Can an agricultural 'commodity' be de-commodified, and if so who is to gain?

The weakness of redistributional mechanisms, both globally and within developing economies, makes it imperative to directly enhance the productive incomes of poor people. Coffee farmers, generally located in the poorest countries, have suffered especially badly in recent years, and farm gate and internationally traded bean prices are now at historically low levels. At the same time, though, global coffee consumers are becoming more discerning. With at least as much potential taste variety as in the case of wine, final product prices are becoming more differentiated. Margins for some coffees can therefore be expected to increase significantly as consumers become more discriminating in their tastes. But who is to gain from these more differentiated prices? Analysis shows that whilst the price spread is growing in global trading markets, it is simultaneously narrowing at the farm gate. At the same time, the destruction of coffee marketing boards (largely as a result of Structural Adjustment Programmes) has had unintended effects: instead of their margins accruing to farmers, almost all of these margins are being absorbed in the high-income importing countries. Thus, left to market forces, the likelihood is that farmers will gain little from increasingly discriminating final consumer tastes. Instead it is the global branders and the supermarket chains who are likely to appropriate these growing product rents. However, if consumers can be educated to recognise that better coffees are directly linked to their place of origin rather than to their brand names, a more equal global distribution of income is likely to emerge in this value chain. This paper ends with a discussion of which stakeholders may be involved in educating final consumer tastes in an appropriate manner

Ribosomal small subunit sequence diversity of Scutellospora within single spores and roots of bluebell from a woodland community.

Roots of bluebell (Hyacinthoides nonscripta) were sampled from a woodland in Yorkshire,UK and spores of an arbuscular mycorrhizal fungus Scutellospora sp., were obtained from the surrounding soil. Partial small subunit (SSU) ribosomal RNA sequences were amplified from both roots and spores using either the universal forward primer SS38 or the Glomales-specific primer VANS1, with the reverse Gigasporaceaespecific primer VAGIGA. Amplified products were cloned and sequenced. Both spores and roots yielded sequences related to those known from fungi within the Glomales,with up to four distinct SSU sequences obtained from individual spores. The VANS1 primer-binding site varied considerably in sequence and only a subset of Scutellospora sequences were amplified when the VANS1 primer was used. In addition to glomalean sequences, a number of different sequences, apparently from ascomycetes, were obtained from both root and spore samples

Phosphorus nutrition of ectomycorrhizal and arbuscular mycorrhizal tree seedlings from a lowland tropical rain forest in Korup National Park, Cameroon

The relationship between mycorrhizal colonisation and phosphorus acquired by seedlings of the arbuscular mycorrhizal tree Oubanguia alata Bak f. (Scytopetalaceae) and the ectomycorrhizal tree Tetraberlinia moreliana Aubr. (Caesalpiniodeae) was evaluated at low and high inorganic phosphorus availability. AM colonisation was positively correlated with phosphorus uptake by O. alata at low, but not at high phosphorus availability. Seedlings growth was positively related to arbuscular mycorrhizal colonisation at both low and high phosphorus availability, suggesting that growth promotion by arbuscular mycorrhizas is not simply related to an increase of phosphorus uptake. In contrast, phosphorus uptake by T. moreliana was correlated with EM colonisation at both low and high phosphorus availability, but there was no relationship between growth and ectomycorrhizal colonisation. Promotion of phosphorus uptake by arbuscular mycorrhizas and ectomycorrhizas at low phosphorus availability is consistent with the co-occurrence of the two types of mycorrhiza in tropical rain forests where available soil phosphorus is low. However, ectomycorrhizal colonisation may also be of advantage where inputs of phosphorus rich litter raise the phosphorus status of the soil, as seen in the groves of ectomycorrhizal trees in Korup National Park, and may be one of the factors reinforcing local dominance by these trees

An arbuscular mycorrhizal fungus accelerates decomposition and acquires nitrogen directly from organic material

Arbuscular mycorrhizal fungi (order Glomales), which form mycorrhizal symbioses with two out of three of all plant species, are believed to be obligate biotrophs that are wholly dependent on the plant partner for their carbon supply. It is thought that they possess no degradative capability and that they are unable to decompose complex organic molecules, the form in which most soil nutrients occur. Earlier suggestions that they could exist saprotrophically were based on observation of hyphal proliferation on organic materials. In contrast, other mycorrhizal types have been shown to acquire nitrogen directly from organic sources. Here we show that the arbuscular mycorrhizal symbiosis can both enhance decomposition of and increase nitrogen capture from complex organic material (grass leaves) in soil. Hyphal growth of the fungal partner was increased in the presence of the organic material, independently of the host plant

Root system architecture determines fitness in an Arabidopsis mutant in competition for immobile phosphate ions but not for nitrate ions

Plant root systems often have complex branching patterns. Models indicate that a complex architecture is only required for the acquisition of immobile resources, such as phosphate; mobile ions, notably nitrate, can be effectively taken up by very restricted root systems. We have tested this prediction using the axr4 mutation of Arabidopsis thaliana, the principal phenotypic effect of which is to reduce the number of lateral roots. Arabidopsis thaliana is not a host for mycorrhizal fungi and so acquires all its nutrients through the root system. In both a pot experiment and a field experiment conducted under natural conditions for A. thaliana, we found that only phosphate, and not nitrate, affected the fitness of the mutant relative to the isogenic wild-type line, Columbia. These results confirm model predictions and have implications both for the evolution of complex root systems and for the design of efficient root systems for crops

Ceylon on the road to long-term decline?

Since the day of independence the Administration of Ceylon has tried by a great number of measures to cope with the country’s social and economic problems. But the much desired change for the better has not been realised so far. On the contrary: There are many indications of a threatening collapse in Ceylon’s economy

Rapid turnover of hyphae of mycorrhizal fungi determined by AMS microanalysis of C-14

Processes in the soil remain among the least well-characterized components of the carbon cycle. Arbuscular mycorrhizal (AM) fungi are ubiquitous root symbionts in many terrestrial ecosystems and account for a large fraction of photosynthate in a wide range of ecosystems; they therefore play a key role in the terrestrial carbon cycle. A large part of the fungal mycelium is outside the root ( the extraradical mycelium, ERM) and, because of the dispersed growth pattern and the small diameter of the hyphae (<5 micrometers), exceptionally difficult to study quantitatively. Critically, the longevity of these. ne hyphae has never been measured, although it is assumed to be short. To quantify carbon turnover in these hyphae, we exposed mycorrhizal plants to fossil ("carbon-14 - dead") carbon dioxide and collected samples of ERM hyphae ( up to 116 micrograms) over the following 29 days. Analyses of their carbon-14 content by accelerator mass spectrometry (AMS) showed that most ERM hyphae of AM fungi live, on average, 5 to 6 days. This high turnover rate reveals a large and rapid mycorrhizal pathway of carbon in the soil carbon cycle