Lauri Lourenço Radünz's research while affiliated with Universidade Federal do Rio Grande do Sul and other places

The objective of this work was to study PAHs contamination in rice grains subjected to different milling types, after drying at different air temperatures in a direct-fired dryer and using firewood with different moisture contents as a heating source. In addition to verifying the persistence of these compounds after storage. Drying of rice grains was performed in a cross-flow dryer at air temperatures of 55 and 65 ºC. As heating source firewood containing different moisture contents was used. The presence of nine PAHs was detected. The drying air temperature, as well as the storage time, did not significantly influence the PAHs contamination of grains. The highest PAHs contamination was observed in grains from the brown subgroup. Grain polishing promoted a reduction in the PAH concentration. The grains subjected to parboilization showed a higher PAHs concentration. The use of firewood with higher moisture content promoted greater PAHs contamination in the grains.

O cultivo do mirtilo tem atraído atenção devido ao seu perfil bioativo, e potencial antioxidante, sendo que suas características produtivas influenciam no número e na qualidade dos frutos produzidos. O objetivo foi avaliar as características produtivas e sua influência no perfil físico-químico do mirtilo cv. Powderblue por dois anos. Observou-se maior número de botões florais intercalados com botões vegetativos no nível apical. Os primórdios florais foram encontrados em maior número nos níveis medial e apical do caule e influenciaram as posições de flores e frutos que foram encontrados em maior quantidade no nível apical do caule. Em ambas as safras, os frutos localizados no nível apical apresentaram maior teor de sólidos solúveis, compostos fenólicos, antocianinas, potencial antioxidante, pH e menor acidez do que os frutos localizados nos níveis mediano e basal. A posição dos botões florais e vegetativos impacta o nível e o número de primórdios florais, flores e frutos, e está diretamente relacionada à atividade antioxidante, compostos fenólicos totais, antocianinas totais e parâmetros físico-químicos dos frutos.

Corn crop, due to its easy adaptation to the most diverse agroecosystems, spreads throughout the different regions of the world, making it one of the most important agricultural crops. In this crop, pest insects stand out for causing losses both in the field and in warehouses. The application of essential oils can be an important technique to be investigated in the management of insects due to its known insecticidal activity and low risk to the environment. The objective of the work was to value the insecticide and repellent effect of essential oils of exotic lemongrass (Cymbopogon citratus) and native lemongrass (Elionurus sp.) for the management of maize weevil (Sitophilus zeamais (Mots., 1855, Coleoptera: Curculionidae)). The chemical analysis of the oils made by CG-MS showed that the chemical composition of the native and exotic lemongrass is similar, however, the exotic species presented a greater number of compounds. The essential oils of native and exotic lemon grass have efficiency on maize weevil mortality, and it is verified that the increase in the applied dose reflects in a reduction in the insect's exposure time for death to occur. The essential oil of both species showed repellent capacity at all times evaluated. Thus, it can be said that both species have the capacity and potential to be used in the management of corn weevil, and can be an alternative for smallhorders farmers and organic production.

Blueberry farming can be considered an excellent alternative to diversify the family income. In addition, the fruits have several health benefits thanks to the presence of phenolic compounds and anthocyanins, however blueberries chemical composition is affected by edaphoclimatic conditions and bud position within the shoot. Therefore, the objective of the study was to evaluate the influence of the bud position on the total phenolic content, anthocyanins, antioxidant capacity, and other quality parameters of blueberry fruits of three cultivars (Climax, Bluegem, and Powderblue) grown in the mesoregion of Pelotas, Brazil. Fruits of these cultivars were harvested from three shoot position. The fruits were evaluated for their total soluble solids content, pH, total titratable acidity, total soluble solids/total titratable acidity ratio, fruit color, phenolic compounds, anthocyanins, and antioxidant potential against the 2,2-diphenyl-1-picryl-hydrazyl radical. The bud position in the shoots influenced the physicochemical parameters of the blueberry fruits of all cultivars. Fruits harvested from apical levels had higher content of soluble solids, pH, phenolic compounds, anthocyanins, and antioxidant potential, demonstrating that studies aiming at evaluating fruits from different shoot levels are important, as they directly impact the quality of the fruits as well as their biological potentials. Keywords: climax; bluegem; powderblue; bud position; phytochemical

