Priscila de Oliveira

Adubação de cultivares de feijoeiro comum em várzeas tropicais

The bean crop has a high economic and social importance for the Brazilian population. However, some aspects should be improved in its cropping system, such as the plants fertilization management. The common bean sub-irrigation, in the rice intercropping, has been a viable alternative for grain yield, in the lowland ecosystem. However, there are just a few studies on fertilization in tropical lowland conditions. Thus, this study aimed at evaluating the yield of common bean cultivars grown under tropical lowland conditions and sub-irrigation, in Lagoa da Confusao, Tocantins State, Brazil, in the winter of 2008, by using different fertilizers sources, doses and splittings. The experimental design was randomized blocks, in a factorial scheme (cultivars x forms of fertilization), with cultivars divided into groups (black, carioca and special). The common bean yield was higher with the early nitrogen fertilization, and even higher when it was combined with potassium in topdressing fertilization, being the Ouro Negro (black group), Pitoco (carioca group) and Cranberry and BRS Embaixador (special group) the cultivars that reached the highest grain yields. When the recommended fertilization was used, Ouro Negro (black group), Carioca (carioca group) and Jalo Precoce and BRS Embaixador (special group) reached the highest grain yield, for each grain group. Yield was higher for the black group cultivars, when compared to the carioca and special groups.

Consórcio de milho com braquiária e guandu‑anão em sistema de dessecação parcial

The objective of this work was to assess the viability of maize (Zea mays) cultivar BRS 1035 intercropped with palisadegrass (Urochloa brizantha) and pigeon pea (Cajanus cajan) in the partial desiccation system. The experiments were performed in the summer season of 2008/2009, in Santo Antonio de Goias, GO and Ipameri, GO, Brazil, in a complete randomized block design, with five replicates. The treatments consisted of maize intercropped with palisadegrass and pigeon pea, with mineral nitrogen application on maize, on the day of its emergence, or 20 days after this event, with or without the application of a herbicide subdose on palisadegrass not desiccated. The viability of the partial desiccation system is dependent on the nitrogen fertilizer management of corn or on the growth control of nondesiccated palisadegrass rows.

Crescimento e produtividade de milho em função da cultura antecessora

The use of cover crops in the no-tillage system can provide better conditions for the development of maize plants, with positive effects on grain yield. By using the growth analysis technique, this study aimed at characterizing the agronomic performance of maize on common bean, Brachiaria brizantha and millet straw. The experiment was carried out in a Brazilian Savannah soil, in Santo Antonio de Goias, Goias State, Brazil. The experimental design was randomized complete blocks, with three treatments (cover crops) and five replications. The common bean straw decomposition rate was higher than the B. Brizantha and millet ones. The highest values for the dry matter accumulation of leaves, stems, cobs and total, as well as leaf area index and maize grain yield, were observed when cultivated on common bean straw.

Iron Content Affects Lipogenic Gene Expression in the Muscle of Nelore Beef Cattle

Iron (Fe) is an essential mineral for metabolism and plays a central role in a range of biochemical processes. Therefore, this study aimed to identify differentially expressed (DE) genes and metabolic pathways in Longissimus dorsi (LD) muscle from cattle with divergent iron content, as well as to investigate the likely role of these DE genes in biological processes underlying beef quality parameters. Samples for RNA extraction for sequencing and iron, copper, manganese, and zinc determination were collected from LD muscles at slaughter. Eight Nelore steers, with extreme genomic estimated breeding values for iron content (Fe-GEBV), were selected from a reference population of 373 animals. From the 49 annotated DE genes (FDR<0.05) found between the two groups, 18 were up-regulated and 31 down-regulated for the animals in the low Fe-GEBV group. The functional enrichment analyses identified several biological processes, such as lipid transport and metabolism, and cell growth. Lipid metabolism was the main pathway observed in the analysis of metabolic and canonical signaling pathways for the genes identified as DE, including the genes FASN, FABP4, and THRSP, which are functional candidates for beef quality, suggesting reduced lipogenic activities with lower iron content. Our results indicate metabolic pathways that are partially influenced by iron, contributing to a better understanding of its participation in skeletal muscle physiology.

