Identification of gaps in sugarcane plantations using UAV images.

The objective of this study is to present a methodology for the detection and quantification of gaps formed during planting or growing of sugarcane crops. The use of UAV images for precision agriculture is relevant because it brings new possibilities for improving crop's productivity by feeding the producer with highly accurate data about the crop status

Diversidade genética estimada por meio de variáveis quantitativas e moleculares em acesso de coqueiro-gigante.

Anais do 1º Simpósio da Rede de Recursos Genéticos Vegetais do Nordeste (I RGVNE), Cruz das Almas, nov. 2013

The Exact Critical Bubble Free Energy and the Effectiveness of Effective Potential Approximations

To calculate the temperature at which a first-order cosmological phase transition occurs, one must calculate $F_c(T)$, the free energy of a critical bubble configuration. $F_c(T)$ is often approximated by the classical energy plus an integral over the bubble of the effective potential; one must choose a method for calculating the effective potential when $V''<0$. We test different effective potential approximations at one loop. The agreement is best if one pulls a factor of $\mu^4/T^4$ into the decay rate prefactor [where $\mu^2 = V''(\phi_f)$], and takes the real part of the effective potential in the region $V''<0$. We perform a similar analysis on the 1-dimensional kink.Comment: 11 pages plus 3 figures in jyTeX; CALT-68-188

Comparison of Bemisia tabaci infestation, virus infection, and yield in conventional and transgenic Bean golden mosaic virus-resistant common bean elite lines.

In Brazil, the Cowpea mild mottle virus vectored by Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae), is an emerging threat for common bean (Phaseolus vulgaris L.; Fabaceae), including genetically modified elite bean lines developed for resistance to the Bean golden mosaic virus. To investigate this interaction, we quantified the susceptibility of 10 Bean golden mosaic virus-resistant lines to Cowpea mild mottle virus infection in 2 regions in Brazil with natural incidence of viruliferous B. tabaci. In 2 field trials, B. tabaci established on all varieties, but showed preference for the conventional cultivars ?Pérola? and ?BRS Pontal? when compared with elite lines (averaging > 400 nymphs per leaflet, and > 97% infection rate in 1 study). However, whereas elite lines were resistant to Bean golden mosaic virus, all became infected with Cowpea mild mottle virus. Highest infection rates (19 to 99% infected plants) occurred in genetically modified elite lines derived from BRS Pontal versus Pérola (12 to 16%). When comparing seed yield, most elite lines outperformed their conventional recurrent parent. On average, elite lines achieved relative yield increases between 199 and 1,045%, and the varieties CNFCT 16205 and CNFCT 16210 were the most productive in our field trials. Our results showed that the use of common bean cultivars resistant to golden mosaic is an important tool within integrated management strategies for whiteflies and viruses. However, further studies are needed to elucidate the threat of Cowpea mild mottle virus and the nature of whitefly interactions between these different viruses

Large carbon sink potential of secondary forests in the Brazilian Amazon to mitigate climate change

Tropical secondary forests sequester carbon up to 20 times faster than old-growth forests. This rate does not capture spatial regrowth patterns due to environmental and disturbance drivers. Here we quantify the influence of such drivers on the rate and spatial patterns of regrowth in the Brazilian Amazon using satellite data. Carbon sequestration rates of young secondary forests (<20 years) in the west are ~60% higher (3.0 ± 1.0 Mg C ha−1 yr−1) compared to those in the east (1.3 ± 0.3 Mg C ha−1 yr−1). Disturbances reduce regrowth rates by 8–55%. The 2017 secondary forest carbon stock, of 294 Tg C, could be 8% higher by avoiding fires and repeated deforestation. Maintaining the 2017 secondary forest area has the potential to accumulate ~19.0 Tg C yr−1 until 2030, contributing ~5.5% to Brazil’s 2030 net emissions reduction target. Implementing legal mechanisms to protect and expand secondary forests whilst supporting old-growth conservation is, therefore, key to realising their potential as a nature-based climate solution

Feijão resistente ao mosaico-dourado.

O mosaico-dourado (BGMV) do feijoeiro-comum. Transmissão. Sintomas, danos e perdas. Detecção e identificação. Estratégias de controle do inseto vetor. Tecnologia RMD. Desenvolvimento. Biossegurança. Características agronômicas e de interesse do consumidor. Cultivares RMD e a rastreabilidade em campo. Programa de gestão responsável (PGR). Rastreabilidade na cadeia produtiva, segregação de produtos, comercialização e rotulagem. Tecnologia RMD como ferramenta para o manejo integrado da mosca-branca e viroses associadas. Manejo da mosca-branca e do BGMV com a tecnologia RMD. Outras viroses do feijoeiro transmitidas pela mosca branca. Cultivares RMD.bitstream/item/222011/1/CNPAF-circ-tec-91.pd