Walter Kühbauch

Learn More
Relative elemental growth rates (REGR) and lengths of epidermal cells along the elongation zone of Lolium perenne L. leaves were determined at four developmental stages ranging from shortly after emergence of the leaf tip to shortly before cessation of leaf growth. Plants were grown at constant light and temperature. At all developmental stages the length(More)
In order to evaluate economic and ecological benefits, site-specific weed control was realised in a 4-year experiment on five fields with a GPS-guided sprayer. An average of 54% of the herbicides could be saved. Savings were strongly dependent on crop and year. For grass weed herbicides, the savings were 90% in winter cereals, 78% in maize, and 36% in sugar(More)
Digital image processing has the potential to support the identification of plant species required for site-specific weed control in grassland swards. The present study focuses on the identification of one of the most invasive and persistent weed species on European grassland, the broad-leaved dock (Rumex obtusifolius L., R.o.), in complex mixtures of(More)
One of the most important tasks in precision farming is the site-specific application of fertilisers and pesticides in heterogeneous large-area fields. For such site-specific crop management, effective remote sensing methods for the detection of crop diseases and nutrient deficiencies are required. The aim of the present work was to compare laser-induced(More)
A four-year study of site-specific weed control is presented in this paper. Weed seedling distribution was sampled and mapped prior to and after post-emergence herbicide application in four fields planted with maize, sugar beets, winter wheat and winter barley, rotating on one site. Herbicides and other weed control strategies were applied site-specifically(More)
Tracing back the N use efficiency of long-term fertilizer trials is important for future management recommendations. Here we tested the changes in natural N-isotope composition as an indicator for N- management within a long-term fertilization lysimeter experiment in a low mountain range pasture ecosystem at Rengen (Eifel Mountains), Germany. Cattle slurry(More)
In Gebhardt et al. (2006) an object-oriented image classification algorithm was introduced for detecting Rumex obtusifolius (RUMOB) and other weeds in mixed grassland swards, based on shape, colour and texture features. This paper describes a new algorithm that improves classification accuracy. The leaves of the typical grassland weeds (RUMOB, Taraxacum(More)
Spring barley cv. Blenheim was grown from anthesis to harvest-ripeness in a controlled environment room at a constant temperature of 13~ in a 16h day. Ears were harvested at intervals, and grains from mid-ear were sampled (1) to establish the pattern of dry weight accumulation, and (2) to examine starch granule formation using scanning electron microscopy(More)
Auf einer Maisfläche wurde ein Herbizid aus der Gruppe der Sulfonylharnstoffe gegen Ungräser teilflächenspezifisch appliziert. Vier Wochen später wurde diese Maisfläche mit dem QuickBird-Satelliten aufgenommen. Es zeigten sich deutliche Unterschiede zwischen den behandelten und nicht behandelten Teilschlägen. Die NDVI-Werte, welche die Vitalität eines(More)