Dislodgeable residues and persistence of diazinon,chlorpyrifos and isofenphos following their application to turfgrass

In laboratory experiments, residues of diazinon applied to turfgrass, Poa pratensis L., that could be dislodged by rubbing with cheese-cloth, declined from c. 10% of the total applied when the grass was vigorously rubbed immediately after application to 0.3% after 1 day. Sunlight did not influence the rate of decline in dislodgeable residues or residues remaining on or within the leaf blades. In field experiments where 4.5 kg ha^?1 of diazinon was applied in liquid or granular form, about 20 times more diazinon was dislodged from the liquid formulation immediately after application than from the granular. By 1 day after application the percentage of the total applied diazinon that could be dislodged was equal for both formulations. Rainfall had a significant effect on the amount dislodged from grass blades, but mowing did not. Similar rates of decline in the dislodgeable fraction of diazinon, chlorpyrifos and isofenphos were observed in field experiments. Recovery of the dislodgeable fraction declined to 0.25% or less of the total amount of any of these insecticides by 1 day after application. However, residues in the thatch remained sufficiently high for control of insects for up to 7 days after application for diazinon and 14 days for chlorpyrifos and isofenphos.     

Influence of thermal and mechanical treatment of animal feed on the true digestibility of amino acids. 1. True digestibility of amino acids in soy bean meals treated by varying heat]

Thermal treatment inactivates harmful components in some feedingstuffs such as extracted soy bean meal. The true digestibility of amino acids from untreated and heat-treated extracted soya bean meal had been determined in order to investigate the great variety of ways in which thermal treatment might affect food proteins, e.g. in producing a decomposition of inhibitors or damaging the amino acids. The trials were carried out with young pigs.     

Fenbendazole. I. Structure-activity relationships

Substitution of alkyl benzimidazol-2-ylcarbamates by phenoxy- or phenylthio-groups in the 5-position results in an increase in anthelmintic activity. The biological spectrum is altered by substitution of the phenyl ring. A sulphonic ester substituent in the 5-position of the benzimidazole nucleus also increases anthelmintic activity.     

Neospora caninum: Serological follow-up in dairy cows during pregnancy

We conducted a longitudinal study to follow-up the anti-Neospora caninum serologic status in 30 initially seropositive and 83 initially seronegative cows during their pregnancy. Study cows were blood-sampled every other month during pregnancy until parturition. Blood serum samples were screened for anti-N. caninum antibodies by ELISA. Cows that seroconverted were re-tested by immunoblot as a confirmation test. Among 30 seropositive cows, 28 cows remained seropositive during the whole pregnancy, whereas 2 cows transiently tested negative at least once during pregnancy. Among 83 seronegative cows, 82 cows remained seronegative and 1 cow tested positive three times during the sixth, eighth and last month of pregnancy. As only 2 out of 30 seropositive animals and 1 out of 83 animals changed their serologic status during pregnancy, the study results indicate that there is only a minor temporal instability of anti-N. caninum antibody reactivity in adult cattle.     

Effects of Forest Management on Nitrate Concentrations in Seepage Water of Forests in Southern Bavaria,Germany

We performed seepage water studies in three forested study areas in Southern Bavaria, Germany in order to identify forest management effects on nitrate concentrations. In total 95 stands representing different age classes (up to 100 years), tree species (mainly spruce and beech) and regeneration methods (from clearcut to single tree selection) were included. In the period between 1998 and 2000, water samples were taken from below the rooting zone with tension lysimeters and nitrate concentration was determined. Average nitrate concentrations were calculated for each stratum (stand age, tree species, regeneration method). These data were combined with forest inventory data in order to predict regional nitrate leaching. Nitrate concentrations were generally higher in mature spruce stands than in mature beech stands. In spruce stands, we observed a clear age-related pattern, with negligible nitrate concentrations in stands younger than 40 years and higher concentrations in older stands. In beech stands nitrate concentrations were low and independent of age. In clearcut areas nitrate concentrations were significantly higher than in areas treated with small-scale regeneration methods. Forest management effects were highest in the study area with the highest N-input and lowest in the study area with the lowest N-input and highest N-retention capacity. In general changes of forest management have mainly long-term effects. The reduction of nitrogen deposition remains a crucial factor in avoiding increased nitrate leaching into forest groundwater resources.