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Abstract Background Disease suppressiveness of soils to fungal root pathogens is typically induced in the field by repeated infections of the host plant and concomitant changes in the taxonomic composition and functional traits of the rhizosphere microbiome. Here, we studied this remarkable phenomenon for Bipolaris sorokiniana in two wheat cultivars differing in resistance to this fungal root pathogen. Results The results showed that repeated exposure of the susceptible wheat cultivar to the pathogen led to a significant reduction in disease severity after five successive growth cycles. Surprisingly, the resistant wheat cultivar, initially included as a control, showed the opposite pattern with an increase in disease severity after repeated pathogen exposure. Amplicon analyses revealed that the bacterial families Chitinophagaceae, Anaerolineaceae and Nitrosomonadaceae were associated with disease suppressiveness in the susceptible wheat cultivar; disease suppressiveness in the resistant wheat cultivar was also associated with Chitinophagaceae and a higher abundance of Comamonadaceae. Metagenome analysis led to the selection of 604 Biosynthetic Gene Clusters (BGCs), out of a total of 2,571 identified by AntiSMASH analysis, that were overrepresented when the soil entered the disease suppressive state. These BGCs are involved in the biosynthesis of terpenes, non-ribosomal peptides, polyketides, aryl polyenes and post-translationally modified peptides. Conclusion Combining taxonomic and functional profiling we identified key changes in the rhizosphere microbiome during disease suppression. This illustrates how the host plant relies on the rhizosphere microbiome as the first line of defense to fight soil-borne pathogens. Microbial taxa and functions identified here can be used in novel strategies to control soil-borne fungal pathogens.

Analyzing the impacts of climate change on phytosanitary problems in Brazil is crucial due to the country’s special role in global food security as one of the largest producers of essential commodities. This review focuses on the effects of climate change on plant diseases and discusses its main challenges in light of Brazil’s diverse agricultural landscape. To assess the risk of diseases caused by fungi, bacteria, viruses, oomycetes, nematodes, and spiroplasms, we surveyed 304 pathosystems across 32 crops of economic importance from 2005 to 2022. Results show that diseases caused by fungi account for 79% of the pathosystems evaluated. Predicting the occurrence of diseases in a changing climate is a complex challenge, and the continuity of this work is strategic for Brazil’s agricultural defense. The future risk scenarios analyzed here aim to help guide disease mitigation for cropping systems. Despite substantial progress and ongoing efforts, further research will be needed to effectively prevent economic and environmental damage.

Beneficial microbes play crucial role in modern agriculture, serving as biopesticides, biostimulants/biofertilizers, and alleviating abiotic stress in crops. Their multifaceted functions contribute significantly to crop health and sustainability, aligning with the principles of regenerative agriculture by minimizing carbon footprints and reducing dependence on agrichemical inputs. The concept of ‘microbial consortia’, involving the combination of multiple fungal and bacterial species or strains, has gained recognition for its potential advantages over single species/strains applications. This method aims to employ a spectrum of ecological functions, encouraging biological equilibrium within agricultural systems. Recent research highlights how microbial consortia can directly and indirectly enhance plant health, through various mechanisms and interactions with their host plants. This review presents examples demonstrating the efficacy of microbial consortia as biopesticides and biostimulants/biofertilizers. These consortia exhibit potential in managing plant diseases and pests, while also promoting plant growth and mitigating specific abiotic and biotic stresses in crops. This review examines real-world examples considering instances of success and failure, discusses methodologies employed for evaluating interactions, and also addresses challenges in the selection, production, and application of optimal microbial consortia for agricultural use providing valuable insights in the current and future prospects of microbial consortia in modern agriculture.

ABSTRACT Understanding the genetic diversity and mechanisms underlying genetic variation in pathogen populations is crucial to the development of effective control strategies. We investigated the genetic diversity and reproductive biology of Colletotrichum graminicola isolates which infect maize by sequencing the genomes of 108 isolates collected from 14 countries using restriction site-associated DNA sequencing (RAD-seq) and whole-genome sequencing (WGS). Clustering analyses based on single-nucleotide polymorphisms revealed three genetic groups delimited by continental origin, compatible with short-dispersal of the pathogen and geographic subdivision. Intra- and intercontinental migration was observed between Europe and South America, likely associated with the movement of contaminated germplasm. Low clonality, evidence of genetic recombination, and high phenotypic diversity were detected. We show evidence that, although it is rare (possibly due to losses of sexual reproduction- and meiosis-associated genes) C. graminicola can undergo sexual recombination. Our results support the hypotheses that intra- and intercontinental pathogen migration and genetic recombination have great impacts on the C. graminicola population structure. IMPORTANCE Plant pathogens cause significant reductions in yield and crop quality and cause enormous economic losses worldwide. Reducing these losses provides an obvious strategy to increase food production without further degrading natural ecosystems; however, this requires knowledge of the biology and evolution of the pathogens in agroecosystems. We employed a population genomics approach to investigate the genetic diversity and reproductive biology of the maize anthracnose pathogen (Colletotrichum graminicola) in 14 countries. We found that the populations are correlated with their geographical origin and that migration between countries is ongoing, possibly caused by the movement of infected plant material. This result has direct implications for disease management because migration can cause the movement of more virulent and/or fungicide-resistant genotypes. We conclude that genetic recombination is frequent (in contrast to the traditional view of C. graminicola being mainly asexual), which strongly impacts control measures and breeding programs aimed at controlling this disease.

Microbial crop protection products based on Trichoderma have the ability to display multifunctional roles in plant protection, such as pathogen parasitism, enhance nutrient availability and stimulate plant growth, and these traits can be used to enhance the overall agronomic performance of a variety of crops. In the current study, we explored the multifunctional potential of two indigenous Brazilian strains of Trichoderma (T. asperelloides CMAA 1584 and T. lentiforme CMAA 1585) for their capability of controlling Sclerotinia sclerotiorum, a key plant pathogen of cotton, and for their ability of growth promotion in cotton plants (Gossypium hirsutum). Both strains were able to solubilize mineral phosphorus (CaHPO4), to release volatile organic compounds that impaired the mycelial growth of S. sclerotiorum, and to promote the growth of cotton plants under greenhouse conditions. In dual culture, Trichoderma strains reduced the growth rate and the number of sclerotia formed by S. sclerotiorum. By treating sclerotia with conidial suspensions of these Trichoderma strains, a strong inhibition of the myceliogenic germination was observed, as a result of the marked mycoparasitic activity exerted on the sclerotia. The parasitism over S. sclerotiorum was more effective with T. asperelloides CMAA 1584, whilst the biostimulant effects on cotton growth were more pronounced with T. lentiforme CMAA 1585, which also showed a higher capacity of phosphate solubilization. Thus, T. asperelloides CMAA 1584 displays higher efficiency in controlling S. sclerotiorum, while T. lentiforme CMAA 1585 is more suitable as a biostimulant due to its ability to promote growth in cotton plants. Overall, these Trichoderma strains may be used in mixture to provide both pathogen control and promotion of plant growth, and this strategy will support growers in minimizing the use of synthetic fertilizers and fungicides against white mold in cotton crops.

