Summary:

The study of drip fertigation of winter squash ‘Gomez' was conducted on the very light soil on the experimental field in Kruszyn Krajeński near Bydgoszcz in the years 2007 and 2008. The research was established as one-factorial, using the method of drawn blocks, in four replications. Drip fertigation (DF) as the liquid fertilization supplied nitrogen, potassium and phosphorus to the plants three times during growing season. As the control (DP), the drip irrigation combined with broadcast application was used. The potassium and phosphorus fertilization of control plots was applied before seed sawing. The nitrogen fertilization of control plots was provided in three single doses during vegetation. The liquid and powder fertilizations were performed at the same time. The complex fertilizer 'Universol Blue' (N:P:K = 18:11:18) was used. The dose of fertilizer was 3:2:3 (187.5:125:187.5 kg of NPK per ha). The irrigation was conducted using the drip line 'T-Tape'. The liquid fertilizer was mixed by the 'Dosatron' dispenser. The irrigation started when the soil water pressure, measured with the tensiometers, was near -0.04 MPa. In comparison to the control (powder fertilization), the drip fertigation (liquid fertilization) significantly increased marketable fruit yield, single fruit weight and fruit number. Most of the tested chemical components of ‘Gomez' fruits (vitamin C, total sugar, monosaccharides, saccharose, total carotenoids and ß-carotin) were not significantly influenced by drip fertigation. However, the level of dry weight of winter squash ‘Gomez' fruits was reduced by drip fertigation.