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The selection of wheat genotypes according to their drought tolerance is essential to off-season cultivation. The objective of this work was to characterize wheat genotypes through yield and components, morphological characteristics under water stress, and irrigated water use efficiency in the Cerrado region in Brazil. Genotypes were planted during the winters of 2016 and 2017 since there is no precipitation during this season and water levels can be measured. They were then submitted to four water regimes: WR1, WR2, WR3, and WR4, representing 100 %, 83 %, 50 %, and 30 % of evapotranspiration replacement. The following variables were evaluated: peduncle length (PL), number of ears m-2 (NE m-2), hectoliter weight (HW), thousand grain weight (TGW), drought resistance index (DRI), irrigated water use efficiency (IWUE) and yield. Most variables showed correlation with yield and can be a useful tool for breeding programs. PL and HW were best correlated with yield. BRS 264 (irrigated biotype) was productive in treatments receiving the greatest number of irrigation treatments. Given that WR1 registered the highest water level, it was not expected that the rainfed biotype (BR18) would show a higher yield than an irrigated biotype (BRS254). BRS404 (rainfed biotype) was the most productive under moderate stress treatment (WR3). Aliança (rainfed biotype) showed a higher yield under severe stress. Rainfed biotypes presented a higher DRI than the irrigated ones. These genotypes can be used as a reference in breeding programs under each water regime in which their performance was outstanding. None of the variables studied contributed to the selection of the most efficient wheat genotypes in the IWUE.

No abstract

Euterpe oleracea Mart. is a palm tree popularly known as açai, which is primarily found in northern Brazil. The açai's fruits contain anthocyanins, a class of polyphenols to which antioxidant properties have been attributed. The aim of this work was to develop O/W sunscreens emulsions containing açai glycolic extract (AGE) and to evaluate both their physical stability and photoprotective efficacy. Emulsions containing AGE and sunscreens were formulated using different types and concentrations of polymeric surfactant (acrylates/C 10-30 alkyl acrylate crosspolymer and sodium polyacrylate). The influence of two rheology modifiers (polyacrylamide (and) C13-14/isoparaffin (and) Laureth-7 and Carbomer) on the stability was also investigated. Physical stability was evaluated by preliminary and accelerated studies. Emulsions with 1.0% sodium polyacrylate were stable and exhibited non-newtonian pseudoplastic behavior and thixotropy. Photoprotective efficacy was evaluated by in vivo Sun Protection Factor (SPF) and determination of Protection Factor of UVA (PF-UVA). When AGE was added to the sunscreen emulsion, no significant increase in the in vivo SPF value was observed. The emulsion containing AGE showed PF-UVA = 14.97, 1.69 of the SPF/PF-UVA ratio and a critical wavelength value of 378 nm, and may therefore be considered a sunscreen with UVA and UVB protection. Euterpe oleracea Mart. é uma palmeira popularmente conhecida como açaí, encontrada no norte do Brasil. O fruto do açaí apresenta em sua composição antocianinas, uma classe de polifenóis à qual é atribuída propriedade antioxidante. Os objetivos desse trabalho foram desenvolver emulsões fotoprotetoras O/A contendo extrato glicólico de açaí (AGE), avaliar a estabilidade física e avaliar a eficácia fotoprotetora. Emulsões contendo AGE e filtros solares foram formuladas utilizando diferentes tipos e concentrações de tensoativo polimérico (acrilates/C 10-30 alquil acrilato polímero cruzado e polilacrilato sódico). A influência de dois modificadores reológicos (poliacrilamida (e) C13-14/isoparafina (e) Laureth-7 e Carbomer) na estabilidade foi avaliada. A estabilidade física das emulsões foi avaliada por meio de estudos de estabilidade preliminar e acelerada. Emulsões com 1,0% poliacrilato sódico foram estáveis, exibiram comportamento não-newtoniano pseudoplástico e tixotrópico. A eficácia fotoprotetora foi avaliada pelo teste in vivo de Fator de Proteção Solar (FPS) e pela determinação do Fator de Proteção UVA (FP-UVA). Quando adicionado o AGE na emulsão contendo filtros solares, não se observou aumento significativo no valor do FPS. A emulsão contendo o AGE apresentou FP-UVA=14,97, a razão FPS/ FP-UVA = 1,69 e o comprimento de onda crítico igual a 378 nm, podendo ser considerado um protetor solar com proteção UVA e UVB. Unitermos:Emulsão O/A/desenvolvimento. Euterpe oleracea/farmacognosia. Euterpe oleracea/extrato glicólico/eficácia fotoprotetora. Protetores Solares/desenvolvimento. Fator de Proteção Solar.

The objective of this study was to evaluate the effects of cover crops grown under no-tillage on the aggregation and physical protection of organic matter in soil macro and microaggregates. The experiment consisted of a randomized complete block design with three replications. The following cover crops were investigated in corn rotation systems: T1 = Braquiária ruziziensis (Urochloa ruziziensis), T2 = Canavalia brasiliensis Mart. ex Benth.,Br.], T5 = turnip-forage (Raphanus sativus L.), T6 = velvet bean (Mucuna aterrima Merr.) and T7 = native Cerrado vegetation as a reference environment. Soil was sampled at a depth of 0-10 cm in September 2015 for the determination of organic matter fractions in macro and microaggregates. There was a reduction in aggregate size and its stability when native Cerrado areas were converted into agricultural systems. Nevertheless, some cover crops such as velvet bean, millet and turnip-forage favored restructuring the soil, forming stable aggregates similar to the native Cerrado. Among the cover crops, millet was highlighted as presenting elevated capacity to accumulate labile organic carbon in macroaggregates (2.32 g C kg -1 ) and microaggregates (2.34 g C kg -1 ). These values are, on average, 60% higher than those presented by turnip-forage. In general, the conversion of land use under Cerrado vegetation to agroecosystems reduced the total organic carbon content, mainly due to macroaggregate breakup, resulting in a lower physical protection of soil organic matter.