Maize is a cereal widely cultivated and consumed on the planet and, as an agricultural commodity, research strategies addressing productive bottlenecks are then highly appreciated. Among these, pest insects stand out for causing losses both in the field and in warehouses. Thus, thinking about the sustainability of the productive system, there is a need to develop more natural techniques for the management of insects, especially the application of essential oils. Among essential oils, thyme has proven bioactive potentials, however, its application is restricted due to its instability, and thus encapsulation may be a promising alternative for its preservation. In this context, the objective of this work was to evaluate the effect of the application of encapsulated and non-encapsulated thyme essential oil on the mortality and persistence of Sitophilus zeamais (Motschulsky, 1885) and on the quality parameters of corn grains throughout storage. Thyme essential oil was encapsulated by spray drying and evaluated for chemical composition and encapsulation efficiency. The effects of thyme essential oil application on the mortality and persistence of Sitophilus zeamais were evaluated for 150 days and on the quality of corn grains for 200 days. Insect mortality was dependent on concentration and exposure time, presenting the greatest effect for encapsulated thyme essential oil. Both oils, in all concentrations, showed repellent effect against S. zeamais, except for 1 h of exposure. The application of essential oils did not impact the water content, pH, leached solids, conductivity and staining of corn grains, however, treatments with application of encapsulated essential oil increased acidity and soluble solids content. The application of both thyme essential oils, encapsulated and non-encapsulated, were effective for the control of S. zeamais, without altering the quality characteristics of corn grains.

The concern with food security, aiming at food production without or with low use of pesticides, has been increasing in recent years. The use of pesticides requires necessary care during their application since they can generate several negative consequences for producers and consumers. Also, the incorrect use of these chemicals has caused problems, such as the emergence of resistance to pests and diseases, making it difficult to manage crops. It may even make production unfeasible, in addition to soil and water contamination. Several studies aiming at the alternative control of agricultural pests and diseases have found potential in plant sources, mainly through their essential oils and extracts. Salvia (Salvia officinalis L.) is a perennial shrub of the Lamiaceae family, widely used for medicinal and gastronomic purposes, however, due to the presence of (chemical) compounds in the essential oil and extracts of the species, with proven biological action (antibacterial, antifungal, insecticide and allelopathic), makes it an alternative for the control of agricultural pests and diseases. In this scenario, aiming to use natural options for chemical control, products extracted from species such as sage can help search for sustainable and ecologically correct agriculture. Through a bibliographic review, this chapter will aim to present an overview of the use and potential of essential oil and extracts of Salvia officinalis for the control of different pests and diseases in agriculture.

Due to the increase in consumption and the possibilities of exportation and industrialization, blueberry cultivation has been expanding in Brazil. Since Rabbiteye is one of the more cultivated groups of blueberries in Brazil, this study aimed to assess the productive characterization of the blueberry cultivar Bluegem, group Rabbiteye. Assessments were conducted with plants in full production during two harvest seasons. We collected data on the following variables: flower and vegetative bud distribution, open flowers and formed fruit in two different shoot lengths, and number of floral primordia. The results showed a greater number of vegetative buds and the intercalation between flower and vegetative buds in a proportion of 78% and 48% in long and short shoots, respectively. The number of total buds and the number of flower and vegetative buds were influenced by the harvest season and the shoot length. The number of floral primordia was influenced by the bud position on the shoot, but not by the harvest season. The number of flowers and fruits, in general, was greater in apical buds and in long shoots.

The objective with the work was to evaluate, during storage, the rice seeds physical and physiological quality, cultivar IRGA 424 RI, dried with different drying air temperatures. For such, rice seeds were harvested with a moisture content of 22%. Then, they were subjected to drying in a cross-flow dryer, operating in an intermittent system and using the 55 and 65 ºC drying air temperatures. After, samples containing 50 kg of seeds were stored in PP Woven Bags for 240 days. After drying and every 60 days, physical and physiological analyses were performed. The experiment was conducted under a completely randomized design, arranged in a split-plot scheme, with 4 replications. The physical quality, estimated by the seed hectoliter weight, decreased during storage, regardless of the drying air temperature. The germination percentage, as well as the vigor increased during storage, regardless of drying air temperature due to the dormancy overcoming process. The dry seeds with the highest drying air temperature showed less vigor throughout the storage, according to the cold test. The rice seeds drying with an air temperature of 65 ºC, promoted a higher drying speed and did not negatively influence the seeds physical and physiological quality, however, reduced the vigor.