization of a Zn and Cd contaminated industrial residue, it was conducted an experiment with Brachiaria humidicola in a greenhouse, using an alkaline residue (calcium silicate) and an organic residue (sludge from a brewery factory) to reduce the heavy metal solubility in the Ingá residue. The addition of alkaline and organic industrial residues caused a significant reduction in the percentages of Zn and Cd in the soluble and exchangeable fractions, and predominance of the same ones in the most stable chemical fractions, such as complexed and precipitated compounds. The B. humidicola presented tolerance and potential of revegetation of the Ingá residue. greenhouse calcium silicate sludge factory fractions compounds B

Resumo Com o objetivo de avaliar a fitoestabilização de um resíduo industrial contaminado com Zn e Cd, foi utilizada a Brachiaria humidicola em um experimento conduzido em casa-de-vegetação, utilizando um resíduo alcalino (silicato de cálcio) e um resíduo orgânico (lodo do biodigestor de uma cervejaria) para reduzir a solubilidade de metais pesados no resíduo Ingá. A adição de resíduos industriais, alcalino e orgânico, provocou uma significativa redução nas percentagens de Zn e Cd nas frações solúvel e trocável, e predominância dos mesmos em frações químicas mais estáveis, como complexados e precipitados. A B. humidicola apresentou tolerância e potencial de revegetação do resíduo Ingá. casadevegetação, casadevegetação casa vegetação, vegetação casa-de-vegetação silicato cálcio lodo cervejaria Ingá industriais trocável estáveis precipitados B

Sequential extraction is not totally effective to dissolve distinct forms of trace elements. The extractive solution, for example, can dissolve less of the target fraction and more than another not wished fraction. The goal of this work is to compare the extraction of native iron with three sequential extraction methods of the heavy metals, using three soils with different physical chemistry characteristics: a histosol, an oxisol, and a mollisol. The results obtained in this work demonstrate that a smaller relation soil/extractor results in a larger extraction in almost all phases. The use of many stages of the sequential extraction, with the purpose of more association of the metal with different components of the soil, can result, among other things, in modification of the substratum by the action of the reagents used, besides reducing the selectivity of the more specific extractors. Readsorption and redistribution of the heavy metals could have happened with larger intensity in the fraction where hidroxilamine was used with higher temperature. Sequential extraction of iron, without enrichment of soil samples, in the respective fractions in each method, it was important to better understand the behavior of the reagents considered specific to each form of the metal in soil.

Samples of soils treated with sugarcane’s industrial residues (vinasse and filter cake) and their respective control areas at Campos dos Goytacazes-RJ, were analysed for total contents of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn in 1995. The results showed that the use of vinasse for more than 15 years in volumes of 300 m3 ha- 1 .year-1, did not increase the concentrations of the heavy metals in the Entisol and Inceptisol soils. The Inceptisol that received filter cake had the concentrations of all heavy metals increased significantly, with the exception of Zn and Mn. Even though the heavy metals concentrations were higher in this treatment the sequential extraction showed that these elements were present in an unlabile form in the soil. sugarcanes sugarcane s GoytacazesRJ, GoytacazesRJ Goytacazes RJ, RJ Goytacazes-RJ Cd Co Cr Cu Mn Ni 1995 30 m ha .year1, year1 year .year 1, .year-1 significantly soil 199 3 .year1 .year- 19

RESUMO A mostras de um solo gley pouco húmico, antiga lagoa de vinhaça, e dois cambissolos, um fertirrigado com vinhaça e outro com aplicação de torta de filtro, cultivados com cana-de-açúcar, em Campos dos Goytacazes (RJ) , foram analisadas para teores totais de Cd, Co, Cr, Cu, Mn, Ni, Pb e Zn e comparadas com áreas controle em 1995. Os resultados mostraram que a vinhaça só trouxe aumento significativo para os teores totais de Zn. O Cambissolo com torta de filtro apresentou aumentos significativos para Cd, Co, Cr, Cu, Ni e Pb, sendo que na extração seqüencial, os resultados mostraram que a maior percentagem desses elementos encontrava-se na fração residual, de baixa biodisponibilidade. húmico cambissolos canadeaçúcar, canadeaçúcar cana açúcar, açúcar cana-de-açúcar RJ (RJ Cd Co Cr Cu Mn 1995 seqüencial encontravase encontrava se residual biodisponibilidade 199 19 1

Com o objetivo de avaliar a contaminação do solo, sedimentos, água e plantas por metais pesados, decorrente do uso de agroquímicos, na microbacia de Caetés em Paty do Alferes, RJ, amostras de solo foram analisadas, em 1996, para obter os teores totais de Cd, Co, Cu, Mn, Ni, Pb e Zn de duas áreas com diferentes declividades (25% e 45%) tendo, ambas, como cobertura vegetal, capoeira, pasto e olericultura. Os resultados referentes aos solos sob pastagem (antiga área de olericultura) mostraram maiores teores de metais pesados do que a área de capoeira. Entretanto, esses valores não atingiram níveis críticos no solo, e esses elementos estavam presentes em formas químicas pouco disponíveis para absorção pelas plantas, como foi constatado na análise de metais pesados em tomate (Lycopersicum esculentum L.), pimentão (Capsicum annuum L.), repolho (Brassica oleracea L.) e pepino (Cucumis sativus L.), que apresentaram níveis baixíssimos desses elementos. Nas amostras de sedimentos, o comportamento dos metais pesados foi semelhante ao obtido nos solos, estando esses elementos distribuídos em maior porcentagem nas frações residual, ligadas a óxidos de Mn e Fe e ligadas à matéria orgânica. As amostras de água do córrego e do açude que cortam a microbacia apresentaram valores acima dos padrões internacionais com relação a Cd, Pb e Mn.

To evaluate heavy metals contamination of soil, sediments, water and plants of the Caetés watershed, in Paty do Alferes, RJ, Brazil, by the use of agrochemicals, samples from two areas with different declivities (25% and 45%) were analysed, in 1996, for total contents of Cd, Co, Cu, Mn, Ni, Pb and Zn. The results for the soils under pasture (lately horticulture) showed higher heavy metals contents in comparison to the brushwood area. However, these contents didn't reach the critical levels for soils, and these elements were present in chemical forms of low disponibility for plant absorption, as it was seen in the very low levels of heavy metals in the samples of tomato (Lycopersicum esculentum L.), green pepper (Capsicum annuum L.), cabbage (Brassica oleracea L.) and cucumber (Cucumis sativus L.). The behaviour of the heavy metals in the sediment samples were the same of the soil samples, being these elements distributed, in higher percentages, in the residual, bonded to Mn and Fe oxides and bonded to organic matter fractions. The water samples from the stream and dam showed higher levels than the international standards for Cd, Pb and Mn.