Summary:

The weather conditions in winter 2011/2012 in Poland caused severe frost killing of winter crops (in most areas up to 90%) requiring spring resowing. This brought about a considerable impact of chemical plant protection. The paper presents results from two farms, belonging to a State Treasury company, with intensive agricultural production, located in the Wielkopolska voivodship. The number of plant protection treatments increased due to resowing from 39.9 to 81.4%, depending on the farm, and the amount of used p.p.p.(plant protection products) increased from 51.9 to 153.7%. Costs of used p.p.p. increased overall by 28.5%. The value of multi-criteria index of pesticides negative impact on the environment increased from 18.8 to 39.8% in farms 1 and 2. Identifying extremes in plant protection will allow more accurate than only on the basis of average values, planning and calculation of effect in production, as well as projections of adaptation processes to the changing conditions of production caused by the on-going global climatic changes.