Combining High Yields and Blast Resistance in Rice (Oryza spp.): A Screening under Upland and Lowland Conditions in Benin

The future security of the supply of rice for food in Africa depends on improving the level of local production to achieve self-sufficiency. In order to cope with the existing gap between production and actual demand, combining a high level of rice blast tolerance and a high-yield potential is necessary. The current study was conducted under upland and lowland conditions in Benin to gain insight into the performance of selected blast-resistant accessions along with some currently grown varieties. This study revealed a high phenotypic variability among these accessions. Furthermore, differences in the performance of these accessions under lowland and upland conditions were observed. Principal component analysis showed their grouping in three clusters. The analysis also demonstrated a high yield potential among the blast-resistant rice accessions whether they were Oryza sativa or O. glaberrima. Furthermore, there was a significant correlation between yield and both spikelet fertility and growth cycle duration. In conclusion, the present study identified promising rice accessions for future breeding. High phenotypic variability in combination with interesting traits can help to develop new resilient varieties. Finally, when the traits correlate with yield, they can be used as markers for an early screening method for identifying promising accessions at an early stage

Deoxynivalenol content in wheat dust versus wheat grain: a comparative study

The present study, set up in the growing season 2011-2012, was designed to obtain quantitative data on the occurrence of deoxynivalenol in wheat grain and the corresponding wheat dust. The field experiment consisted of a complete randomised block design with five wheat varieties sown on a field on which maize was grown in the previous season. The impact of the tillage method and the influence of the wheat variety resistance on the deoxynivalenol content of wheat and wheat dust were investigated. The accumulation of deoxynivalenol in wheat dust was confirmed and a sigmoidal relationship between the deoxynivalenol content in wheat dust versus wheat grain was determined. Deoxynivalenol reduction was obtained by ploughing and by sowing moderately resistant wheat varieties. As wheat dust provides equal results and solves the problem of heterogeneity during sampling of conventional wheat matrix, the sampling of wheat dust can be considered as a promising alternative

Straw yield and quality: An extra motivation for the introduction of triticale in mixed farming systems**

Straw is a valuable by-product from cereal production. It is used for agricultural purposes as feed and bedding material for livestock. Additionally, cereal straw is a resource for the production of sustainable biomaterials and bio-energy. To meet the demands of these sectors substantial amounts of straw, with specific properties (e.g. water-holding capacity), are necessary. Since wheat breeding has mainly focused on grain yield rather than on straw yield other cereal species, such as triticale, can be of interest. Therefore, in this research the straw yield and water-holding capacity of four winter wheat and four winter triticale varieties were studied during two growing seasons. For both wheat and triticale there were differences in dry matter yield and percentage dry matter between growing seasons. Furthermore, depending on the growing season, there were significant differences in straw yield between the different wheat and triticale varieties. However, during both growing seasons, the straw yield obtained from the triticale varieties was significantly higher compared to the straw yield obtained from the wheat varieties. Concerning the water-holding capacity, it was concluded that the water absorption potential of triticale straw was higher compared to the water absorption potential of wheat straw. However, only in 2014 a significant difference between wheat and triticale was noted. So, it can be concluded that, besides the known advantages of triticale (performance on marginal soils, disease resistance, low fertilizer input, etc.), this crop has the potential to deliver high yields of high quality straw

III-V/silicon first order distributed feedback lasers integrated on SOI waveguide circuits

Heterogeneously integrated III-V-on-silicon first order distributed feedback lasers utilizing an ultra-thin DVS-BCB die-to-wafer bonding process are reported. A novel design exploiting high confinement in the active waveguide is demonstrated. 5 mW output power coupled to a silicon waveguide, 40 dB side mode suppression ratio and continuous wave operation up to 60°C is obtained

III-V/Silicon First Order Distributed Feedback Lasers Integrated on SOI Waveguide Circuits

Heterogeneously integrated III-V-on-silicon first order distributed feedback lasers utilizing an ultra-thin DVS-BCB die-to-wafer bonding process are reported. A novel design exploiting high confinement in the active waveguide is demonstrated. 5 mW output power coupled to a silicon waveguide, 40 dB side mode suppression ratio and continuous wave operation up to 60°C is obtained

Modelling credit spreads with time volatility, skewness, and kurtosis

This paper seeks to identify the macroeconomic and financial factors that drive credit spreads on bond indices in the US credit market. To overcome the idiosyncratic nature of credit spread data reflected in time varying volatility, skewness and thick tails, it proposes asymmetric GARCH models with alternative probability density functions. The results show that credit spread changes are mainly explained by the interest rate and interest rate volatility, the slope of the yield curve, stock market returns and volatility, the state of liquidity in the corporate bond market and, a heretofore overlooked variable, the foreign exchange rate. They also confirm that the asymmetric GARCH models and Student-t distributions are systematically superior to the conventional GARCH model and the normal distribution in in-sample and out-of-sample testing