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

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

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

The Journey to R4D: An institutional history of an Australian Initiative on Food Security in Africa

Internal Revie

Simulation of Lablab Pastures

The potential of legume-based pastures to address declining soil nitrogen on marginal cropping soils is increasingly recognised in northern Australia, as such there is a need for cost benefit analysis of pastures and crops in a mixed farming system. In highly variable rainfall environments, biophysical modelling may be the best way of identifying and quantifying interactions with mixed crop-livestock systems on a seasonal basis. This paper describes a case study where both animal productivity and lablab pasture production is simulated. Lablab (Lablab purpureus) is an annual tropical legume widely used as a short-term legume phase in crop-pasture rotations, providing high quality forage for animal production and a low risk nitrogen input for crop production

Theoretical He I Emissivities in the Case B Approximation

We calculate the He I case B recombination cascade spectrum using improved radiative and collisional data. We present new emissivities over a range of electron temperatures and densities. The differences between our results and the current standard are large enough to have a significant effect not only on the interpretation of observed spectra of a wide variety of objects but also on determinations of the primordial helium abundance.Comment: Accepted to ApJ

Selection of Forages for the Tropics (SoFT) - A Database and Selection Tool for Identifying Forages Adapted to Local Conditions in the Tropics and Subtropics

Rising populations and incomes in developing countries are likely to double demand for livestock products by 2020 (Delgado et al. 1999). This strong demand has potential to improve profitability for farmers but will require improved animal feeding in both semi-intensive crop-livestock and more extensive livestock systems. Forages usually are the most cost-effective option to supply feed demands, particularly for ruminant-, but also for pig- and poultry- production. It is critical to select the most suitable forages for the local system and conditions. Small- and even larger-scale farmers depend heavily on advice from extension and development agencies, and from seed companies, but this advice often is limited by inexperience and the difficulty in accessing reliable information. Expert information on an extensive range of tropical forages is now readily available through the SoFT database

Intensity Mapping of Lyman-alpha Emission During the Epoch of Reionization

We calculate the absolute intensity and anisotropies of the Lyman-alpha radiation field present during the epoch of reionization. We consider emission from both galaxies and the intergalactic medium (IGM) and take into account the main contributions to the production of Lyman-alpha photons: recombinations, collisions, continuum emission from galaxies and scattering of Lyman-n photons in the IGM. We find that the emission from individual galaxies dominates over the IGM with a total Lyman-alpha intensity (times frequency) of about (1.43-3.57)x10^{-8} erg s^{-1} cm^{-2} sr^{-1} at a redshift of 7. This intensity level is low so it is unlikely that the Lyman-\alpha background during reionization can be established by an experiment aiming at an absolute background light measurement. Instead we consider Lyman-\alpha intensity mapping with the aim of measuring the anisotropy power spectrum which has rms fluctuations at the level of 1 x 10^{-16} [erg s^[-1} cm^{-2} sr^{-1}]^2 at a few Mpc scales. These anisotropies could be measured with a spectrometer at near-IR wavelengths from 0.9 to 1.4 \mu m with fields in the order of 0.5 to 1 sq. degrees. We recommend that existing ground-based programs using narrow band filters also pursue intensity fluctuations to study statistics on the spatial distribution of faint Lyman-\alpha emitters. We also discuss the cross-correlation signal with 21 cm experiments that probe HI in the IGM during reionization. A dedicated sub-orbital or space-based Lyman-\alpha intensity mapping experiment could provide a viable complimentary approach to probe reionization, when compared to 21 cm experiments, and is likely within experimental reach.Comment: 18 pages, 17 figure

Improving Predictions for Helium Emission Lines

We have combined the detailed He I recombination model of Smits with the collisional transitions of Sawey & Berrington in order to produce new accurate helium emissivities that include the effects of collisional excitation from both the 2 (3)S and 2 (1) S levels. We present a grid of emissivities for a range of temperature and densities along with analytical fits and error estimates. Fits accurate to within 1% are given for the emissivities of the brightest lines over a restricted range for estimates of primordial helium abundance. We characterize the analysis uncertainties associated with uncertainties in temperature, density, fitting functions, and input atomic data. We estimate that atomic data uncertainties alone may limit abundance estimates to an accuracy of 1.5%; systematic errors may be greater than this. This analysis uncertainty must be incorporated when attempting to make high accuracy estimates of the helium abundance. For example, in recent determinations of the primordial helium abundance, uncertainties in the input atomic data have been neglected.Comment: ApJ, accepte