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Planaltina, Brazil

Souza G.A.,Cornell University | Souza G.A.,Federal University of Lavras | Hart J.J.,Cornell University | Carvalho J.G.,Federal University of Lavras | And 5 more authors.
Plant Science | Year: 2014

Exploration of genetic resources for micronutrient concentrations facilitates the breeding of nutrient-dense crops, which is increasingly seen as an additional, sustainable strategy to combat global micronutrient deficiency. In this work, we evaluated genotypic variation in grain nutrient concentrations of 20 Brazil wheat (Triticum aestivum L.) accessions in response to zinc (Zn) and Zn plus selenium (Se) treatment. Zn and Se concentrations in grains exhibited 2- and 1.5-fold difference, respectively, between these wheat accessions. A variation of up to 3-fold enhancement of grain Zn concentration was observed when additionally Zn was supplied, indicating a wide range capacity of the wheat lines in accumulating Zn in grains. Moreover, grain Zn concentration was further enhanced in some lines following supply of Zn plus Se, showing stimulative effect by Se and the feasibility of simultaneous biofortification of Zn and Se in grains of some wheat lines. In addition, Se supply with Zn improved the accumulation of another important micronutrient, iron (Fe), in grains of half of these wheat lines, suggesting a beneficial role of simultaneous biofortification of Zn with Se. The significant diversity in these wheat accessions offers genetic potential for developing cultivars with better ability to accumulate important micronutrients in grains. © 2014. Source

de Souza G.A.,Cornell University | de Souza G.A.,Federal University of Lavras | de Carvalho J.G.,Federal University of Lavras | Rutzke M.,Cornell University | And 3 more authors.
Plant Science | Year: 2013

Micronutrients are essential for human health and crucial for plant survival. The capacity of food crops in acquiring mineral nutrients affects plant growth and potentially the yield and nutrient content in edible tissues/organs. In this study, we selected 20 wheat (Triticum aestivum L.) accessions and evaluated genotypic variations of the young seedlings in response to iron (Fe), zinc (Zn), and selenium (Se) treatments. Wheat accessions exhibited different growth responses to these minerals and possessed various abilities to accumulate them. Wheat seedlings in general were less tolerable to excess of Fe and benefits from increased levels of Zn supply. They were sensitive to selenite and profited from selenate treatment at low dosages. Limited mineral interactions were observed between Fe or Zn with other nutrients. In contrast, selenate supply enhanced Fe, Zn, sulfur (S), molybdenum (Mo), magnesium (Mg), calcium (Ca) and manganese (Mn) content in wheat seedlings, supporting its beneficial role in promoting plant growth; Selenite supplement reduced Zn, S, Mo, Mg, Ca and Mn levels in the plants, consisting with its detrimental role in inhibiting seedling growth. Based on nutrient accumulation, plant growth, and mineral interaction, a number of accessions such as EMB 38 and BRS 264 appeared to be good lines for breeding wheat cultivars with better plant health and potential to accumulate essential micronutrients in edible grains. © 2013. Source

Bastos C.S.,University of Brasilia | Torres J.B.,Federal Rural University of Pernambuco | Suinaga F.A.,Embrapa Cerrados CPAC
Journal of Applied Entomology | Year: 2010

Release of natural enemies in commercial fields is challenging and has been inconsistent in the results achieved. This work discusses the augmentative releases of Trichogramma pretiosum to control the cotton leafworm (CLW) Alabama argillacea and also examines the parasitoid-host interaction under grower field conditions. The treatments consisted of fields with and without releases of T. pretiosum set up in Primavera do Leste and Campo Verde Counties, MT, Brazil, during three different seasons (2003 and 2004 dry and 2004 regular summer seasons). Trichogramma wasps were weekly released in the treated fields throughout the entire sampling period (14-15 week period) at a rate of 100 000 wasps per hectare. One-way repeated measures analysis of variance was performed for the number of parasitized eggs, followed by a meta-analysis procedure to determine the contribution of T. pretiosum release on overall parasitism. In addition, regression analysis was conducted with each season's data sets to study the relationship of the host density and parasitism response by T. pretiosum. The overall results of Trichogramma augmentative releases did not result in significant increase of CLW egg parasitism beyond the natural parasitism in the areas studied. However, based on Cohen's d effect sizes from the meta-analysis, the parasitism rate was greater in fields under T. pretiosum releases during four out of 15 weeks surveyed. The parasitism of CLW eggs by T. pretiosum exhibited host density-dependence only in one out of three seasons surveyed. These findings are encouraging as they are evidence that T. pretiosum is able to maintain a considerable level of parasitism under commercial field conditions, highlighting their potential value in large-scale commercial areas of cotton as previously found at the small and diverse farming scale. Future studies should address the potential of early-season, low density releases of the parasitoid. © 2009 Blackwell Verlag, GmbH. Source

Rinaldi M.M.,Embrapa Cerrados CPAC BR 020 | Vieira E.A.,Embrapa Cerrados CPAC | De Freitas Fialho J.,Embrapa Cerrados CPAC | Malaquias J.V.,Embrapa Cerrados CPAC
Brazilian Journal of Food Technology | Year: 2015

The physical-chemical, sensory and microbiological characteristics during storage of cassava roots subjected to different freezing methods were evaluated. The roots were physically characterized, processed, packaged in LDPE packages with 100 μm of thickness and subjected to different treatments: freezing and storage at -18°C; freezing and storage at -80°C; and freezing with liquid nitrogen and storage at -80°C. The storage period was 31 days. The product subjected to all treatments had acceptable levels of pH, titratable acidity, soluble solids, ratio, ascorbic acid and time for cooking as well as the counting of evaluated microorganisms. In treatments freezing and storage at -18°C, freezing with liquid nitrogen and storage at -80°C cassava roots were sensory accepted throughout the storage. Despite the good results presented in storage of cassava roots subjected to freezing with liquid nitrogen and storage at -80°C, further studies are suggested regarding requirements and costs for the use of this technology at the producer level. The temperature of -18°C is sufficient to keep the product with appropriate characteristics for at least 31 days. Source

Pinto A.C.Q.,University of Brasilia | Neto F.P.,Embrapa Semi arido CPATSA | Guimaraes T.G.,Embrapa Cerrados CPAC
Revista Brasileira de Fruticultura | Year: 2011

Brazil is one of the largest mango producers in the world with 1,3 millions of tones from an area of 72,5 hectares. Nevertheless, the mango exports in 2010 was about 140 thousand tones which is approximately 10% of the total production. The diversification of mango supply to the internal and external markets has been done since the fresh mango from conventional production to the organic fruit from a specific management and also, most recently, there is a tendency for an increase demand of processed mango. To comply with these demands there is not only a need for the development of the processing industry, but also the improvement of mango cultivars and management techniques to attend the several exigencies of the market for conventional fresh, organic and processed fruits. This paper has the objective to suggest to the mango breeders efficient strategies to get and select the so called "ideal mango cultivar" as well as to discuss more efficient management techniques to attend the high production and quality of mango as an answer to the dynamic of the internal and external market demands. Source

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