The methanol extract of the fruit pulp of Bromelia pinguin was evaluated for its antifungal activity. The extract showed a significant activity against some Trichophyton strains, although Candida strains were generally insensitive. 相似文献
The diatomaceous earth (DE) Dryacide® was tested under laboratory conditions on surfaces (2 g DE/m2) and in wheat grain (3 kg DE/t wheat) at a relative humidity of 70±5% and a temperature of 22±1°C. The wheat had a moisture content of 14.5%. The effect of surface treatments was tested onEphestia kuehniella, Oryzaephilus surinamensis, Tenebrio molitor andTribolium castaneum. The efficacy of grain treatments was determined usingEphestia elutella, O. surinamensis, Sitophilus granarius andTribolium confusum. In both treatments adult and larval stages were included.100% mortality were reached with the surface treatments in adults and larvae ofO. surinamensis and the adults ofT. molitor andE. kuehniella after an exposition time of 3–9 days. AgainstT. castaneum and the larvae ofT. molitor andE. kuehniella no complete control could be achieved.In the grain treatments the dosage of 3 kg DE/t wheat reached 100% mortality in all tested pests exceptS. granarius. Most sensitive wereO. surinamensis andE. elutella. InT. confusum the adults died within 13 days of treatment, but for complete control of the larvae 13 weeks were necessary. AgainstS. granarius the silica dust showed no satisfactory efficacy, because 49 days after beginning of the examinations beetles of the progeny hatched. Dryacide® could not prevent the reproduction of the granary weevil, but there was a lower number of progeny compared to the untreated control. 相似文献
20 trials of materials used in buildings have been offered to dermestid larvae to bore in for pupations. Two different types of damage are described. Eight different test substances have been more or less damaged by the larvae. 相似文献
Silvopastoral systems integrate the complexity of forestry and forage-livestock management in an economically and ecologically sustainable way. However, these systems have undergone intensive pressure over the past decades caused by changes in land uses, as well as, in local socioeconomic priorities that suppressed traditional practices such as livestock grazing. These changes have caused land cover spatiotemporal diversifications whose effects were investigated in a traditional oak silvopastoral system at western Greece. In order to investigate the effect of human activities over the study area, the spatiotemporal land cover changes in conjunction with human and animal population changes and the environmental factors altitude, soil depth, inclination and rock type were analyzed. Also, forest-crown density changes were examined as a complimentary factor for the investigation of human intervention in the study area. Data about land-cover changes were derived from aerial orthorectified photographs of years 1945 and 2008, complimented by maps of environmental factors. Data digitization was implemented by the use of ArcGis. Based on the data analysis it derives that land cover changes are mainly attributed to direct human intervention. Environmental factors affect the ecosystem in two ways; first by affecting the location, type and intensity of human activities in the area, for example, soil depth determines where land is more productive and so predetermines the location, type and intensity of agricultural activities. Secondly, in the areas without or with minimal human intervention, environmental factors affect directly the land cover in conjunction with natural species necessities and their antagonistic capabilities.
Research was conducted in northern Colorado in 2011 to estimate the crop water stress index (CWSI) and actual transpiration (Ta) of maize under a range of irrigation regimes. The main goal was to obtain these parameters with minimum instrumentation and measurements. The results confirmed that empirical baselines required for CWSI calculation are transferable within regions with similar climatic conditions, eliminating the need to develop them for each irrigation scheme. This means that maize CWSI can be determined using only two instruments: an infrared thermometer and an air temperature/relative humidity sensor. Reference evapotranspiration data obtained from a modified atmometer were similar to those estimated at a standard weather station, suggesting that maize Ta can be calculated based on CWSI and by adding one additional instrument: a modified atmometer. Estimated CWSI during four hourly periods centered on solar noon was largest during the 2 h after solar noon. Hence, this time window is recommended for once-a-day data acquisition if the goal is to capture maximum stress level. Maize Ta based on CWSI during the first hourly period (10:00–11:00) was closest to Ta estimates from a widely used crop coefficient model. Thus, this time window is recommended if the goal is to monitor maize water use. Average CWSI over the 2 h after solar noon and during the study period (early August to late September, 2011) was 0.19, 0.57, and 0.20 for plots under full, low-frequency deficit, and high-frequency deficit irrigation regimes, respectively. During the same period (50 days), total maize Ta based on the 10:00–11:00 CWSI was 218, 141, and 208 mm for the same treatments, respectively. These values were within 3 % of the results of the crop coefficient approach. 相似文献
Furrows are widely used in rainfed areas of semi-arid India for soil and water conservation. The orientation of furrows, either down or across slope, and their spacing influence the effectiveness of furrows as soil and water conservation measures. We evaluated treatments with furrows aligned down and across 3% sloping land at spacings of 90, 60 and 30 cm under simulated rainfall intensities of 80 and 100 mm/h on a shallow Alfisol. A bare plot without any furrows was considered as a control. A large (24 m × 3 m) rainfall simulator developed at the Central Research Institute for Dryland Agriculture (CRIDA), Hyderabad, was used for this controlled study. Run-off was measured by a calibrated tipping bucket run-off recorder. The effects of the treatments on peak flow rate (L/s), sediment loss with run-off water (kg/ha/mm), peak sediment concentration (g/L), run-off (per cent rainfall) and time to peak (min) were investigated. When compared with the control (no furrows), across slope furrowing with 60- and 30-cm spacing reduced sediment yields by 19.9 and 21.3 kg/ha/mm of run-off, respectively, under a rainfall intensity of 80 mm/h and 24 and 25.3 kg/ha/mm of run-off, respectively, under a rainfall intensity of 100 mm/h. For the control, sediment loss was 50.72 kg/ha/mm run-off and 56.68 kg/ha/mm run-off for rainfall intensities of 80 and 100 mm/h, respectively. Similar trends were recorded from observations of peak flow, time to peak and peak sediment concentration. Run-off hydrographs demonstrated the conservation value of across slope furrowing by delaying run-off initiation, reducing run-off and slowly releasing the run-off after the cessation of rainfall. The results show that furrow orientation has major effects on reducing run-off, whereas furrow spacing has insignificant effects. 相似文献
N2O Emissions from True Meadows Dependent on Location and N Fertilization Agricultural production is thought to be a main anthropogenic emitter of nitrous oxide (N2O), which contributes to global warming and the destruction of the ozone layer. There is still considerable uncertainty about the amount of N2O emission, and the site‐specific parameters that affect N2O emission. From October 1995 until March 1998 experiments were conducted at established field plots (true meadows) at three different sites, i.e. low mountain range (Eifel), lowland (Niederrhein), and moist meadows (Münsterland). Plots were fertilized with calcium ammonium nitrate (CAN) at nitrogen equivalents ranging from 0 to 360 kg N ha–1. N2O fluxes were measured throughout the whole year using the closed‐chamber method. In addition, data on temperature, water‐filled pore space and precipitation were collected. N2O emission rates (mg N2O‐N ha–1 h–1) were highest either after fertilizer application or in winter during frost, depending on the experimental site and N dosage. The annual amount of N losses due to N2O emission was dependent on the experimental site and the type and dosage of fertilizer. Disregarding the 360 kg N ha–1 level of the CAN treatments, the N losses in this experiment were less than 1.5 kg N2O‐N ha–1 yr–1. At low fertilizer dosage there was no reliable correlation between the amount of N that was applied and the amount of N2O that was emitted. However, with high fertilizer levels the N2O emissions increased gradually. Finally, N2O emissions were more influenced by the amount of CAN than by the site. 相似文献