Die Rentabilit?t der Forstwirtschaft

Ohne Zusammenfassung     

Accessibility, reactivity and supramolecular structure of E. globulus pulps with reduced xylan content

The correlation of structural assembly on a molecular level with macroscale properties such as accessibility and reactivity was investigated. A series of TCF-bleached E. globulus kraft dissolving pulps was prepared aiming at a specification suitable for viscose application. The removal of xylan to a comparable level was achieved by different pre- and post-treatments. Solid-state CP-MAS ¹³C NMR was used to determine the degree of order and the lateral fibril dimensions of cellulose fibrils. The results of the NMR measurements were related to the processability of these pulps during viscose manufacture, expressed in terms of filterability of the viscose dope and its amount of undissolved particles. The cellulose crystallinity did not affect the pulp reactivity. It was noticed that the cold caustic extracted (CCE) pulps revealed both large fibril aggregate width as determined from NMR data and low reactivity toward xanthation at the same time. These pulps exhibited significantly higher amounts of alkali-resistant xylan than those prepared by prehydrolysis kraft cooking.     

Field‐related quality management system for grass silage production

A model for the prediction of the silage quality was tested in several large farms in northeast Germany. The model uses data and information on the fresh grass and the application of silage additives at ensiling to evaluate the “ensilability.” During clamp filling, the model analyses information on the filling performance, activity of compacting machines and hermitic covering of the clamp and evaluates the “ensiling technique.” Both “ensilability” and “ensiling technique” are assessed as “good,” “medium” or “bad” and pooled in “silage evaluation grades” 1–5. In the present model version, the predicted silage net energy lactation (NEL) and crude protein (CP) content is between 3% (for the best grade 1) and 15% (for the weakest grade 5) lower than the fresh grass NEL and CP content. In our experiments, all the grass silage production systems were characterized by “good” “ensilability” and “ensiling technique.” Under those circumstances, the experimental results indicated a closer numerical relation between fresh grass and measured silage NEL and CP content than between predicted silage and measured silage NEL and CP content. The results reveal that the model prediction calculation should be changed compared to the present version. If “ensilability” and “ensiling technique” are evaluated as “good,” the predicted silage NEL and CP content should be forecasted in a range between 0% and 3% decrease compared to fresh grass.     

Duckweed for Human Nutrition: No Cytotoxic and No Anti-Proliferative Effects on Human Cell Lines

Plant Foods for Human Nutrition - Duckweeds (Lemnaceae) possess good qualitative and quantitative profiles of nutritional components for its use as human food. However, no studies have been...     

Detection of a related difference in efficacy of azadirachtin treatments for the control of whiteflies on Gerbera jamesonii by testing for interactions in generalised linear models

BACKGROUND: Within a project cluster, systemical effects of two neem treatments (Neem Azal? U and Neem Pellet) on the number of Trialeurodes vaporariorum (Westw.) in Gerbera jamesonii Flori Line Maxi were investigated. In order to minimise adverse ecological effects of a product, a new plant protection product can be declared as superior to a reference if it shows the same or a higher effect at a lower dosage. RESULTS: Based on a negative binomial model, the efficacy of the two treatments is compared by applying a user‐defined interaction contrast in a multiple‐contrast test framework. The corresponding calculation of simultaneous confidence intervals for the ratio of model parameters provides conclusions about statistical significance and biological relevance. The validity of the approach is shown by a small simulation study. As a result of the experiment, besides a significant difference between two negative control treatments, no significant difference between the efficiency of the two neem treatments (Neem Azal? U and Neem Pellet) could be detected. CONCLUSIONS: Simultaneous confidence intervals for linear combinations of parameters of generalised linear models provide a useful way to compare the efficiency of two plant protection products. The results for the azadirachtin experiment indicate that large differences between any application effects of either Neem Azal? U or Neem Pellet cannot be expected. Copyright © 2009 Society of Chemical Industry     

Criteria and standards for sustainable agriculture

This paper presents an assessment system which on the basis of quantifiable criteria and appropriate orientation values describes the risk potentials of farming as far as environmental protection and sustainability is concerned. The procedure addresses the most significant risks and suggests ranges for their tolerability. By this way farmers can recognize principal shortcomings of their management and look for appropriate countermeasures to cope with them. The guiding principle is a way of farming which uses the available resources and the production potential as efficiently as possible, while keeping the unfavorable impacts on soils, water, air and biota within acceptable limits. Several years of investigations in about 125 different farms have shown that non‐tolerable impacts of farming on the environment are predominantly due to avoidable managerial mistakes. The suggested assessment system provides criteria for the actual magnitude and the tolerability of the different risk potentials and may thus help to substantiate the compliance with such general principles as ”︁good farming practice”.     

