Compensating damage effects of seed-borne Fusarium culmorum and Microdochium nivale in winter wheat by increased seeding rates

Fusarium culmorum and Microdochium nivale are considered important seed-borne diseases of wheat in Denmark. Their damage effects consist in reducing seed germination and plant emergence which leads to reduced plant density, panicle numbers/area and yield. The aim of this study is to find out whether and to what degree these damage effects can be compensated by increased seeding rates. A trial was therefore conducted in 2004 in which seed lots of three winter wheat varities (Ritmo, Bill and Boston) having various degrees of infection by F. culmorum and Microdochium nivale were sown at various seeding rates. Seed contamination of the two pathogens was determined by counting the number of discoloured roots in the seed batches (Doyer method). Plant emergence was determined by counting the number of plants/area at seedling stage. A general linear model based on a term for [variety x pathogen] and a term for [variety x pathogen x germinating seeds/m2 x fraction of healthy seeds] explained ca. 70% of the variation in plant emergence. All parameters in the model were highly significant (p £ 0,005) and the R2 values of the individual variety x pathogen combinations ranged from 0.47 (Boston x M. nivale) to 0.85 (Ritmo x F. culmorum). The parameters of the model indicate that Boston was most responsive to an increasing seeding rate and/or healthy seed fraction, followed by Ritmo and Bill. This suggests that recommendations regarding the compensation of damage effects of seed-borne F. spp. and M. nivale by increasing seeding rates should be variety-specific. Supplemental results are expected from detailed analyses of the yield data and from an ongoing field trial. Further work will also include the development and use of molecular diagnostic tools to distinguish between various Fusarium spp. and M. nivale on contaminated seeds

Quantification of leaf stripe, Pyrenophora graminea, in barley seed by real-time PCR

In some years, large amounts of organic seed lots are discarded due to the presence of high levels of seed-borne diseases. In barley it is especially the presence of the fungal species Pyrenophora teres (barley net blotch) and P. graminea (barley leaf stripe), which causes rejection of seed lots. A real-time PCR method for detection and quantification of P. graminea has been developed

Factors impacting youth development in Haiti

Of the 1.6 million Haitian youth aged 15-24, only 13 percent are content with their lives. More than half of 20-year-olds have not completed secondary education and nearly half of youth in the labor market are unemployed. This paper investigates protective and risk factors predisposing youth to positive and negative behaviors. These factors, including poverty, gender, education, labor market, migration, family, health, and violence, are examined by using statistics and probability models based on Haiti's first household living conditions survey. Key findings show that female youth need special attention because they are more likely than their male peers to drop out of school and to be unemployed or inactive. Role models, guidance, expectations, and contacts in the form of parents or household heads are decisive factors in keeping youth in school, and to some extent, in their finding employment. In addition, domestic migration has a negative impact on the probability of being unemployed or inactive (positive self-selection), while marriage, drug abuse, and domestic violence increase the probability of dropping out of school.Youth and Governance,Adolescent Health,Population Policies,Primary Education,Education For All

Molecular diagnostic methods can prevent unnecessary rejection of organic seed lots

In some years, large amounts of organic seed lots are discarded due to the presence of high levels of seed-borne diseases. In barley it is especially the presence of the fungal species Pyrenophora teres (barley net blotch) and P. graminea (barley leaf stripe), which causes rejection of seed lots. A real-time PCR method for detection and quantification of P. graminea has been developed

The constitution of economic growth: Testing the prosperity effects of a Madisonian model on a panel of countries 1980‐2000

Political scientists and economists increasingly agree that institutions may influence economic growth, but there is little general agreement on what institutions tend to produce what consequences. We apply public choice insights for a theoretical analysis that may be termed “Madisonian”: Institutions that divide political power between multiple veto players and institutions that protect private property rights may be expected to have positive effects on economic growth. We analyze data from a panel of countries for the period 1980‐2000 in order to study the relationships, including a series of “extreme bounds” analyses in order to test the robustness of the statistical results. We find that particularly the presence of secure private property has a significant, positive and robust effect on economic growth and that when outliers are excluded a configuration where political power is dispersed among more veto players has a similar effect.Constitutions; democracy; economic growth; veto players; public choice; constitutional economics

Deep learning for video game playing

In this article, we review recent Deep Learning advances in the context of how they have been applied to play different types of video games such as first-person shooters, arcade games, and real-time strategy games. We analyze the unique requirements that different game genres pose to a deep learning system and highlight important open challenges in the context of applying these machine learning methods to video games, such as general game playing, dealing with extremely large decision spaces and sparse rewards