ABSTRACT
Gypsum plays a prominent role in agriculture, being considered an effective alternative to alleviate subsurface acidity due to its higher solubility and containing sulfur. However, another significant aspect is which pose long-term risks of groundwater contamination due to excessive applications of salts, pesticides, and other chemicals that will be leached, or even soil chemical depletion. So far, no study has focused on understanding the impacts of the atmospheric gypsum plume originating from gibbsite mining and processing on the leaching of soil bases and chemical degradation surrounding these sites. In this study, we evaluated the behavior of chemical characteristics in soil profiles distributed along the dispersion of the atmospheric plume and in areas without interference from the industrial sector in the state of Maranhão, Northeast Brazil. Fifty-three sampling points were collected at 7 locations based on the dispersion of the dust plume through wind drift. Each sampling point was represented by three composite soil samples at depths of 0.0-0.20, 0.40-0.60, and 1.00-1.20 m, where the chemical soil characteristics were evaluated. The average levels of Ca, Mg, and K in the studied layers are classified as low, with minimum values below the method's detection limit, and they also show imbalance due to higher concentrations of Ca in the surface layer in areas affected by atmospheric dispersion. The sum and saturation of bases at all depths are classified as low. Higher aluminum saturation values were observed in the deeper soil layers. The gypsum dust altered the soil's chemical characteristics at the evaluated depths; therefore, it is necessary to seek means to mitigate gypsum dust release during gibbsite extraction and processing and ensure that the soils in areas near these enterprises maintain their natural characteristics.
ABSTRACT
The physicochemical characteristics of honey vary according to bee species, climate, region, period of collection, processing and storage. In this context, this work aimed to perform a comparative study of the physicochemical characteristics of Melipona subnitida and M. fasciculata honey collected at different periods and regions of the State of Piauí, Brazil. Twenty-nine honey samples were collected and evaluated by principal component analysis from physicochemical analysis data. Twenty-two percent of the parameters analyzed differed between species. Evaluating the collection period, the honey of M. subnitida and M. fasciculata presented differences among themselves. The study revealed a similarity between the physicochemical parameters of the honey of the two species of bees, in addition, the time was one of the determining factors in the formation of clusters.
Subject(s)
Bees/metabolism , Honey/analysis , Animals , Brazil , Chemical Phenomena , Droughts , Species SpecificityABSTRACT
The occurrence of the sugarcane weevil Sphenophorus levis Vaurie is important in sugarcane in some regions in Brazil. Damage is caused by the larvae as they bore into the nodes and can reach 30 ton/ha/year. Many control alternatives have been attempted, but none were satisfactory, except for the use of toxic baits. Therefore, it is necessary to optimize their efficiency or to propose new techniques. The objective of the current study was to evaluate the attractiveness of adults of S. levis to sugarcane nodes and pineapple peelings in an 'Y' tube olfactometer. The sugarcane internodes were treated with 10% molasses, and tested after different periods of fermentation (24, 48 e 72h), at different times of the day (diurnal and nocturnal) and with both sexes. These tests were carried out in order to correlate the response of S. levis to ethyl acetate and ethanol release as a result of the fermentation process. The release of both compounds was monitored by gas chromatography-mass spectrometry (GC-MS). Our data indicated that sugarcane internodes mixed with 10% molasses fermented for 24h and 48h were the most attractive to S. levis (up to 90%). Pineapple peelings attracted 62.5% of the tested insects. The olfactory response was higher during the day, and no differences were found between the sexes. The production of ethanol in all plant substrates was higher than ethyl acetate, but we could not establish a clear correlation with the insect response to baits.
Subject(s)
Appetitive Behavior , Smell/physiology , Weevils/physiology , Age Factors , Ananas , Animals , Female , Fermentation , Male , SaccharumABSTRACT
The occurrence of the sugarcane weevil Sphenophorus levis Vaurie is important in sugarcane in some regions in Brazil. Damage is caused by the larvae as they bore into the nodes and can reach 30 ton/ha/year. Many control alternatives have been attempted, but none were satisfactory, except for the use of toxic baits. Therefore, it is necessary to optimize their efficiency or to propose new techniques. The objective of the current study was to evaluate the attractiveness of adults of S. levis to sugarcane nodes and pineapple peelings in an "Y" tube olfactometer. The sugarcane internodes were treated with 10 percent molasses, and tested after different periods of fermentation (24, 48 e 72h), at different times of the day (diurnal and nocturnal) and with both sexes. These tests were carried out in order to correlate the response of S. levis to ethyl acetate and ethanol release as a result of the fermentation process. The release of both compounds was monitored by gas chromatography-mass spectrometry (GC-MS). Our data indicated that sugarcane internodes mixed with 10 percent molasses fermented for 24h and 48h were the most attractive to S. levis (up to 90 percent). Pineapple peelings attracted 62.5 percent of the tested insects. The olfactory response was higher during the day, and no differences were found between the sexes. The production of ethanol in all plant substrates was higher than ethyl acetate, but we could not establish a clear correlation with the insect response to baits.
A ocorrência do besouro da cana-de-açúcar, Sphenophorus levis Vaurie, é importante em algumas regiões do Brasil. O dano é causado pelas larvas que perfuram os colmos, ocasionando perdas de até 30 ton /ha/ano. Várias alternativas de controle têm sido utilizadas, embora nenhuma delas com resultados satisfatórios, à exceção do uso de iscas tóxicas. Sendo assim, há necessidade de otimizar sua eficiência ou propor novas técnicas. O objetivo do presente estudo foi avaliar a atratividade dos adultos de S. levis a toletes de cana e casca de abacaxi por meio de olfatômetro em "Y". Os entrenós foram tratados com melaço a 10 por cento e foram testados depois de diferentes tempos de fermentação (24, 48 e 72h), em diferentes horários (diurno e noturno) para ambos os sexos. Os testes foram conduzidos na tentativa de relacionar a resposta de S. levis ao acetato de etila e etanol produzidos pela fermentação. A produção de ambos compostos foi determinada por cromatografia gasosa de massa (GC-MS). Os dados obtidos indicaram que os entrenós da cana-de-açúcar misturados com melaço a 10 por cento e fermentados por 24h e 48h foram os mais atrativos a S. levis (acima de 90 por cento). A casca de abacaxi só atraiu 62,5 por cento dos insetos testados. A resposta olfativa foi maior durante o dia e não houve diferenças entre os sexos. A produção de etanol em todos os substratos foi maior do que a do acetato de etila, embora não tenha sido possível estabelecer uma relação clara com a resposta dos insetos às iscas.