This study aimed to evaluate the effects of potassium fertilization on Myracrodruon urundeuva, Libidibia ferrea and Mimosa tenuiflora seedlings submitted to a short period of water deficit. Three doses of K (0, 150 and 300 mg dm-3 KCl) and three water regimes (without water deficit, moderate water deficit and severe water deficit) were evaluated. The plants were kept in black plastic bags containing soil from the Caatinga and, 30 days after the beginning of the water regimes, the relative water content (RWC), transpiration (E), stomatal conductance (gs) and photosynthesis (A) were evaluated. High moisture content in the soil was unfavorable to plants, promoting reduction in RWC and gas exchange. The water deficit increase E, gs and A, but the intensity of these responses was variable between species. The water deficit favored L. ferrea, with elevated RWC and reduced alterations in gas exchange, demonstrating its greater tolerance in relation to the others species evaluated, however it was the species most benefited by K. The supply of 300 mg dm-3 of KCl positively influenced the water status and gas exchange of the studied species with an increase in the water deficit. We suggest the development of research subjecting the plants to a longer period of time, in order to establish a better relationship between potassium and the increased tolerance of these plants to water deficit.

Uma forma de minimizar os problemas ambientais ocasionados pelo crescimento desordenados das cidades é arborização urbana que pode proporcionar benefícios como, por exemplo, conforto térmico e redução da poluição sonora. Foram aplicados 150 formulários semiestruturados. A aplicação dos formulários se deu de forma sistemática, onde os mesmos foram divididos entre seis ruas do Distrito de Iara-CE. Os dados obtidos indicaram que 24,0% dos entrevistados consideram a localidade pouco arborizada, 64% acham que a arborização existente nesta localidade é razoável e 12,0% consideram muito arborizada. Quanto ao manejo da arborização, 85,0% dos entrevistados opinaram que a responsabilidade é da prefeitura, 33% opinaram que a responsabilidade é da própria população e 7% opinaram que o manejo da arborização urbana é de responsabilidade das companhias elétricas. As principais vantagens da arborização urbana indicadas foram: sombra 96,7%, redução na temperatura 61,3% e beleza estética 52% e as principais desvantagens foram redução na iluminação pública 56%, sujeira de ruas e calçadas 48,7% e problemas com redes elétrica e telefônica 42,0%. A análise da percepção ambiental dos moradores do Distrito de Iara mostrou que mais da metade dos entrevistados desconheciam o significado do termo arborização urbana, no entanto compreendem os benefícios proporcionado pelas árvores na localidade.

ABTRACT: For decades, chemical products have shown efficiency in inhibiting pathogens associated with forest seeds, but due to the high cost and environmental impact caused by it, research to find more viable and sustainable alternatives has been Held. The objective of this work was to evaluate the efficiency of Cinnamomum zeylanicum Blume extract in the treatment of seeds of Schinopsis brasiliensis Engl. And to indicate the use of plant extracts as an alternative for the control of pathogens associated with Forest seeds. For the sanity test, 500 seeds collected in 2010 and 500 seeds collected in the year 2014 submitted to treatments with cinnamon extract were used in the following concentrations: T1: solution containing 100% sterile water (control); T2: Solution containing 25% of cinnamon extract and 75% of sterile water; T3: Solution containing 50% cinnamon extract and 50% of sterile water; T4: Solution containing 75% of cinnamon extract and 25% of sterile water; T5: Solution containing 100% of cinnamon extract. The health test lasted 10 days and after this period, the pathogen was evaluated, associated with the seeds of S. Brasiliensis, through the observations of the fungal structures through a stereoscopic and optic microscope, and the help of the literature Specialized. The means were analyzed by the Tukey test at the level of 5% probability and the percentage values for the purposes of statistical analysis were transformed into arcsen√x/100.The treatment with solution containing 100% of cinnamon extract presented as the most efficient being the most suitable for the inhibition of pathogens associated with the forest seeds. Considering the results, we recommend the advancement of researches around the use of plant extracts as a solution for the treatment of forest seeds so that it becomes a viable alternative in the forestry sector. KEYWORDS: seeds, pathogens.

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