Among the prospective biocontrol agents, the saprophytic filamentous fungus Clonostachys rosea is an excellent necrotrophic mycoparasite of numerous plant pathogenic fungi. However, its commercial development has been hampered by mass production difficulties during solid-state fermentation. Conversely, the submerged liquid fermentation shortens the cultivation time while increasing yields of fungal propagules. However, this method has been overlooked for C. rosea. In this work, we investigated the impact of liquid pre-culture inoculum on the spore production by the two-stage fermentation process using rice grains in comparison to the traditional solid-state fermentation. In parallel, we studied the submerged cultivation of C. rosea by manipulating carbon-to-nitrogen (C:N) ratio and nitrogen source, with the further optimization of spore production in a benchtop bioreactor. Additional bioassays included assessing the bioactivity of water-dispersible microgranules (that contained a submerged conidia) against the whitefly (Bemisia tabaci biotype B) and Sclerotinia sclerotiorum (causal agent of the white mold). Our results showed a maximum concentration of 1.1 × 109 conidia/g-dry-matter after 7 days of cultivation by two-stage fermentation process. The liquid fermentation yielded 1.4 × 109 submerged conidia/ml after 7 days using a medium with a 50:1 C:N ratio, and it also induced the production of microsclerotia (MS) up to 1.35 × 104/ml within 6 days with 10:1 C:N ratio; both media were supplemented with dextrose monohydrate and soybean meal. The fermentation batches carried out in a benchtop bioreactor with medium 50:1 C:N ratio and amended with soybean meal rendered a production peak on the fourth day, corresponding to 1.11 × 109 conidia/ml and 4.35 × 108 colony forming units (CFU)/ml. Following air-drying, the conidia production from air-dried microgranules of C. rosea biomass was estimated at 3.4 × 1010 conidia/g of formulated product upon re-hydration for 7 days. Both submerged conidia and MS of C. rosea inhibited 100% germination of S. sclerotiorum sclerotia by direct parasitism. The air-dried submerged conidia exhibited a suppressive activity on sclerotia (88% mycoparasitism) and early whitefly nymphs (76.2% mortality) that rendered LC50 values of 3.2 × 104 CFU/g soil and 1.5 × 107 CFU/ml, respectively. Therefore, the submerged liquid culture of C. rosea may offer a feasible and cost-effective method for its large-scale production, alleviating critical constraints to their commercial use while providing an additional tool for management of B. tabaci and S. sclerotiorum.

Abstract: The objective of this work was to evaluate the commercial formulations of Bacillus subtilis QST-713 and Bacillus pumilus QST-2808 on mycelial growth inhibition of Thielaviopsis paradoxa, for the control of the pineapple disease and growth promotion in sugarcane. The inhibition of mycelial growth was evaluated in paired culture tests. Bacillus isolates were transferred to Petri dishes 48 hours before the pathogen, and the zone of inhibition was determined. The direct effect of the autoclaved commercial formulations at 0, 0.001, 0.01, 0.1, 1.0, and 10.0% on the inhibition of pathogen mycelial growth was evaluated. Bacillus spp. potential in controlling the disease and promoting plant growth was evaluated in assays on plant development and disease severity, both under controlled conditions and in the field. Bacillus isolates inhibited pathogen mycelial growth; however, the isolates did not control the disease effectively in the growth chamber and in the field. In the field assay without infestation by the pathogen, all treatments with biocontrol agents and fungicide increased the yield of cane stalks and sugar per hectare, compared with the control. In the assay with infestation by the pathogen, the B. pumilus-based product (2.0 L ha-1) and fungicide differed from the control only for the variable number of tillers.

ABSTRACT: The incorporation of organic matter to the soil not only improves nutrient content, but also reduces the survival of Stenocarpella, the causal agent of stalk rot, Diplodia ear rot, and grey leaf spot, in maize stubble. We evaluated the effect of organic waste incorporation on Stenocarpella survival in maize stalks, the activity of suppressiveness-related enzymes, and nutrient contents. We conducted the assays in the municipalities of Lavras and Sete Lagoas, Minas Gerais State, Brazil. Maize stalks infested with Stenocarpella were kept in field conditions for three months after poultry litter, swine manure, fish hydrolysate, compost sewage sludge, and urea application. Infested stalks, without residue amendment, were kept on surface or incorporated into the soil, representing negative and positive controls. Stenocarpella concentration in stalks was assessed using qPCR expressed as cycle threshold number. Sewage sludge, buried stalks, and stalks retained on the surface showed reduction of pathogen inoculum. Swine manure and urea did not reduce the quantity of DNA. In the experiment conducted in Lavras, poultry litter stimulated β-glucosidase, urease and hydrolysis of fluorescein diacetate activities when compared to the negative control. Sewage sludge, poultry litter, and swine manure increased Ca in the soil by 44 %, 38 % and 36 %, respectively, in the experiment conducted in Lavras. Poultry litter increased Ntotal three months after application. The results indicate that organic wastes are promising in improving nutrient content, activity of hydrolysis-related enzymes, but Stenocarpella inoculum dynamics should be taken into consideration when deciding on the specific organic amendment.

Trichoderma species are well known biocontrol agents that are able to induce responses in the host plants against an array of abiotic and biotic stresses. Here, we investigate, when applied to tomato seeds, the potential of Trichoderma strains belonging to three different species, T. parareesei T6, T. asperellum T25, and T. harzianum T34, to control the fully pathogenic strain Pseudomonas syringae pv. tomato (Pst) DC3000, able to produce the coronatine (COR) toxin, and the COR-deficient strain Pst DC3118 in tomato plants, and the molecular mechanisms by which the plant can modulate its systemic defense. Four-week old tomato plants, seed-inoculated, or not, with a Trichoderma strain, were infected, or not, with a Pst strain, and the changes in the expression of nine marker genes representative of salicylic acid (SA) (ICS1 and PAL5) and jasmonic acid (JA) (TomLoxC) biosynthesis, SA- (PR1b1), JA- (PINII and MYC2) and JA/Ethylene (ET)-dependent (ERF-A2) defense pathways, as well as the abscisic acid (ABA)-responsive gene AREB2 and the respiratory burst oxidase gene LERBOH1, were analyzed at 72 hours post-inoculation (hpi) with the bacteria. The significant increase obtained for bacterial population sizes in the leaves, disease index, and the upregulation of tomato genes related to SA, JA, ET and ABA in plants inoculated with Pst DC3000 compared with those obtained with Pst DC3118, confirmed the COR role as a virulence factor, and showed that both Pst and COR synergistically activate the JA- and SA-signaling defense responses, at least at 72 hpi. The three Trichoderma strains tested reduced the DC3118 levels to different extents and were able to control disease symptoms at the same rate. However, a minor protection (9.4%) against DC3000 was only achieved with T. asperellum T25. The gene deregulation detected in Trichoderma-treated plus Pst-inoculated tomato plants illustrates the complex system of a phytohormone-mediated signaling network that is affected by the pathogen and Trichoderma applications but also by their interaction. The expression changes for all nine genes analyzed, excepting LERBOH1, as well as the bacterial populations in the leaves were significantly affected by the interaction. Our results show that Trichoderma spp. are not adequate to control the disease caused by fully pathogenic Pst strains in tomato plants.

O mercado consumidor está exigindo alimentos sem a presença de resíduos de agrotóxicos. Assim, o trabalho teve como objetivo avaliar o controle do bolor verde, em laranjas-Pera, com agentes de biocontrole (Bacillus subtilis e Bacillus licheniformis, Bacillus subtilis (QST 713)), associados ou não ao tratamento térmico. Para tanto, os frutos foram adquiridos em "packinghouse" antes do processamento, sendo lavados e desinfestados com hipoclorito de sódio. Os frutos submetidos a esses tratamentos foram armazenados, por 11 a 28 dias, em temperatura de 10 ºC e UR 90%±5 ou por oito dias a 20 ºC e UR 90%±5. De modo geral, o tratamento térmico reduziu a severidade da doença determinada pela área abaixo da curva do progresso da doença nos frutos e a incidência natural de doenças em pós-colheita de laranja-Pera. Por outro lado, os agentes de biocontrole não controlaram a doença, mostrando que os organismos testados não apresentaram atividade curativa contra o bolor verde.The consumer market demands food without pesticide residues. Therefore, this study focused on evaluating the control of green mold in Pera orange trees with biocontrol agents (Bacillus subtilis, Bacillus licheniformis and Bacillus subtilis (QST 713)), associated or not with heat treatment. The fruit was obtained in packinghouse before processing, being washed and disinfected with the use of Sodium Hypochlorite. Fruits submitted to these treatments were stored from 11 to 28 days at temperature of 10 ºC and RH 90%±5 or for eight days at 20 ºC and 90%±5. In general, the heat treatment reduced the disease severity determine by the area under the disease progress curve in the fruit and the incidence of natural postharvest disease in Pera oranges. On the other hand, biocontrol agents did not control the disease, showing that the organisms tested did not present curative activity against the green mold.

Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in T. harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by i) enhanced growth, ii) increased carbon and nitrogen levels and iii) a higher sensitivity to Botrytis cinerea infections in plants treated with amdS transformants as detected in greenhouse assays. These observations suggest that the increased plant development promoted by the amdS transformants was at expense of defenses.

The objective of this study was to evaluate the sorption and leaching of thiamethoxam in dystrophic Red-Yellow Latosol (LVAd), dystroferric Red Latosol (LVdf) and Red-Yellow Argisol (PVAd) with coffee under the effect of sewage sludge doses. There was thiamethoxam sorption decreasing at higher doses of sewage sludge in LVAd and LVdf. In the PVAd, sorption was higher in samples that received the highest dose of sewage sludge. At 150 days after the application of thiamethoxam, the compound began to be detected in the effluent, in all soils. Dissolved organic carbon had no influence on the thiamethoxam leaching.

The ability of isolates of Bacillus subtilis and Trichoderma spp. to control citrus black spot (CBS) was investigated in ´Natal´ sweet orange orchards. The first experiment was conducted during the 2001/2002 season and four isolates of B. subtilis (ACB-AP3, ACB-69, ACB-72 and ACB-77), applied every 28 days, alone or in combination were tested and compared with fungicide treatments. Two other experiments were carried out during the 2002/2003 season, where the same isolates of Bacillus and two isolates of Trichoderma (ACB-14 and ACB-40) were tested being applied every 28 days in the second experiment, and every 15 days in the third experiment. In the first experiment, the treatment with ACB-69 differed statistically from the control, but did not differ from other biological control agents or mixture of Bacillus isolates. In the second experiment, the treatments with ACB-69 and ACB-AP3 resulted in smaller disease index compared with the control treatment. However, this result was not repeated in the third experiment, where the isolates were applied every 15 days. Disease severity was high in both evaluated seasons and the fungicide treatment was the most effective for disease control.

O objetivo deste trabalho foi avaliar a capacidade de microrganismos de manguezais para controlar a podridão radicular causada por Pythium aphanidermatum e para promover o crescimento em pepino hidropônico (Cucumis sativus). Avaliaram-se 19 microrganismos quanto ao controle da doença em mini-hidroponia. Os microrganismos mais promissores para esse fim - Gordonia rubripertincta SO-3B-2 e a mistura dos isolados G. rubripertincta SO-3B-2, MB-P3A-49, MB-P3-C68 e SO-3L-3, de Pseudomonas stutzeri, e Bacillus cereus AVIC-3-6 - foram, posteriormente, testados quanto à promoção de crescimento do pepineiro, em casa de vegetação. Microrganismos de manguezais podem ter importância funcional no controle biológico da podridão radicular causada por P. aphanidermatum e na promoção do crescimento do pepineiro cultivado em hidroponia. Os microrganismos G. rubripertincta SO-3B-2 e P. stutzeri MB-P3A-49 são promissores na promoção do crescimento das plantas não infestadas com o patógeno.

Due to human activity, large amounts of organic residue are generated daily. Therefore, an adequate use in agricultural activities requires the characterization of the main properties. The chemical and physical characterization is important when planning the use and management of organic residue. In this study, chemical and physical properties of charcoal, coffee husk, pine-bark, cattle manure, chicken manure, coconut fiber, sewage sludge, peat, and vermiculite were determined. The following properties were analyzed: N-NH4+, N-N0(3)-, and total concentrations of N, P, S, K, Ca, Mg, Mn, Zn, Cu, and B, as well as pH, Electrical Conductivity (EC) and bulk density. Coffee husk, sewage sludge, chicken manure and cattle manure were generally richer in nutrients. The EC values of these residues were also the highest (0.08 - 40.6 dS m-1). Peat and sewage sludge had the highest bulky density. Sodium contents varied from 0 to 4.75 g kg-1, with the highest levels in chicken manure, cattle manure and sewage sludge. Great care must be taken when establishing proportions of organic residues in the production of substrates with coffee husk, cattle or chicken manure or sewage sludge in the calculation of the applied fertilizer quantity in crop fertilization programs.Uma diversidade de resíduos orgânicos, oriundos das atividades humanas, é gerada diariamente e demanda pesquisas para avaliar a viabilidade técnica, econômica e ambiental do seu uso agrícola. A caracterização química e física auxiliam no planejamento de uso e no manejo dos resíduos orgânicos, pois permitem avaliar atributos que tornam o uso na agricultura atrativo ou limitante. Este trabalho teve como objetivos a caracterização química e física e a avaliação de teores de nutrientes e de Na em carvão vegetal, casca de café, casca de pínus, esterco bovino, esterco de galinha, fibra de coco, lodo de esgoto, turfa e vermiculita. Os seguintes atributos foram analisados: N-amônio e N-nitrato e os teores totais de N, P, S, K, Ca, Mg, Mn, Zn, Cu, B e Na, além do pH em água, da condutividade eletrolítica (CE) e da densidade aparente dos materiais. A casca de café, o lodo de esgoto e os estercos de galinha e de bovino foram os materiais que apresentaram as maiores concentrações totais de: N, N-amônio, N-nitrato, P, S, K, Ca, Zn, Cu e B; foram, também, os resíduos que apresentaram os maiores valores de CE (0,08 a 40,6 dS m-1). A turfa e o lodo de esgoto mostraram os maiores valores de densidade aparente. Os teores de Na apresentados pelos materiais variaram de 0 a 4,75 g kg-1, sendo os maiores valores verificados para os estercos de galinha e de bovino e o lodo de esgoto. O uso de casca de café, de estercos de bovino e de galinha e do lodo de esgoto demanda maiores cuidados para estabelecer as suas proporções para a produção de substratos ou no cálculo da quantidade a ser utilizada em programas de adubação das culturas.

O objetivo deste trabalho foi comparar uma população de leveduras do filoplano de lírio de um sistema convencional de cultivo com outra de sistema integrado, além de avaliar o antagonismo da levedura Sporidiobolus pararoseus a Botrytis cinerea. A comunidade de leveduras foi estimada pelo método da queda dos balistoporos nos terços inferior, médio e superior das plantas, bem como nas faces adaxial e abaxial das folhas. Nos discos de folhas de plantas do sistema integrado, foi alta a presença da população de leveduras, tendo sido maior na face adaxial das folhas do terço médio das plantas. Para avaliação do antagonismo, foram aplicadas aos discos de folhas as concentrações de 10(5), 10(6) e 10(7) células mL-1 da levedura, em três períodos de inoculação: 24 horas antes; simultânea a; e 24 horas após a inoculação de 10(4) esporos mL-1 de B. cinerea. A incidência, a percentagem de área de discos colonizados e a esporulação de B. cinerea foram avaliadas por meio de diagrama de notas, a partir do quarto dia após a inoculação. Todas as concentrações da levedura reduziram a esporulação de B. cinerea nos discos de folha, em comparação à testemunha, e a concentração de 10(7) esporos mL-1 foi a mais eficiente.The objective of this study was to compare a population of phylloplane yeasts in lilies cultivated in a conventional cultivation system to other lilies in an integrated system, as well as to evaluate the antagonism of Sporidiobolus pararoseus to Botrytis cinerea. The yeast community was estimated by the spore-fall method in the lower, middle and upper thirds of the plants, as well as in the abaxial and adaxial leaf surfaces. The yeast population was high on the leaf discs of the plants from the integrated system, and it was higher on the adaxial surface and on leaves from the middle third of the plants. To evaluate yeast antagonism, concentrations of 10(5), 10(6) and 10(7) cells mL-1 were sprayed on the leaf discs in three inoculation times: 24 hours before; simultaneously; and 24 hours after inoculation with B. cinerea at a concentration of 10(4) spores mL-1. The incidence and percentage of disc tissue area colonized and of B. cinerea sporulation were evaluated through a category scale, starting from the fourth day after the inoculation. All yeast concentrations reduced B. cinerea sporulation on the leaf discs in comparison to the control, and the yeast concentration of 10(7) cells mL-1 was the most effective.

