Future Generations – Will Any Be Lacking Tropical Forage Genetic Resources?

It’s high time to stop talking about the (forage) plants and talk about the people. Three (Australia, India, USA) of the about a dozen curators of tropical and subtropical forage (TSTF) genetic resources collections involved in developing a Global Strategy on Conservation and Utilization of Tropical and Subtropical Forage Genetic Resources on behalf of the Global Crop Diversity Trust in 2015 have since retired. In all cases their replacements were not expert in this challenging commodity. Why? The commodity is highly diverse and requires understanding of a substantial body of knowledge generated over more than five decades. It requires a level of familiarity with two plant families, grasses and legumes, which comprise a plethora of genera and species. Some of these species, novel to agriculture, have been proven extremely useful for diverse livestock production systems, for environmental services and for people’s livelihoods. Others are rather ‘bycatch’ from early exploration and probably don’t deserve conservation at all, or at least at the highestgenebank standards. Why were there no mentored scientists waiting to take up the vacant positions? There is today a worldwide shortage of applied plant research capability as “–omic sciences” or modelling seem more appealing to emerging scientists. Few budding agricultural scientists want to dedicate their career to a commodity, which mostly ranks low in recognition of its science merits and funding support. At the same time forage science and forages are coming under greater scrutiny because of environmental factors, especially in relation to the impacts livestock production is having on global warming. However, there are emerging scientists wanting to build a career in tropical forage science. Unfortunately, they are often disconnected from similar work around the world, and their own work is insufficiently recognizedby aging, inward-looking institutions that still claim to lead global forage research and development despite the ever declining resources

Tropical Forage Genetic Resources -- Will Any Be Left for Future Generations?

After very active years of pasture and forage research at major institutes, interest in tropical forage genetic resources has drastically declined. Apparently, the early phases of collecting and evaluation were much more valued than conserving and keeping the germplasm available for future generations. Accumulated data are not easily accessible and, therefore, the knowledge of tropical forage genetic resources is progressively being lost. This worldwide decrease in activity and loss of knowledge is due to declining resources. It is suggested that a global database on tropical forage genetic resources should be established and also that finances be made available to at least maintain collections at their current reduced level

Rebuilding a Tropical Forages for the Future Network – A Call for Resuscitating Enthusiasm for a Commodity with Great Prospects and Innovation Potential

A series of Forages for the Future newsletters, outlining some of the latest tropical and subtropical forage (TSTF) research and development impacts and expertise, has been published since 2016. Amongst the research highlights were Brazilian scientists’ focus on grasses such as Urochloa, Megathyrsus maximus, Paspalum and Cenchrus purpureus, and on legumes, especially Arachis and Stylosanthes. Argentinian researchers are similarly targeting Acroceras macrum and Setaria sphacelata; while Indian and ILRI (East Africa) researchers are using plant breeding to overcome disease constraints in Napier grass (Cenchrus purpureus and associated hybrids). Also demonstrated were successfully using genetic resources of Desmanthus, Leucaena leucocephala and Macroptilium bracteatum to improve Australian livestock production in varying farming systems on heavy-textured soils. Amongst the most innovative forage-based development outcomes featured in the newsletters were the increasing role of Mucuna pruriens in crop-livestock systems of semi-arid Zimbabwe, and the enabling role that forage grasses and legumes play in the icipe-developed “push-pull”-system to control a range of pests in African maize farming-systems. Some common threads stand out in these impact-delivering programs: longevity and ongoing institutional support, clear end-user focus, deep understanding of species adaptation and their phenotypic diversity and, how various species and ecotypes might be used. These are just some of the successful research-for-development programs taking place across the tropics and subtropics; they provide an opportunity for strengthening TSTF research and development into the future. One missing ingredient is opportunity for teams from national, international centres and from the private sector to meet regularly to exchange results, ideas and challenges. International conferences and similar forums are expensive and too infrequent; but online options offer new communication approaches. The IGC in Nairobi is the perfect opportunity to discuss possible new collaboration forums and, if required, how they might operate to make for a better, well-informed and innovative international TSTF network