Adsorption von Pflanzenschutzmitteln und DOC an Saugkerzen aus Glas und Keramik

Sorption of pesticides and DOC on glass and ceramic suction cups Suction cups are widely used for the sampling of soil solution. Due to sorption and desorption processes the concentration of dissolved substances in the samples may vary considerably depending on the material of the suction cups. In order to minimize these losses, a new glass suction cup was developed. In laboratory studies, aqueous solutions of pesticides and DOC were percolated through both types of suction cups; the concentration of pesticides and DOC in the percolates was examined. The pesticides pendimethaline, terbuthylazine, metolachlor and chlortoluron were tested at concentrations of 2, 20, and 200 μg 1⁻¹. The average losses due to sorption by the suction cups were 10% (1.1—31%) for the ceramic cups and 3.1% (0—11%) for the glass cups. Sorption effects increased with increasing hydrophobicity of the pesticides and decreasing pesticide concentrations. Thus, at a concentration of 2 μg 1⁻¹ ceramic cups sorbed 31% of pendimethaline compared with 7.7% in the case of glass cups. Corresponding tests with soilborne DOC solutions yielded comparable results. Ceramic suction cups adsorbed up to 50% of the DOC input concentration, while glass cups retarded 2.4% on average. These results are especially noteworthy because soilborne dissolved organic substances are effective sorbents and carriers for pesticides. The new type of glass suction cups may help to improve the results of pesticide field studies and, in consequence, the assessment and prediction of the leaching behavior of pesticides.     

New fluoro intermediates for herbicidal sulfonylureas

New pyrimidine and triazine intermediates for herbicidal sulfonylureas are prepared as follows: 2,4-dichloro-6-methylpyrimidine is converted via a halogenation, halogen exchange and substitution sequence to 2-amino-4-trifluoromethyl-6-trifluoromethoxypyrimidine. New fluoromethyl-triazines are available starting from guanidine, trichloroacetonitrile and difluoroacetic anhydride, or alternatively from thiocarbamoyl guanidine and chlorodifluoroacetic ester ring closure. To obtain new o-fluoroalkyl-benzenesulfonamide precursors, o-chlorobenzaldehyde was fluorinated with sulfur tetrafluoride, or a bromobenzene derivative was subjected to a substitution reaction with sodium pentafluoropropionate. Sulfonylureas derived from trifluoromethylpyrimidines with an m-methylthio substituent are selective post-emergence herbicides in cotton, presumably due to sulfone metabolization. Selectivity in wheat is obtained by combining 4-methoxy-6-trifluoromethylpyrimidine with a lipophilic difluoromethyl-benzenesulfonamide moiety. Also in the difluoromethyl-triazine series, the combination with the difluoromethyl-benzenesulfonamide moiety is a good choice for wheat selectivity. Chlorodifluoromethyl- and trifluoromethyltriazines, however, combine better with an aromatic ester for best activity and selectivity in wheat. Selected compounds are undergoing broad field tests in wheat.     

(2E,4Z )-Decadienoic acid and (2E,4Z,7Z )-decatrienoic acid,two herbicidal metabolites from Streptomyces viridochromogenes Tü 6105

Two fatty acids, (2E,4Z)-decadienoic acid and (2E,4Z,7Z)-decatrienoic acid, the latter being described for the first time as a natural product, were detected in the culture filtrate of Streptomyces viridochromogenes Tü 6105 by HPLC-diode array screening, purified by chromatographic methods and structurally elucidated by NMR techniques. Both metabolites show strong herbicidal activity against Lemna minor and Lepidium sativum. The herbicidal activities of the isolated compounds were compared with those of similar fatty acids and derivatives. © 1999 Society of Chemical Industry     

DHPLC scoring of a SNP between promoter sequences of HMW glutenin x-type alleles at the Glu-D1 locus in wheat

The promoter regions of HMW glutenin x-type genes at the Glu-D1 locus were surveyed for SNPs within a subpopulation of German bread wheat cultivars. On the basis of the promoter sequences of HMW glutenin subunit genes Glu-A1-x1, Glu-A1-x2, Glu-B1-x1, Glu-B1-x7, Glu-D1-x2, and Glu-D1-x5, an amplification refractory mutation system assay was designed to selectively amplify Dx-specific PCR fragments. Comparative sequence analysis among seven Glu-D1-x2 and seven Glu-D1-x5 wheat cultivars only confirmed a G-A transition in the promoter sequence to be a true polymorphism. SNP scoring by DHPLC of 95 German bread wheat cultivars, with the exception of cv. Anemos, showed that the transition completely agreed with the presence of HMW glutenin subunits 1Dx5 + 1Dy10 in SDS-PAGE. Therefore, the developed DHPLC assay is suitable for high-throughput genotyping to assist the selection of HMW glutenin genes in wheat quality breeding programs.