Objetivou-se caracterizar, por meio de espectroscopia no infravermelho com transformada de Fourier (IVTF), possíveis mudanças na natureza química de ácidos húmicos (AHs) extraídos de amostras de Latossolo (0-10 cm) do Campo Experimental da Embrapa Meio Ambiente, em Jaguariúna (SP). Os dados foram obtidos após seis cultivos de milho e a aplicação de doses variáveis de lodo de esgoto de Barueri (LB) (base seca), conforme os tratamentos avaliados: LB0, LB1, LB2, LB4 e LB8, sendo 0, 1, 2, 4 e 8 vezes a necessidade de N para o milho. Como referência, foi amostrada uma área sob mata. Foram obtidos espectros de ácidos húmicos e do lodo de esgoto utilizado no experimento, e calculados os índices de hidrofobicidade (IH) e de condensação (IC) nas amostras de ácidos húmicos. Foram notadas pequenas alterações na natureza química de AHs de áreas tratadas com lodo de esgoto, em relação à testemunha. Os AHs apresentam grupos aromáticos, -OH fenólicos, -COOH, estruturas alifáticas, carboidratos e impurezas minerais. O uso contínuo de elevadas doses de LB reduziu a concentração de C-alifático e o grau de condensação dos ácidos húmicos, o que sinaliza que há frações orgânicas com maior biodisponibilidade no solo. Na área de mata, o material húmico se caracteriza pelo caráter hidrofóbico e pelo baixo grau de condensação.This study was carried out to characterize the possible changes in the chemical nature of humic acids extracted from an Oxisol (0-10 cm) by Fourier transform infrared spectroscopy (FTIR), in the experimental area of Embrapa Meio Ambiente, in Jaguariúna (SP), Brazil. The data were obtained after six corn cultivations, and application of variable doses of sewage sludge (dry basis) from Barueri (BSS), in the treatments: BSS0 - control without sewage sludge application; NPK - mineral fertilization as required by corn; application of BSS to supply one (BSS1), two (BSS2), for four (BSS4), and eight (BSS8) times the N required by corn. As a reference, a forest area close to the experiment was also sampled. FTIR spectra of humic acids (HA) and the sewage sludge used in the experiments were obtained, and the hydrophobicity (HI) and condensation (CI) indexes for the HA samples were calculated. Small changes in the chemical nature of HA from soil treated with BSS were observed in comparison to that from the control soil. The HA analyzed contained aromatic, phenolics, and carboxylic groups, aliphatic structures, carbohydrates and mineral impurities. The continuous use of high BSS doses reduced the aliphatic-C and condensation degree of HA in the soil, which indicates the presence of organic materials with higher bioavailability in these areas. In the area under forest, the HA fraction was characterized by the hydrophobic character and low condensation degree.

Human activities are altering greenhouse gas concentrations in the atmosphere and causing global climate change. In the near future, there will certainly be changes in the Brazilian phytosanitary scenario attributed to global climate change. The impacts of climate change can be positive, negative or neutral, since these changes can decrease, increase or have no impact on diseases, depending on each region or period. These impacts will also be observed on plants and other organisms as well as on other agroecosystem components. However, these impacts are not easily determined, and consequently, specialists from several areas must go beyond their disciplinary boundaries and placing the climate change impacts in a broader context. This review focuses on the discussion of different aspects related to the effects of climate change on plant diseases. On the geographical and temporal distribution of diseases, a historical context is presented and recent studies using data of forecast models of future climate associated with disease simulation models are discussed in order to predict the distribution in future climate scenarios. Predicted future disease scenarios for some crops in Brazil are shown. On the effects of increasing concentrations of atmospheric CO2 and other gases, important aspects are discussed of how diseases change under altered atmospheric gases conditions in the future. The consequences of these changes on the chemical and biological control of plant diseases are also discussed.As atividades antrópicas estão alterando as concentrações de gases de efeito estufa da atmosfera e causando mudanças no clima do planeta. Certamente, num futuro próximo, devido às mudanças climáticas globais, ocorrerão modificações no cenário fitossanitário brasileiro. Os impactos podem ser positivos, negativos ou neutros, pois as mudanças podem diminuir, aumentar ou não ter efeito sobre as doenças, em cada região ou época. Esses impactos também serão observados sobre as plantas e outros organismos, além de outros componentes do agroecossistema. Porém, esses impactos não são facilmente determinados e, desta forma, os especialistas das diferentes áreas precisam ir além de suas disciplinas e abordar os impactos das mudanças climáticas em um contexto mais amplo. Nessa revisão são discutidos os aspectos relacionados com os efeitos das mudanças climáticas sobre as doenças de plantas. Na distribuição geográfica e temporal das doenças, um contexto histórico é apresentado, incluindo estudos recentes utilizando dados de modelos de previsão do clima futuro associados com modelos de simulação da doença a fim de predizer a distribuição nos cenários climáticos futuros. Também são apresentados os cenários futuros de previsão de doenças de algumas culturas no Brasil. Sobre os efeitos do aumento da concentração de CO2 atmosférico e outros gases são discutidos importantes aspectos do comportamento das doenças sujeitas às condições alteradas de gases atmosféricos no futuro. As conseqüências dessas alterações sobre o controle químico e biológico das doenças de plantas também são discutidas.

O objetivo deste trabalho foi avaliar o efeito da aplicação contínua de doses crescentes de lodo de esgoto sobre os teores de carbono (C) associados à fração leve (C-FL) e à fração pesada (associado à areia - C-areia; associado ao silte - C-silte - e associado à argila - C-argila) de matéria orgânica em amostras de Latossolo. O experimento foi instalado em 1999, em Jaguariúna, SP, e os dados foram obtidos após a sexta aplicação de lodo de esgoto com doses acumuladas em base seca - 0, 30, 60, 120 e 240 Mg ha-1 -, após seis cultivos subseqüentes de milho. Os tratamentos foram: testemunha, sem adição de lodo (L0); aplicação de lodo de esgoto para fornecer uma (L1), duas (L2), quatro (L4) e oito (L8) vezes a dose de nitrogênio requerida pelo milho. Como referência, foi amostrada uma área sob mata nativa, adjacente ao local do experimento. O acréscimo nas doses de lodo de esgoto aplicadas aumenta de modo linear os teores de C orgânico, C-silte e C-areia, e não interfere nos teores de C-argila. À medida que se aumenta a dose de lodo de esgoto até 120 Mg ha-1, há acréscimo no teor de C-FL no solo. Em relação ao C orgânico, os teores de C associado aos compartimentos avaliados de matéria orgânica do solo têm a seguinte ordem de contribuição: C-FLThe objective of this work was to evaluate the effect of the continued application of increasing doses of sewage sludge on the contents of carbon (C) associated to the light fraction (LFC) and to the heavy fraction (sand C, siltC and clayC) of soil organic matter, in Oxisol samples. The experiment was installed in 1999, in Jaguariúna, SP, Brazil. The data were obtained after the sixth sewage sludge (SS) application, and six corn cultivation cycles with accumulated doses (dry base) 0, 30, 60, 120 and 240 Mg ha-1, and the treatments were: control, without sewage sludge addition (LO); application of sewage sludge to furnish one (L1), two (L2), four (L4), and eight (L8) times the N required by corn. As a reference, an adjacent area under forest was also sampled. The increase in the applied sewage sludge doses increases linearly the content of organic C (org C), siltC and sandC. As the sewage sludge dose is increased up to 120 Mg ha-1, there is an increase in the content of LFC. The content of C associated to the evaluated compartments of soil organic matter follows this contribution order: FL-C