Soybean growth and yield under cover crops

The use of cover crops in no-tillage systems can provide better conditions for the development of soybean plants with positive effects on grain yield and growth analysis techniques allow researchers to characterize and understand the behavior of soybean plants under different straw covers. Thus, the aim of this study was to characterize, using growth analysis, yield components and agronomic performance of soybean under common bean, Brachiaria brizantha and pearl millet straws. The experiment was performed on a soil under cerrado in the municipality of Santo Antonio de Goias, GO. The experiment was arranged in a randomized complete block design with three treatments (cover crops) and five replications. Soybean grain yield was lower in the B. brizantha straw treatment (3,708 kg ha -1 ) than both in the pearl millet (4.772 kg ha -1 ) and common bean straw treatments (5,200 kg ha -1 ). The soybean growth analysis in B. brizantha, pearl millet and common bean allowed characterizing the variation in the production of dry matter of leaves, stems, pods and total and leaf area index that provided different grain yields. The cover crop directly affects the soybean grain yield.

Corn and soybean yields as affected by cover crops and herbicide timing under no-tillage system

To achieve better results in the no-tillage system (NTS), it is important to properly manage the cover crop prior to planting by using herbicides, usually glyphosate. The effect of glyphosate on plant coverage is slow, and plants take a few days to die completely. Thus, when applying the herbicide on the same day of planting soybean or corn, cover crops are still alive and standing, causing initial shading on seedlings of the crop and delaying its establishment. Therefore, this study aimed to evaluate the effect of distinct cover crops and their timing of desiccation prior to planting soybean or corn, on crop yield and yield components. Two experiments were installed, one for soybean and another for corn. Each experiment consisted in combining three cover crops (Brachiaria brizantha, common bean or millet) chemically desiccated at two timings before planting the crop (15 or 0 days before planting) under no-tillage system (NTS). Experiments were installed in a completely randomized block design with five replications. Brachiaria brizantha produced the highest amount of biomass; common bean and millet as cover crops allowed higher soybean grain yields; herbicide application under common bean, millet and Brachiaria brizantha 15 days before planting soybean allowed higher crop grain yields; desiccation timing of common bean did not affect corn grain yield; Brachiaria brizantha should be desiccated 15 days before planting corn to allow maximum grain yield; when millet was used as a cover crop, glyphosate application at planting of corn allowed the highest grain yield.

Uso do solo e cultivares de arroz consorciados com braquiária no Cerrado

A avaliacao dos novos cultivares de arroz, em consorcio com o capim marandu (Urochloa brizantha cv. Marandu), no sistema de semeadura direta, podera possibilitar a identificacao de materiais mais adaptados a esse sistema, sem reducao da produtividade de graos da cultura. O objetivo deste trabalho foi avaliar a produtividade de cultivares de arroz de terras altas, em sistemas de cultivo solteiro e consorciado com capim marandu (Urochloa brizantha cv. Marandu), em dois sistemas de manejo do solo (convencional, PC, e sistema semeadura direta, SSD). O delineamento experimental foi em blocos ao acaso, no esquema fatorial 2 (sistemas de cultivo) x 2 (sistemas de manejo do solo) x 5 (cultivares). O experimento foi conduzido na regiao de Cerrado, no municipio de Ipameri-GO. O consorcio de cultivares de arroz de terras altas Primavera, BRSMG Curinga, Caiapo e BRS Bonanca com capim marandu nao afetou a produtividade de graos da cultura. Os cultivares de arroz Primavera, BRSMG Curinga e Caiapo podem ser cultivados, tanto no SSD quanto no PC sem afetar a produtividade de graos da cultura. A producao de biomassa seca do capim marandu foi afetada pelo consorcio com cultivares de arroz de terras altas.