[Methodology for an assessment of derived radiation levels for agrocenoses].

Radiation protection of agrarian ecosystems should be considered as an integral part of a system for radiation protection of environment, with a special concern to agroecosystems' features. A methodology is proposed for an assessment of maximum permissible doses of radiation impact for agrocenoses based on an unified analysis of available data about effects of radiation in cultivated plants. It is considered as a component of radiation protection system for agricultural ecosystems.

[The dynamics of 137Cs content in ontogenesis in barley grown on soil with background and increased contents of heavy metals].

The uptake by barley and the distribution between the vegetative and the generative organs of 137Cs, K and Ca was studied when plants were grown on soddy-podzolic soil with the background content of heavy metals and soil polluted with Cd and Co at concentrations significantly above the maximum permissible concentration (50 i 100 mg/kg accordingly). The reduction was found in 137Cs accumulation and removal with barley in ontogenesis under the action of increased contents of heavy metals in the soil, which was caused by their phytotoxic effect.

[Leptinotarsa decemlineata Say sensitivity to ionizing radiation and pesticides].

The effects of acute gamma-irradiation on the Colorado potato beetle (Leptinotarsa decemlineata Say) and sensitivity of insects, long time exposed on radioactively contaminated territories, to pesticides were studied. LD50 values of insects to ionizing radiation during the ontogenesis process was shown to increase (from 8 to 48 Gy). Differences were noted in the development rates of the natural population of beetles collected on agricultural lands with 137Cs contamination density of 0.

[The influence of potassium humate on 137Cs accumulation by barley growing on soil with different fertility].

The changes studied in 137Cs uptake by plants and its distribution between vegetative and generative organs of barley cultivated with the application of potassium humate. A relationship has been found between 137Cs accumulation size in barley at various ontogenesis stages and way of potassium humate application (treatment of seeds or plants), as well as availability of mineral nutrients in the soil. Changes in K+ and NH4+ concentrations in soil solution are shown to be of prevailing importance in regulating 137Cs uptake by plants compared with potassium humate effects.