The objectives of this study were to evaluate the combined effects of soil biotic and abiotic factors on the incidence of Fusarium corn stalk rot, during four annual incorporations of two types of sewage sludge into soil in a 5-years field assay under tropical conditions and to predict the effects of these variables on the disease. For each type of sewage sludge, the following treatments were included: control with mineral fertilization recommended for corn; control without fertilization; sewage sludge based on the nitrogen concentration that provided the same amount of nitrogen as in the mineral fertilizer treatment; and sewage sludge that provided two, four and eight times the nitrogen concentration recommended for corn. Increasing dosages of both types of sewage sludge incorporated into soil resulted in increased corn stalk rot incidence, being negatively correlated with corn yield. A global analysis highlighted the effect of the year of the experiment, followed by the sewage sludge dosages. The type of sewage sludge did not affect the disease incidence. A multiple logistic model using a stepwise procedure was fitted based on the selection of a model that included the three explanatory parameters for disease incidence: electrical conductivity, magnesium and Fusarium population. In the selected model, the probability of higher disease incidence increased with an increase of these three explanatory parameters. When the explanatory parameters were compared, electrical conductivity presented a dominant effect and was the main variable to predict the probability distribution curves of Fusarium corn stalk rot, after sewage sludge application into the soil.

Este estudo teve como objetivo avaliar o efeito da aplicação contínua de doses de lodo de esgoto oriundo da Estação de Tratamento de Esgoto de Barueri, SP, sobre os teores e estoques de C e sobre as alterações na distribuição de substâncias húmicas em Latossolo Vermelho distroférrico. O experimento foi instalado em 1999, no Campo Experimental da Embrapa Meio Ambiente, em Jaguariúna-SP; os dados foram obtidos após a sexta aplicação de lodo e cultivo sucessivo de milho. Foram utilizadas, nas diferentes parcelas experimentais, as seguintes doses acumuladas de lodo de esgoto (base seca): 0, 30, 60, 120 e 240 Mg ha-1, sendo estudados os tratamentos: (L0) testemunha sem adição de lodo; e aplicação de lodo de esgoto visando fornecer uma (L1), duas (L2), quatro (L4) e oito (L8) vezes a dose de N requerida pelo milho. Foram avaliados os teores e o estoque de C orgânico nas camadas de solo de 0-10, 10-20, 20-40 e 40-60 cm. Os teores de C associados às substâncias húmicas foram avaliados na camada de solo de 0-10 cm. O teor e o estoque de C orgânico aumentaram com o acréscimo nas doses de lodo de esgoto aplicadas, até a camada de solo de 0-20 cm. A maior parte (50-66 %) do C associado às substâncias húmicas está presente no solo na forma de humina, seguido por C-fração ácidos fúlvicos e C-fração ácidos húmicos, nesta ordem. A aplicação de lodo de esgoto implica maior acúmulo de substâncias húmicas no solo, mas as proporções de C-humificado da matéria orgânica não são alteradas.This study was carried out to evaluate the effect of continuous sewage sludge applications (Sewage Treatment Station of Barueri, São Paulo State, Brazil) on the C content and stock and on the distribution of C-humic fractions of a Red Latosol (Oxisol). The experiment was installed in 1999 on an experimental field of Embrapa Environment, in Juaguariúna (SP). The data were collected after the sixth sludge application (SS) with corn cultivation. The following accumulated SS doses (dry base) were tested: 0, 30, 60, 120, and 240 Mg ha-1 and the treatments were: control without SS addition(L0); SS application to supply one (L1), two (L2), four (L4) and eight (L8) times the N corn requirement. Carbon contents and stocks were evaluated in the soil layers 0-10, 10-20, 20-40 and 40-60 cm, and the C associated to humic substances 0-10 cm deep. As the SS applications increased, the C content and stock rose in the 0-20 cm soil layer. Most soil C (50-66 %) is associated to the humin pool, followed by fulvic acid fraction-C and then humic acid fraction-C. Sewage sludge applications result in higher contents of C-humic substances in soil, though the proportion of mineralized C in soil humus remained unchanged.

Sludge applications have been used to maintain fertility of agricultural soils without damaging the natural ecosystem. The aim of this study was evaluating the influence of sewage-sludge addition on the quality of organic matter (OM) of a Brazilian Oxisol by Laser Induced Fluorescence (LIF). LIF was used to analyze OM of whole soil and different soil fractions separated by chemical and physical methods. The high fluorescence contribution of humin fraction to the fluorescence of whole soils was shown, stressing the importance of studying OM associated to mineral matrix of soil. Spectra with different shapes were obtained for every particle size fraction, indicating differences in organic compounds bounded to them. The fraction with the higher carbon content was the 2-20 µm, that contains ~5% C and represents only 10% in soil, but stores 34-39 % of total C and shows the highest fluorescence intensity. The spectrum of this fraction shows its heterogeneity and a higher concentration of compounds which fluorescence is centered at 510 nm. This indicates a higher concentration of unsaturated bond systems capable of high degree of resonance, increased conjugation of the electron pi system, and higher aromaticity comparing with other fractions. No differences were detected for treatments of sewage-sludge applications. LIF spectroscopy is a promising technique for OM studies in whole soils, allowing to study spatial distribution of OM within the soil's mineral matrix, including Oxisols.A aplicação do lodo de esgoto é utilizada como alternativa de conservação e manutenção da fertilidade dos solos sem prejudicar o ecossistema. O objetivo do presente trabalho foi avaliar a influência da aplicação de lodo de esgoto sobre a matéria orgânica (MO) de um Latossolo vermelho amarelo brasileiro, através da fluorescência induzida por laser (LIF). A LIF foi utilizada para analisar a fluorescência do solo intacto e suas frações químicas e físicas. Houve grande contribuição da fração humina à fluorescência do solo intacto, remarcando a importância de estudar a matéria orgânica (MO) associada à matriz mineral do solo. Para cada fração granulométrica foram obtidos espectros com diferentes perfis, indicando diferenças nos compostos orgânicos a elas ligados. A fração 2-20 µm, que apresentou maior conteúdo de carbono (~5%), representa somente 10% do solo mas acumula 34-39 % do conteúdo total de carbono do mesmo e mostrou a maior intensidade de fluorescência. O espectro desta fração mostra sua heterogeneidade e alta concentração de compostos cuja fluorescência é centrada nos 510 nm, o que indica alta concentração de sistemas com ligações insaturadas, com alto grau de ressonância e maior conjugação do sistema de eletrons pi, indicando maior aromaticidade quando comparado as outras frações. Não foram observadas diferenças significativas entre os tratamentos de lodo de esgoto. A LIF é uma técnica promissora para caraterizar a MO de solos intatos, permitindo estudar sua distribuição na matriz mineral do solo, inclusive nos Latossolos.

