SUMMARY
The experiments were carried out to find out the effect of Australian tea tree (Melaleuca alternifolia Ch.) oil on the quality of organic carrot (Daucus carota L.) ‘Perfekcja TOR’ seeds. The cultivar is late, high yielding, good for storage and useful for processing. Its flesh is juicy and very tasty. The organic seeds for experiments were taken from a Polish seed company “Torseed S.A.”. The seeds were soaked for 15 minutes in 0,25 – 0,75% water and alcohol solutions of 2% and 5% extract of the oil. In other treatment, only alcohol in the same concentrations and only chemical dressing compound – Dithane 45 80 WP - were used. The check seeds were untreated. It was found out that the Australian tea tree oil could be used to improve quality of organic carrot seeds. When soaked in 0,75% alcohol solution of 5% oil and then rinsed with water for 30 seconds, the seed germination increased from 56% to 72%. However, at the same time, a big variability in the received results was found, so the results were only partly proved statistically. The improvement of the germination came mostly from lowering the number of dead seeds in the sample. The tested oil did not affect the seed vigour. The used chemical Dithane increased the number of contaminated and healthy ungerminated germs, at the same time, however, decreased the number of dead seeds.