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The effects of irradiances of 920 and 1200 mW m(-2) (biologically effective weighted irradiance) were examined in 2 Metarhizium album strains, 26 M. anisopliae strains, 1 M. flavoviride strain, and 1 M. taii strain isolated from sites located at latitudes from 61 degrees N to 54 degrees S. Conidia were exposed to UV-B from 1 to 6 h and subsequently examined(More)
The potential effects of increased ultraviolet-B radiation (UV-B, 280–320 nm) simulating stratospheric ozone depletion in field studies with vascular plants have previously been summarized only in narrative literature reviews. In this quantitative synthesis, we have assessed the significance of solar UV-B enhancement for ten commonly measured variables(More)
Based on research to date, we can state some expectations about terrestrial ecosystem response as several elements of global climate change develop in coming decades. Higher plant species will vary considerably in their response to elevated UV-B radiation, but the most common general effects are reductions in height of plants, decreased shoot mass if ozone(More)
The entomopathogenic hyphomycete Metarhizium anisopliae has been used in programs of agricultural pest and disease vector control in several countries. Exposure to simulated solar radiation for a few hours can completely inactivate the conidia of the fungus. In the present study we determined the effect of exposures to full-spectrum sunlight and to solar(More)
Field experiments assessing UV-B effects on plants have been conducted using two contrasting techniques: supplementation of solar UV-B with radiation from fluorescent UV lamps and the exclusion of solar UV-B with filters. We compared these two approaches by growing lettuce and oat simultaneously under three conditions: UV-B exclusion, near-ambient UV-B(More)
A multispecies canopy photosynthesis simulation model was used to examine the importance of canopy structure in influencing light interception and carbon gain in mixed and pure stands of wheat (Triticum aestivum L.) and wild oat (Avena fatua L.), a common weedy competitor of wheat. In the mixtures, the fraction of the simulated canopy photosynthesis(More)
Solar ultraviolet radiation (UV-A and UV-B) is a major factor in failure of programs using the insect pathogenic fungus Metarhizium anisopliae as a biological control agent. Studies were conducted to determine if growth conditions, viz. artificial (agar media or rice grain) or natural (infected insects) substrates for conidial production affect two traits(More)
We tested the effects of irradiances of 920 and 1200 mW m-2 (weighted irradiance) on the conidia and germinants of the entomopathogenic Hyphomycete Metarhizium anisopliae. The conidia were exposed to the two irradiances for 1, 2, 4, 6, 7 or 8 h. Increased exposure decreased relative percent culturability. The inactivation provoked by the irradiance of 1200(More)
We evaluated the effects of exposure to doses supplied at an environmentally realistic intensity of UV-B radiation (800 mW m(-2) weighted irradiance) on the culturability and germination of selected strains of the entomopathogenic Hyphomycetes Verticillium lecanii and Aphanocladium album. Increased UV-B exposure decreased relative percent culturability for(More)
In several phases of assessing implications of stratospheric ozone reduction for plants, biological spectral weighting functions (BSWF) play a key role: calculating the increase of biologically effective solar ultraviolet-B radiation (UV-BBE) due to ozone reduction, assessing current latitudinal gradients of UV-BBE, and comparing solar UV-BBE with that from(More)