O lodo de esgoto é uma fonte importante de nutrientes para as culturas; contudo, os teores de metais pesados em sua constituição podem limitar seu uso em solos agrícolas. O objetivo deste estudo foi avaliar o efeito de doses de lodos de esgoto oriundos das Estações de Tratamento de Esgoto de Barueri (LB) e de Franca (LF), SP, sobre os teores de metais pesados em folhas e grãos de milho. O experimento foi realizado no Campo Experimental da Embrapa Meio Ambiente, em Jaguariúna (SP), no período de 1999 a 2001. Foram realizados três cultivos sucessivos de milho, com os seguintes tratamentos: testemunha absoluta; adubação mineral (NPK) recomendada para a cultura do milho, lodo de esgoto com base no teor de N para fornecer uma, duas, quatro e oito vezes a dose de N da adubação mineral. Avaliaram-se os teores totais (digestão nítrico-perclórica) de Cu, Mn, Ni, Pb e Zn em folhas e grãos de milho. A aplicação sucessiva dos lodos de esgoto acarretou aumento nos teores de Mn e Zn em folhas e grãos de milho. Em relação ao tratamento testemunha, a aplicação da dose mais elevada do LB (8LB) promoveu um incremento de até 270 e 625 % e de 35 e 115 % nos teores de Mn e Zn, respectivamente, nas folhas e grãos de milho. As folhas apresentaram maiores teores de metais pesados do que os grãos, o que envolve maior possibilidade de transferência de metais para a cadeia alimentar, caso essa parte da planta seja consumida. Essa elevação nos teores de metais pesados em folhas e grãos de milho, até à terceira aplicação dos lodos, não foi suficiente para atingir os níveis considerados fitotóxicos para o milho, tampouco para inviabilizar o uso dos grãos para o consumo humano.Sewage sludge is an important source of nutrients for crops, although the heavy metal contents can limit its use in agricultural soils. The objective of this study was to evaluate the effects of doses of sewage sludge (from the Treatment Stations of Barueri (LB) and Franca (LF), São Paulo State, Brazil) on heavy metal concentration in corn leaves and grains. The experiment was carried out at the Experimental Area of the Embrapa Environment, in Jaguariúna, state of São Paulo, from 1999 to 2001. The following treatments were applied to three successive corn crops: control (no sewage sludge); mineral fertilization recommended for corn (NPK); application of sewage sludge corresponding to the supply of one, two, four and eight times the N applied in the NPK treatment. The total contents (nitric-perchloric digestion) of Cu, Mn, Ni, Pb and Zn were measured in corn leaves and grains. The successive application of sewage sludge caused increases in the Mn and Zn contents in corn leaves and grains. In relation to the control treatment, the application of the highest dose of LB (8LB) promoted an increment of up to 270 and 625 % of Mn, and 35 and 115 % of Zn concentration, respectively, in the corn leaves and grains. The corn leaves presented higher heavy metals contents than the grains, which implicate a greater possibility of metal transfer to the food chain in case this part of the plant is consumed. Until the third sludge application the heavy metal concentration observed in corn leaves were lower than the levels considered phytotoxic, and their concentration in corn grains were not high enough to make them unsuitable for human consumption.

Apesar do potencial para o uso agrícola de lodos de esgoto, seus conteúdos de metais pesados podem se tornar um fator limitante a esse uso. Este estudo teve como objetivo avaliar o efeito de diferentes fontes e doses de lodo de esgoto, oriundos das Estações de Tratamento de Esgoto de Barueri (LB), que trata esgoto doméstico e industrial, e de Franca (LF), que trata esgoto predominantemente doméstico, ambas localizadas no Estado de São Paulo, sobre os teores de metais pesados em solo e sobre a fitodisponibilidade desses elementos químicos para o milho. O experimento foi realizado entre os anos de 1999 e 2001, no Campo Experimental da Embrapa Meio Ambiente, em Jaguariúna (SP), em três cultivos sucessivos de milho, e estudados os seguintes tratamentos, para os dois lodos: testemunha absoluta; adubação mineral (NPK) recomendada para a cultura do milho; dose dos lodos de esgoto para fornecer uma, duas, quatro e oito vezes a dose de N do tratamento NPK. Foram determinados os teores totais (solo, folha e grão de milho) e disponíveis (solo) de Cu, Mn, Ni, Pb e Zn. O uso de doses crescentes do LB aumentou os teores disponíveis dos metais avaliados em solo, quando se utilizou a solução de DTPA. Os incrementos nos teores totais de metais pesados foram maiores nas parcelas adubadas com o LB. As soluções de Mehlich-1 e DTPA mostraram-se eficientes em predizer a fitodisponibilidade de Zn para o milho, quando as folhas e grãos foram analisados.This study carried out in order to evaluate the effect of sewage sludge (from Barueri: industrial and residential sewage, and Franca (SP) State: residential sewage) doses on soil heavy metal contents and their availability to corn. Three successive experiments were installed in a Latosol at the Experimental Field of Embrapa Environment, in Jaguariúna (SP), from 1999 to 2001. The treatments investigated consisted of: control (without sewage sludge); mineral fertilization (NPK) recommended for corn; and application of both sewage sludge sources to supply one, two, four and eight times the N dose applied in the NPK treatment. It was quantified the total (soil, leaf and grain) and available (DTPA and Mehlich-1) contents of Cu, Mn, Ni, Pb and Zn. Barueri sludge application increased the heavy metal contents extracted by DTPA solution. The total contents of heavy metals in soil are higher in plots fertilized with Barueri sewage sludge in relation to those quantified in areas treated with Franca sludge. When leaf and grain are analyzed, DTPA and Mehlich-1 solutions are effective in predicting the availability of Zn to corn plants.

Suppression of plant diseases due to the action of endophytic microorganisms has been demonstrated in several pathosystems. Experiments under controlled conditions involving endophytic bacteria isolated from leaves and branches of Coffea arabica L and Coffea robusta L were conducted with the objective of evaluating the inhibition of germination of Hemileia vastatrix Berk. & Br., race II, urediniospores and the control of coffee leaf rust development in tests with leaf discs, detached leaves, and on potted seedling of cv. Mundo Novo. The endophytic bacterial isolates tested proved to be effective in inhibiting urediniospore germination and/or rust development, with values above 50%, although the results obtained in urediniospore germination tests were inferior to the treatment with fungicide propiconazole. Endophytic isolates TG4-Ia, TF2-IIc, TF9-Ia, TG11-IIa, and TF7-IIa, demonstrated better coffee leaf rust control in leaf discs, detached leaves, and coffee plant tests. The endophytic isolates TG4-Ia and TF9-Ia were identified as Bacillus lentimorbus Dutky and Bacillus cereus Frank. & Frank., respectively. Some endophytic bacterial isolates were effective in controlling the coffee leaf rust, although some increased the severity of the disease. Even though a relatively small number of endophytic bacteria were tested, promising results were obtained regarding the efficiency of coffee leaf rust biocontrol. These selected agents appears to be an alternative for future replacement of chemical fungicide.Supressão de doenças de plantas por microrganismos endofíticos tem sido demonstrada em diversos patossistemas. Neste trabalho foram selecionados isolados de bactérias endofíticas de folhas e ramos de cafeeiro com potencial para o controle biológico da ferrugem do cafeeiro, pois é conhecido que esses microrganismos podem possuir essa característica. Bactérias endofíticas isoladas previamente de folhas e ramos de Coffea arabica L e Coffea robusta L foram avaliadas quanto ao seu potencial de biocontrole da ferrugem do café causada pelo fungo Hemileia vastatrix Berk. & Br., raça 2. As bactérias foram testadas para a inibição da germinação de urediniosporos do fungo e em bioensaios para o controle do desenvolvimento da ferrugem alaranjada do cafeeiro em discos de folhas, folhas destacadas e mudas da cv. Mundo Novo. Os isolados de bactérias endofíticas testados demonstraram eficácia na inibição da germinação de urediniosporos e/ou no desenvolvimento da ferrugem, com valores acima de 50%, embora os resultados obtidos nos testes de germinação de urediniosporos tenham sido inferiores ao tratamento com propiconazole (testemunha padrão). Nos testes em discos de folhas, folhas destacadas e em plantas de cafeeiro, os isolados endofíticos TG4-Ia, TF2-IIc, TF9-Ia, TG11-IIa e TF7-IIa demonstraram melhor controle da ferrugem do cafeeiro. Os isolados endofíticos TG4-Ia e TF9-Ia foram identificados como Bacillus lentimorbus Dutky e Bacillus cereus Frank. & Frank., respectivamente. De acordo com os resultados verifica-se que alguns isolados foram eficientes em controlar a ferrugem do cafeeiro, embora alguns tenham aumentado a severidade da doença. Apesar do número relativamente baixo de bactérias endofíticas testadas, resultados promissores foram obtidos em relação ao controle biológico da ferrugem, sendo que esses poderão no futuro apresentar uma alternativa aos fungicidas.

