This study aimed to evaluate the seasonal variation in concentrations of chlorophyll a, b, total chlorophyll and carotenoids in leaves of Hancornia speciosa, Gomes, during the periods of the year, relating them to the main phenological events, periods (rainy, dry and transitions) and populations evaluated. The survey was performed in three sites and the spatio-temporal analysis divided into four periods (rainy, rainy-drytransition, dry and dry-rainy transition), with 10 replicates (matrix plants). The data were collected in average intervals of 33 days from October 2014 to April 2017. The extraction and calculation of the chlorophyll and carotenoid contents of the leaves were expressed in mg/g DM, according to the equations of Arnon (1949) and Lichtenthaler (1987). There was a significant difference between the periods and sites analyzed for all pigments and their relationships. There was a greater amount of chlorophyll a than chlorophyll b; this difference was greater in the dry period. In the rainy period, we found a greater amount of total chlorophyll, carotenoids and total chlorophyll/carotenoid ratio. The behavior for the species follows that already observed for deciduous plants, closely related to water availability.
A fertirrigação é uma técnica de aplicação de nutrientes para plantas via água de irrigação. As águas residuárias domésticas (ARD) têm elevadas concentrações de nitrogênio (N), fósforo (P) e potássio (K), com isso surge a alternativa do reuso dessas águas como fonte de nutrientes no cultivo agrícola, reduzindo os impactos ambientes gerado por esse resíduo e diminuindo os custos na aquisição de adubos químicos na implantação das culturas. Contudo, as principais limitações do uso de ARD são a presença de sódio, e microrganismos coliformes fecais. Entretanto, estudos realizados na Universidade Federal de Tocantins têm demonstrado que o uso de ARD no solo do Cerrado para cultivo de capim tem baixo potencial de sanilização e sodificação do solo, sem alterações significativas nas propriedades físicas e químicas do solo e a biomassa vegetal não apresenta crescimento desses microrganismos. Assim, o objetivo desse estudo foi avaliar as alterações na fertilidade e na diversidade microbiana (bactérias fixadoras de nitrogênio e fungos micorrízicos) do solo do Cerrado após aplicação de ARD no cultivo de capim Brachiaria brizantha cv Marandu. Os manejos de irrigação utilizados continha 0, 20, 40 e 60 % (m/v) de fertilizantes NPK oriundos de ARD que foi aplicado após o crescimento da plântula. As composições químicas e a diversidade microbiana foram determinadas nas amostras do solo. Nas amostras da planta determinou-se a massa seca e o potencial nutricional do capim. A adição de ARD alterou a abundância bactérias e fungos, mas a diversidade não teve alterações. Esse resultado pode ser devido à maior disponibilidade de NPK no solo. Não foram observadas alterações na composição nutricional do capim após a fertirrigação. Portanto, a ARD tem potencial para ser utilizado na fertirrigação de capim em solo do Cerrado.
The biodiversity of the Cerrado has been threatened by the increase in agricultural production in the state of Tocantins and by the increased use of pesticides. This region of Formoso do Araguaia, it is home to around 1,825 indigenous people and is one of the largest indigenous territories in the state of Tocantins This work investigates the levels of pesticide residues in different environmental compartments (soil, sediment and water samples) of the Formoso River in the state of Tocantins, Brazil. The presence of pesticides of the imidazolinones and strobirulins classes by UHPLC-MS/MS were analyzed from April 2018 to February 2019, which helped in an evaluation of the impacts of pesticides on the biodiversity of the place of study. After analysis, five active principles (azoxystrobin, fenamidone, imazethapyr, tricyclazole, and trifloxystrobin) were detected in the water matrix, two active principles (azoxystrobin and tricyclazole) in the soil matrix, but no active principle was detected in the sediment matrix. In the region of the Parque do Araguaia Indigenous Lands, people who use this water for cultivation, hygiene and food, which is worrying, are exposed to these substances.
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