Summary:

The aim of the study was to determine the influence of drip irrigation on yields of winter squash cv.‘Rouge vif d'Etampes' grown on the very light soil in the region of decreased rainfall amounts in the vegetation period. The field experiment was conducted in 2007-2008 at Kruszyn Krajeński near Bydgoszcz on the soil of quality class V-VI (very weak and weak-rye-soil-complexes). Field water capacity in the soil layer 0-50 cm was 57,5 mm, while the effective useful retention amounted 29,3 mm. The experiment was designed and carried out as one-factorial trial in four replications. The single plot area was 11,2 m2. Irrigation was used in the two variants: W0 - without irrigation (control) and W1 -drip irrigation. Drip ir-rigation was conducted according to soil tensiometer indications (-0,04 MPa). Drip irrigation significantly increased marketable yields of winter squash ‘Rouge vif d'Etampes' from 34,2 t.ha-1 to 75 t.ha-1 (increase by 40,8 t ha-1, i.e. 119 %). This yield increase was obtained thanks to significant increases the weight of a fruit and its size (horizontal and vertical diameter) as well as the num-ber of fruits.