O lodo de esgoto, atendendo às exigências ambientais, apresenta grande potencial para utilização em solos agrícolas, onde vem sendo amplamente disposto. Sua utilização altera propriedades químicas, físicas e biológicas do solo, devido a sua composição em macro e micronutrientes e matéria orgânica. Estas alterações podem proporcionar benefícios como aumento da disponibilidade nutricional às culturas, indução de supressividade aos fitopatógenos presentes no solo e resistência às doenças da parte aérea. Por outro lado, pode influenciar negativamente o equilíbrio biológico e químico no solo, devido à presença de concentrações consideráveis de N disponível, sais solúveis e metais pesados. Com o objetivo de avaliar os efeitos da incorporação de lodo de esgoto ao solo sobre supressividade de nematoides de galha (Meloydogine javanica (Treub) Chitwood) e do cisto (Hetodera glycines Ichinoe), parasitas da soja (Glycine max L.), foram realizados experimentos em laboratório e casa de vegetação utilizando-se solo coletado de área experimental da Embrapa Meio Ambiente, Jaguariúna, SP. Esta área recebeu aplicações sucessivas de lodos de esgotos, originários das Estações de Tratamento de Esgoto de Barueri e de Franca, no Estado de S. Paulo, durante cinco anos (1998-2002). Com relação à indução de supressividade a nematóides, observou-se que o lodo de esgoto não afetou o desenvolvimento de fêmeas de H. glycines no solo (apenas reduziu o número de ovos por cisto) contudo reduziu a reprodução de M. javanica, nas raízes de soja.Sewage sludge has shown great potential for use in agriculture, where it has been widely used. There are some modifications on chemical, physical and biological properties of the soil due to its composition of macro and micronutrients and organic substances. These alterations can provide benefits as an increase to the availability of nutrients to the plants, suppressiveness induction of soilborne plant pathogens and resistance to foliar diseases. However, it may influence negatively the biological and chemical balance in the soil, due to the presence of considerable amounts of available N, soluble salts and heavy metals. The aim of this work was to evaluate the effect of sewage sludge incorporation to the soil and the suppressiveness induction of nematodes (Meloydogine javanica (Treub) Chitwood and Heterodera glycines Ichinoe) in soybean (Glycine max L.). Experiments were performed in laboratory and in a greenhouse using collected soil in an experimental area of the Embrapa Meio Ambiente, Jaguariúna, SP. This area received successive applications of sewage sludge, originary from the sewage treatment of Barueri and Franca, in São Paulo State, Brazil, during five years (1998-2002). In relation to the suppressiveness induction of nematodes, the sludge did not affect significantly the development of H. glycines in the soil, but reduced the M. javanica reproduction, in the soybean root.

Among several alternative agricultural systems have been developed, organic agriculture has deserved increasing interest from. The objective of this paper was comparing both organic (OS) and conventional (CS) tomato cropping systems for varieties Débora and Santa Clara, through an interdisciplinary study. The experiment was set up in a randomized blocks design with six replicates, in a dystrophic Ultisol plots measuring 25 ´ 17 m. Cropping procedures followed by either local conventional or organic growers practices recommendations. Fertilization in the OS was done with organic compost, single superphosphate, dolomitic limes (5L, 60 g, and 60 g per pit), and sprayed twice a week with biofertilizer. Fertilization in the CS was done with 200 g 4-14-8 (NPK) per pit and, after planting, 30 g N, 33 g K and 10.5 g P per pit; from 52 days after planting forth, plants were sprayed once a week with foliar fertilizer. In the CS, a blend of insecticides, fungicides and miticides was sprayed twice a week, after planting. In the OS, extracts of black pepper, garlic, and Eucalyptus; Bordeaux mixture, and biofertilizer, were applied twice a week to control diseases and pests. Tomato spotted wilt was the most important disease in the OS, resulting in smaller plant development, number of flower clusters and yield. In the CS, the disease was kept under control, and the population of thrips, the virus vector, occurred at lower levels than in the OS. Variety Santa Clara presented greater incidence of the viral disease, and for this reason had a poorer performance than 'Débora', especially in the OS. Occurrence of Liriomyza spp. was significantly smaller in the OS, possibly because of the greater frequency of Chrysoperla. The CS had smaller incidence of leaf spots caused by Septoria lycopersici and Xanthomonas vesicatoria. However, early blight and fruit rot caused by Alternaria solani occurred in larger numbers. No differences were observed with regard to the communities of fungi and bacteria in the phylloplane, and to the occurrence of weeds.Diversos sistemas agrícolas alternativos têm sido desenvolvidos e, dentre eles, a agricultura orgânica tem recebido destaque, despertando interesse por parte dos agricultores. Compararam-se o sistema orgânico (SO) e o convencional (SC) de tomates da variedade Débora e Santa Clara, por meio de um estudo interdisciplinar. O experimento foi conduzido em blocos casualizados com seis repetições, com parcelas medindo 25 ´ 17 m, em um Argissolo Vermelho-Amarelo distrófico. Todas as práticas culturais foram realizadas de acordo com as técnicas utilizadas pelos agricultores convencionais ou orgânicos da região. No SO a fertilização foi realizada aplicando, em cada cova, composto orgânico, superfosfato simples e calcário dolomítico (5 L, 60 g e 60 g) e pulverizando biofertilizante duas vezes por semana. No SC, foi utilizado 200 g 4-14-8 (NPK) por cova e, após o plantio, 30 g N, 33 g K and 10,5 g P por cova; a partir de 52 dias após o plantio, as plantas foram pulverizadas com adubo foliar uma vez por semana. No SC, para o controle dos problemas fitossanitários, foram realizadas aplicações de mistura de inseticidas, fungicidas e acaricidas duas vezes por semana. Para o SO o controle foi realizado pulverizando-se extratos de pimenta-do-reino, de alho e de eucalipto; calda bordaleza e biofertilizante duas vezes por semana. O vira-cabeça foi a principal doença do SO, resultando em menor desenvolvimento de plantas, número de inflorescência e produção. No SC, a doença foi mantida sob controle, sendo que a população de tripes, vetor do vírus, ocorreu em níveis inferiores que no SO. A variedade Santa Clara apresentou maior incidência da virose e, por esse motivo, teve desempenho inferior à Débora, especialmente no SO. A ocorrência de Liriomysa spp. foi significativamente menor no SO, possivelmente devido à maior freqüência de Chrysoperla. O SC apresentou menor incidência de manchas foliares causadas por Septoria lycopersici e Xanthomonas vesicatoria, entretanto a pinta preta e a podridão de frutos causados por Alternaria solani ocorreram em maiores proporções. Não foram observadas diferenças quanto às comunidades de fungos e bactérias do filoplano e quanto à ocorrência de plantas invasoras.

