Plant size in winter wheat, a genetically-determined feature, is directly impacted by vegetation and technological factors such as fertiliser rate and particularly nitrogen fertiliser rates. Re-search carried out aimed at assessing the level of interdependence between fertilisation system and plant size in winter wheat as well as fall risks caused by the fertilisers. Fertilisation was done with nitrogen rates ranging between 0 and 200 kg of active substance per ha both alone and associated with phosphorus and potassium at rates between 0 and 150 kg of active substance per ha. In the stem, in the area of basal internodes, there is also accumulation of tension and, when the tissues have a poor mechanical resistance because of cell elongation, break risks increase in the stem. Another area of accumulation of tension in the stem is at soil level, in the roots, where there can also be mechanical actions of tissue damage. Plants responded to mineral fertilisers by different growth of the stem until kernel appearance and until maturity depending on the fertiliser rate and on the type of fertiliser applied. Plant size ranging between 74.6 cm in the control variant (not treated) and 88.90 cm in the variant treated with N150P150K150 in the year 2009 and 85.76 cm in the control variant (not treated) and 99.53 cm in the variant treated with N200P100K100 in the year 2010. Fall risk occurs in rates over 150 kg/ha of nitrogen when applied unilaterally and also under environ-mental conditions that enhance tensions generated in the stem and increase sensitivity to fall.

mineral fertilizers; fertilization system; winter wheat stem; cereal fall; correlations

Presentation: oral