Summary:

The aim of the study was to determine the effect of drip irrigation on yielding of summer squash ‘White Bush' grown under conditions of two localities: Lipnik near Stargard Szczeciński (soil of quality class IVb, and of good-rye-soil-complex) and Kruszyn Krajeński near Bydgoszcz (soil of quality class V, and of weak-rye-soil-complex). The study was designed as one-factorial trial: drip irrigation as the experimental factor was considered. Drip irrigation was conducted according to soil tensiometer indications (-0.04 MPa). Both, in Lipnik as well as in Kruszyn Krajeński, drip irrigation significantly increased marketable yield of summer squash ‘White Bush'. A higher rise in yields due to irrigation was obtained in Kruszyn Krajeński than in Lipnik. Mean marketable yield of summer squash fruits in Lipnik was higher than that obtained in Kruszyn Krajeński. Drip irrigation significantly increased the single fruit weight in relation to the control, in both crop localities. The system of drip irrigation significantly affected the number of fruits per plant. Summer squash plants grown in Lipnik produced higher number of fruits, than in Kruszyn Krajeński. In addition, essential influence of drip irrigation was affirmed on chemical composition of fruits, i.e. dry matter, vitamin C, monosaccharides, saccharose, content of total sugars and sum of carotenoids and ß-carotin.