Influence of measuring angle,nitrogen fertilization,and variety on spectral reflectance of winter oilseed rape canopies

A field experiment with winter oilseed rape was conducted near Göttingen (northern Germany) in the growing season 1998–99. Twelve varieties were compared at two nitrogen (N) application rates (0, 206 kg N ha^–1) regarding shoot dry matter production, shoot N content, shoot N uptake (beginning of shooting, beginning of flowering), and seed yield. Canopy reflectance was measured one week before the beginning of shooting and one week before flowering at different wavelengths between 550 and 940 nm using a spectral reflectance sensor, type FAL II. The vegetation indices red edge inflection point (RIP), soil adjusted vegetation index (SAVI), and normalized vegetation index (NDVI) introduced in literature as indicators of growth parameters were calculated from the reflectance values and compared with growth parameters. The results showed that the measuring angle (–45° to 45°) had a significant influence on the calculated vegetation indices. Therefore, the measuring angle should be kept constant during the measurements. Nitrogen fertilization led to an increase of all vegetation indices. The results revealed significant differences between the tested varieties, indicating problems regarding an accurate estimation of the N status of the crop. Consistent differences in the vegetation indices appeared between varieties with extremely different growth parameters. However, no general relationship between growth parameters and vegetation indices of the 12 varieties could be found. Therefore, variety‐specific calibrations are necessary. The indices RIP and SAVI resulted in similar statements and seem to be good parameters regarding N effects and variety differences, whereas NDVI could resolve variety differences in the fertilized treatments only imperfectly.     

Inheritance of calyx shape in the genus Origanum (Lamiaceae)

Five different traits responsible for calyx shape within the genus Origanum were found to be determined by five independent genes. The five traits are bell‐shaped vs. tubular‐shaped calyx, angular vs. round teeth on the upper lip, entire vs. denticulate upper lip, fully developed vs. reduced lower lip and entire vs. denticulate lower lip. The simple Mendelian inheritance of most traits for calyx shape could be used to identify hybrids between Origanum species arising from open‐pollinated plants and so avoid tedious artificial pollination resulting from small flower sizes in Origanum. Such hybrids are interesting base material for character transfer (e.g. winter hardiness or seed size) between economically important species.     

Analyzing time and fuel consumption in road transport of round wood with an onboard fleet manager

Round wood supply in Austria is often affected by different factors such as bottlenecks or oversupply due to changing market, weather and road conditions. An additional factor impacting the complex wood supply chain is the rising transport costs from the landing to the sawmill. Logging trucks are the primary transportation technology used from the forest to the customer??s site. The objectives of this study were to analyze the actual situation and characteristics of typical trucking activities for round wood supply from the region to an Austrian sawmill. The study used time and fuel consumption, proportion of travel on forest roads and average speed on different functional road classes to estimate productivity and costs. Data collection including GPS-tracking was done using fleet management equipment built into the driver??s cabin. The GPS-routes were analyzed in ArcGIS 9.3 based on the national road network and its attributes. The sawmill studied with a yearly demand of 600,000 m³ round wood was located in southern Austria. In total, more than 2,000 round trips operated by seven logging trucks recorded close to 100,000 km. The transport distance from the forest to the sawmill averaged 51 km. The average share on forest roads within a route to the sawmill was 14.2% with an average speed of 13.5 km/h, whereby the forest road is defined as road with minor importance. Transport costs from the forest site to the sawmill with a truck and trailer were ? 11/m³ solid timber based on an average load size of 25 m³. An average 0.77 l of diesel fuel per kilometer was consumed during a round trip including all work phases. A trip to an interim storage location consumed 2.05 l/km due to the number of work phases without driving distance.     

Harznutzung in Deutschland

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