EN
Development of genetically modified crop cultivars by the private biotechnology companies and their wide acceptance by farmers in a number of countries did not follow proper evaluation of their unintended effects on environment by the public research institutions in the past. The paper presents results of the first properly organized multi-instututional and multi-disciplinary field studies carried out in the United Kongdom on the effect of herbicide-tolerant transgenic cultivars of beet, maize and spring oilseed rape on selected components of agrocenosis. The methodology and techniques used in these wide scale studies undertaken under commercial fann conditions in various regions may serve as a model for other reseach programmes and countries. The needs for support by the national research institutions and foundations for such field studies in other countries are obvious in the face of emotional reactions of various groups of society, including some scientists, on releasing of genetically modified cultivars with novel properties. The author having 35 years of experience in breeding the crop plant resistance to pests hopes that pro and contra arguments for GMO will only be supported by objective research data.