Realizou-se este estudo com o objetivo de avaliar o efeito das aplicações sucessivas, em doses crescentes, de duas fontes de lodo de esgoto sobre os teores totais de Cu, Mn, Ni, Pb e Zn em solo, em três cultivos sucessivos de milho. O experimento foi conduzido no campo experimental da Embrapa Meio Ambiente, localizado em Jaguariúna-SP, durante os anos agrícolas 1999/2000 e 2000/2001, em Latossolo Vermelho Distroférrico. Os lodos utilizados no experimento foram obtidos nas Estações de Tratamento de Esgoto (ETEs) de Franca e Barueri. Os tratamentos, para cada fonte de lodo de esgoto, foram os seguintes: testemunha, sem adição de lodo de esgoto; NPK; aplicação de lodo de esgoto visando a suprir a quantidade de N normalmente requerida pelo milho; 2; 4 e 8 vezes a dose de lodo aplicada no tratamento 1N. As doses de lodo aplicadas (base seca) variaram de 0 a 139,24 Mg ha-1 para o lodo de Barueri e de 0 a 80,27 Mg ha-1 para o lodo de Franca. Avaliou-se o acúmulo de Cu, Mn, Ni, Pb e Zn pela determinação do teor total (água régia) desses metais no solo. Os teores totais de Cu e Zn em solo aumentaram com o acréscimo nas doses aplicadas das duas fontes de lodo; contudo, não foram verificados no solo teores totais dos metais pesados analisados acima dos valores estabelecidos em literatura para solos agrícolas.This study was designed to evaluate the effect of the successive applications i crescent doses, of two sources of sewage sludge on the total contents of Cu, Mn, Ni, Pb and Zn in soil, in three successive crops of corn. The experiment was conducted in the experimental field of Embrapa Environment, located in Jaguariúna in São Paulo state over the agricultural years of 1999/2000 and 2000/2001 in a Diostroferic Red Latosol. The sludges utilized in the experiment were obtained in the Sewage Treatment Stations (STSs) of Franca and Barueri. The treatments for each source of sewage sludge were the following: control, without addition of sewage sludge; NPK; application of sewage sludge aiming to supply the amount of N normally required by corn; 2, 4 and 8 times the rate of sludge applied in the 1N treatment. The rates of sludge applied (dry basis) ranged from 0 to 139.24 Mg ha-1 for Barueri sludge and from 0 to 80.27 Mg ha-1 for Franca sludge. The accumulation of Cu, Mn, Ni, Pb and Zn through the determination of the total content (regia water) of these metals in soil were evaluated. The total contents of soil Cu and Zn increased with the increment of applied doses of the two sludge sources, however, were not verified in soils, total contents of the heavy metals analyzed above the values established in literature for agricultural soils.

O objetivo deste trabalho foi avaliar o efeito da solarização do solo, associada à incorporação de lodo de esgoto, cama-de-frango e casca de Pinus, no controle de Pythium spp. Foram conduzidos dois ensaios, um em área cultivada comercialmente com crisântemo e outro em área artificialmente infestada com Pythium spp. em cultivo de pepino. A adição de cama-de-frango induziu a supressividade do solo ao patógeno, visto que resultou em maiores temperaturas no solo solarizado, aumento na condutividade elétrica e maior atividade microbiana do solo, avaliada pela hidrólise de diacetato de fluoresceína e desprendimento de CO2. Por outro lado, o lodo de esgoto e a casca de Pinus não induziram a supressividade ao patógeno. A solarização não teve efeito no crescimento da parte aérea e no peso de matéria fresca de raízes de plantas de crisântemo, mas teve efeito significativo no controle do patógeno no ensaio conduzido com pepino.

Despite the recent interest in organic agriculture, little research has been carried out in this area. Thus, the objective of this study was to compare, in a dystrophic Ultisol, the effects of organic and conventional agricultures on soil organism populations, for the tomato (Lycopersicum esculentum) and corn (Zea mays) crops. In general, it was found that fungus, bacterium and actinomycet populations counted by the number of colonies in the media, were similar for the two cropping systems. CO2 evolution during the cropping season was higher, up to the double for the organic agriculture system as compared to the conventional. The number of earthworms was about ten times higher in the organic system. There was no difference in the decomposition rate of organic matter of the two systems. In general, the number of microartropods was always higher in the organic plots in relation to the conventional ones, reflectining on the Shannon index diversity. The higher insect population belonged to the Collembola order, and in the case of mites, to the superfamily Oribatuloidea. Individuals of the groups Aranae, Chilopoda, Dyplopoda, Pauropoda, Protura and Symphyla were occasionally collected in similar number in both cropping systems.

O objetivo do trabalho foi verificar a ocorrência de sinergismo entre misturas de produtos alternativos aos fungicidas, para o controle do bolor verde (Penicillium digitatum) em pós-colheita de citros. Foram testados dez produtos individualmente e trinta e cinco combinações destes produtos dois a dois, em comparação com tiabendazole e testemunha, com e sem inoculação. Os produtos testados não apresentaram efeito de sinergismo, exceto a mistura carbonato de Na + ácido bórico. Carbonato de Na e ácido bórico controlaram a doença em 78 e 87%, respectivamente, e, utilizando a mistura, o controle foi de 93%. Destacaram-se, ainda no controle da doença, o bicarbonato de Na, metabissulfito de Na e as misturas de bicarbonato de sódio + ácido bórico, carbonato de Na + carbonato de K, carbonato de Na + sorbato de K, bicarbonato de Na + carbonato de Na, controlando 92; 77; 81; 77; 75 e 71%, respectivamente. O tiabendazole utilizado como padrão controlou totalmente a doença.The objective of this work was verify the ocurrence of synergism of mixtures for alternative products to the fungicides for the control of the green mold (Penicillium digitatum) in post-harvest citrus fruits. The efficiency of ten products, tested individually, and thirty five combinations among them, in pairs, were compared to thiabendazole and control, with and without inoculation. The products didn't present a synergism effect, except the mixture sodium carbonate + boric acid, that had a disease control of 93%. The products, sodium carbonate and boric acid controled 78 and 87%, respectively. The sodium bicarbonate, sodium methabisulphite and the mixtures of sodium bicarbonate + boric acid, sodium carbonate + potassium carbonate, sodium carbonate + potassium sorbate, sodium bicarbonate + sodium carbonate had a disease control of 92%, 77%, 81%, 77%, 75% and 71%, respectively. The fungicide treatment with thiabendazole used by standard had a whole disease control.

A descoberta do fungo Colletotrichum gloeosporioides parasitando cochonilha em pomares cítricos levantou a possibilidade de sua utilização no controle de Orthezia praelonga. O controle biológico, porém, deve ser feito com a certeza de que o microrganismo utilizado não ocasionará doenças em outras culturas. Este trabalho teve por objetivo avaliar e comparar o potencial fitopatogênico dos isolados de C. gloeosporioides patogênicos a O. praelonga, com outros isolados de C. gloeosporioides, C. acutatum e C. lagenarium, responsáveis pelas doenças de pós-colheita e podridão floral, em citros, e da antracnose, em abobrinha, respectivamente. Os fungos foram inoculados em banana, café, maçã, mamão, pêssego e folhas de abobrinha, com e sem ferimentos. Os pêssegos foram suscetíveis a todos os isolados testados, nas duas metodologias utilizadas. As maçãs e as folhas de abobrinha, quando lesadas, também mostraram suscetibilidade. A banana, o café e o mamão não foram suscetíveis em nenhum dos métodos de inoculação.The discovery of the fungus Colletotrichum gloeosporioides living like a parasite on the O. praelonga in citric orchards, raise the possibility of its utilization on the control of this pest. The biological control, however, should be done with the certainty that the utilized microorganism will not provoke diseases in other cultures that are been cultivated near the orchards. Then, this work aimed to evaluate and compare the phytopathogenic potential of the C. gloeosporioides isolates, pathogenics of O. praelonga (CTAA1-5), with other C. gloeosporioides isolates (CCC and CCE), C. acutatum (CCA) and C. lagenarium, responsible by diseases of fruit in citrus post-harvest and postbloom, and by antracnose in pumpkin, respectively. The fungi were inoculated on banana, coffee, apple, peach, papaya and on the pumpkin leaves, with or without injury. The peach fruits were susceptive to all isolates tested at the two experimental conditions. The apple and the pumpkin leaves, when injured, also showed susceptibility. The banana, coffee, and papaya were not susceptive in both inoculation conditions.

A long-term assay was conducted to evaluate the environmental impacts of agriculture use of sewage sludge on a tropical soil. This paper describes and discusses the results obtained by applying a interdisciplinary approach and the valuable insights gained. Experimental site was located in Jaguariúna (SP, Brazil). Multiyear comparison was developed with the application of sewage sludge obtained from wastewater treatment plants at Barueri (domestic and industrial sewage) and Franca (domestic sewage), São Paulo State. The treatments were control, mineral fertilization, and sewage sludge applied based on the N concentration that provides the same amount of N as in the mineral fertilization recommended for corn crop, two, four, and eight times the N recommended dosage. The results obtained indicated that the amount of sewage sludge used in agricultural areas must be calculated based on the N crop needs, and annual application must be avoided to prevent overapplications.