Origin of the World\u27s Collection of the Tropical Forage Legume Chamaecrista Rotundifolia

Round leaf cassia (Chamaecrista rotundifolia) cv. Wynn is an important legume in light textured soils in sub-tropical Queensland and forage evaluators in other regions of the tropics frequently wish to include in their evaluation trials this cultivar plus other accessions which represent the variation in the species. Provenance data of a world collection of 130 accessions of round leaf cassia were examined and a core set of 26 accessions selected

Simple Lattice-Models of Ion Conduction: Counter Ion Model vs. Random Energy Model

The role of Coulomb interaction between the mobile particles in ionic conductors is still under debate. To clarify this aspect we perform Monte Carlo simulations on two simple lattice models (Counter Ion Model and Random Energy Model) which contain Coulomb interaction between the positively charged mobile particles, moving on a static disordered energy landscape. We find that the nature of static disorder plays an important role if one wishes to explore the impact of Coulomb interaction on the microscopic dynamics. This Coulomb type interaction impedes the dynamics in the Random Energy Model, but enhances dynamics in the Counter Ion Model in the relevant parameter range.Comment: To be published in Phys. Rev.

Time-Dependent Density Functional Theory for Driven Lattice Gas Systems with Interactions

We present a new method to describe the kinetics of driven lattice gases with particle-particle interactions beyond hard-core exclusions. The method is based on the time-dependent density functional theory for lattice systems and allows one to set up closed evolution equations for mean site occupation numbers in a systematic manner. Application of the method to a totally asymmetric site exclusion process with nearest-neighbor interactions yields predictions for the current-density relation in the bulk, the phase diagram of non-equilibrium steady states and the time evolution of density profiles that are in good agreement with results from kinetic Monte Carlo simulations.Comment: 11 pages, 3 figure

Influence of external magnetic fields on growth of alloy nanoclusters

Kinetic Monte Carlo simulations are performed to study the influence of external magnetic fields on the growth of magnetic fcc binary alloy nanoclusters with perpendicular magnetic anisotropy. The underlying kinetic model is designed to describe essential structural and magnetic properties of CoPt_3-type clusters grown on a weakly interacting substrate through molecular beam epitaxy. The results suggest that perpendicular magnetic anisotropy can be enhanced when the field is applied during growth. For equilibrium bulk systems a significant shift of the onset temperature for L1_2 ordering is found, in agreement with predictions from Landau theory. Stronger field induced effects can be expected for magnetic fcc-alloys undergoing L1_0 ordering.Comment: 10 pages, 3 figure

Hopping Transport in the Presence of Site Energy Disorder: Temperature and Concentration Scaling of Conductivity Spectra

Recent measurements on ion conducting glasses have revealed that conductivity spectra for various temperatures and ionic concentrations can be superimposed onto a common master curve by an appropriate rescaling of the conductivity and frequency. In order to understand the origin of the observed scaling behavior, we investigate by Monte Carlo simulations the diffusion of particles in a lattice with site energy disorder for a wide range of both temperatures and concentrations. While the model can account for the changes in ionic activation energies upon changing the concentration, it in general yields conductivity spectra that exhibit no scaling behavior. However, for typical concentrations and sufficiently low temperatures, a fairly good data collapse is obtained analogous to that found in experiment.Comment: 6 pages, 4 figure

Classical Driven Transport in Open Systems with Particle Interactions and General Couplings to Reservoirs

We study nonequilibrium steady states of lattice gases with nearest-neighbor interactions that are driven between two reservoirs. Density profiles in these systems exhibit oscillations close to the reservoirs. We demonstrate that an approach based on time-dependent density functional theory copes with these oscillations and predicts phase diagrams of bulk densities to a good approximation under arbitrary boundary-reservoir couplings. The minimum or maximum current principles can be applied only for specific bulk-adapted couplings. We show that they generally fail to give the correct topology of phase diagrams but can still be useful for getting insight into the mutual arrangement of different phases.Comment: 4 pages, 3 figure