A methodological approach for the on-site quantification of food losses in primary production: Austrian and German case studies using the example of potato harvest.

In the last decade, in many European Countries more and more measures have been initiated aiming at the prevention of food losses and wastes along the entire value chain. In order to evaluate or monitor such important measures it is crucial to obtain quantitative information on generated food waste amounts, subsequently enabling the quantitative evaluation of the measure's outcomes and efficiency. Currently there is a paucity of quantitative information, particularly on food losses that are directly generated during harvesting processes. Up to date, no method is available or standardised aiming at the in-situ or on-site quantification of food losses during harvest. Using the example of the potato harvest, this study presents a practical approach for determining potato losses. To test the applicability of the developed method, on-site measurements were conducted directly on the field at five different locations in Austria and Germany. Our method enables the quantification of food losses based on defined areas along the harvested potato rows, where the analyser manually collects potatoes during their harvest. Hereby, two types of potato losses needs to be considered: non-harvested, under-sized potatoes that remain under the earth and the harvested ones, which are rejected on-site because of quality requirements regarding their size, shape, and state of health. Our study shows that between 1 and 9% of field losses (based on yield potential) can be generated during the potato harvest. In future, this method may be the basis for standardised protocols in order to be able to derive cultivar-specific benchmarks and, consequently, to develop measures for preventing food losses. In general, more case studies and evidence-based ground-up measurements on other cultivars and for other regions are needed focusing on the on-site quantification of post-harvest losses.

Trichoderma brevicompactum sp. nov.

Trichoderma brevicompactum, a new species, was isolated from soil or tree bark in North, Central and South America, including the Caribbean Islands, and southwestern and southeastern Asia. Morphological and physiological characters, the internal transcribed spacer regions of the rDNA cluster (ITS1-5.8SrDNA-ITS2) and partial sequences of translation elongation factor 1-alpha (tef1) are described. Trichoderma brevicompactum is characterized by a pachybasium-type morphology, morphologically resembling other small-spored species referable to Trichoderma section Pachybasium but with essentially subglobose conidia. It is most closely related phylogenetically to Hypocrea lutea, from which it differs in morphological and physiological characters.

Plant root carbohydrates affect growth behaviour of endophytic microfungi.

Abstract Peucedanum alsaticum and Peucedanum cervaria represent characteristic umbellifers (Apiaceae) of calcareous grasslands in Central and Eastern Europe. Both accumulate glucose, fructose, mannitol and sucrose as dominant carbohydrates in their roots. The objective of the study was to determine if endophytes utilise host plant carbohydrates differently than rhizosphere and bulk soil microfungi. Inula ensifolia (Asteraceae), Lathyrus latifolius (Fabaceae) and Bromus erectus (Poaceae), all plants that grow along with the two umbellifers, accumulated only sucrose as major sugar in their roots. Germ tube growth of 30 microfungal isolates, recovered from various rhizosphere habitats, was quantified in microdilutions (10-5000 mug ml(-1)) of a number of substrates, including glucose, sucrose, mannitol and the water-soluble plant root carbohydrate mixtures. Multivariate analysis of variance and subsequent least significant difference analysis of isolate group means revealed that sucrose and mannitol utilisation affected affiliation to a certain fungal lifestyle. Endophytes utilised host plant carbohydrates more efficiently at lower concentrations. Conversely, higher concentrations slowed their growth. Non-host carbohydrates did not cause comparable effects. The results suggest that root carbohydrate diversity may determine fungal diversity in natural rhizosphere environments.

Determination of the carbon content of airborne fungal spores.

Airborne fungal spores contribute potentially to the organic carbon of the atmospheric aerosol, mainly in the "coarse aerosol" size range 2.5-10 microm aerodynamic equivalent diameter (aed). Here, we report about a procedure to determine the organic carbon content of fungal spores frequently observed in the atmosphere. Furthermore, we apply a new (carbon/individual) factor to quantify the amount of fungal-spores-derived organic carbon in aerosol collected at a mountain site in Austria. Spores of representatives of Cladosporium sp., Aspergillus sp., Penicillium sp., and Alternaria sp., the four predominant airborne genera, were analyzed for their carbon content using two different analytical procedures. The result was an average carbon content of 13 pg C/spore (RSD, 46%), or expressed as a carbon-per-volume ratio, 0.38 pg C/microm3 (RSD, 30%). These values are comparable to conversion factors for bacteria and some representatives of the zooplankton. Because biopolymers are suspected of interfering with elemental carbon determination by thermal methods, the amount of "fungal carbon" that might be erroneously mistaken for soot carbon was determined using the "two-step combustion" method of Cachier et al. and termed as "apparent elemental carbon" (AEC). This fraction amounted to up to 46% of the initial fungal carbon content. Although the aerosol samples were collected in March under wintry conditions, the organic carbon from fungal spores amounted to 2.9-5.4% of organic carbon in the "coarse mode" size fraction.