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Tropical and plantation crops include important crops for food security and alternative energy resources. Even so, there are few studies on the impact of climate change on diseases of these crops. Findings from previous studies concerning some climate-change effects on diseases of coffee, sugarcane, eucalyptus, cassava, citrus, banana, pineapple, cashew, coconut and papaya have been summarized to provide a context. By reviewing available methods to evaluate the impact of climate change on diseases of tropical and plantation crops, we present trends for some diseases and their management strategies, identify critical gaps in knowledge, and suggest experimental and analytical approaches to advance knowledge. As the projected climate conditions will probably vary greatly in the future from continent to continent and from developed to developing countries, studies must be conducted under tropical regions considering their specific environmental conditions. Multifactor studies under realistic field situations, such as free air CO 2 enrichment with increasing CO 2 and O 3 concentrations incorporating spectral reflectance measures in situ for realistic assessment of plant growth, are a way forward. Effects of a changing climate on chemical and biological controls are discussed in the context of changing global outlook on environmental demands for the future.

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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 CO 2 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. Key words: CO 2 , global climate change, global warming, spatial analysis, control MUDANÇAS CLIMÁTICAS E DOENÇAS DE PLANTASRESUMO: 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 CO 2 atmosférico e outros gases são discutidos importantes aspectos do comportamento das doe...

Despite the importance of coffee as a globally traded commodity and increasing concerns about risks associated with climate change, there is virtually no information about the effects of rising atmospheric [CO 2 ] on field-grown coffee trees. This study shows the results of the first 2 years of an innovative experiment. Two commercial coffee cultivars (Catuaí and Obatã) were grown using the first free-air CO 2 enrichment (FACE) facility in Latin America (ClimapestFACE). Plants of both cultivars maintained relatively high photosynthetic rates, water-use efficiency, increased growth and yield under elevated [CO 2 ]. Harvestable crop yields increased 14.6 % for Catuaí and 12.0 % for Obatã. Leaf N content was lower in Obatã (5.2 %) grown under elevated [CO 2 ] than under ambient [CO 2 ]; N content was unresponsive to elevated [CO 2 ] in Catuaí. Under elevated [CO 2 ] reduced incidence of leaf miners (Leucoptera coffeella) occurred on both coffee cultivars during periods of high infestation. The percentage of leaves with parasitized and predated mines increased when leaf miner infestation was high, but there was no effect of elevated [CO 2 ] on the incidence of natural enemies. The incidence of rust (Hemileia vastatrix) and Cercospora leaf spot (Cercospora coffeicola) was low during the trial, with maximum values of 5.8 and 1 %, respectively, and there Climatic Change was no significant effect of [CO 2 ] treatments on disease incidence. The fungal community associated with mycotoxins was not affected by the treatments.

The antagonistic activity against in vitro growth of Fusarium oxysporum f.sp. ciceris was determined for 74 bacterial isolates obtained from the rhizosphere of chickpeas grown in two field soils with different histories of Fusarium wilt, and for seven isolates of Pseudomonas spp. from culture collections. 1\venty-four isolates of Bacillus spp. and Pseudomonas chlororaphis 30-84 showed a strong antagonism against three races (0, 1 and 5) of F.o. ciceris tested. Three selected Bacillus isolates and P. chlororaphis 30-84 were further tested against 30 isolates of races O, 1 and 5 of F.o. ciceris, races O, 1 and 2 of F.o. melonis, F.o. phaseoli and nonpathogenic F. oxysporum. Bacillus isolates differed in their antagonistic activity and were less inhibitory to mycelial growth of F.o. eiceris than to that of other fungai isolates. Furthermore, the extent of growth inhibition of F.o. ciceris was influenced both by bacterial isolates and by race of the pathogen. Cell-free culture filtrates of four Bacillus isolates inhibited conidial germination and hyphal growth of F.o. ciceris and nonpathogenic F. oxysporum. Joint seed+soil treatment with some selected antagonistic Bacillus spp. isolates suppressed disease caused by the highly virulent F.o. ciceris race-5 in cv. ICCV 4 and cv. PV 61 chickpeas. However, the degree o f protection was influenced by the host genotype and the inoculum concentration of the pathogen.

Plants have evolved effective mechanisms to avoid or reduce the potential damage caused by abiotic stresses. In addition to biocontrol abilities, Trichoderma genus fungi promote growth and alleviate the adverse effects caused by saline stress in plants. Morphological, physiological, and molecular changes were analyzed in salt-stressed tomato plants grown under greenhouse conditions in order to investigate the effects of chemical and biological fertilizations. The application of Trichoderma harzianum T34 to tomato seeds had very positive effects on plant growth, independently of chemical fertilization. The application of salt stress significantly changed the parameters related to growth and gas-exchange rates in tomato plants subject to chemical fertilization. However, the gas-exchange parameters were not affected in unfertilized plants under the same moderate saline stress. The combined application of T34 and salt significantly reduced the fresh and dry weights of NPK-fertilized plants, while the opposite effects were detected when no chemical fertilization was applied. Decaying symptoms were observed in salt-stressed and chemically fertilized plants previously treated with T34. This damaged phenotype was linked to significantly higher intercellular CO2 and slight increases in stomatal conductance and transpiration, and to the deregulation of phytohormone networking in terms of significantly lower expression levels of the salt overlay sensitivity 1 (SOS1) gene, and the genes involved in signaling abscisic acid-, ethylene-, and salicylic acid-dependent pathways and ROS production, in comparison with those observed in salt-challenged NPK-fertilized plants.

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