The changes of certain ripeness and quality parameters for plums (Prunus Domestica L.) during ripening

V Sadjarskem centru Maribor — Gačnik smo v letu 2010 preučevali razvoj nekaterih parametrov zrelosti in kakovosti sliv Prunus domestica L. V poskus so bile vključene tri sorte sliv: ´Valor´, ´Stanley´ in ´Hanita´. Namen poskusa je bil ugotoviti optimalni čas obiranja za posamezno sorto sliv ter določiti povezavo med trdoto mesa plodov, maso plodov ter vsebnostjo topne suhe snovi z barvo plodov. Rezultati poskusa so pokazali, da barva kot parameter kakovosti in hkrati zrelosti pri različnih sortah sliv ni dober pokazatelj optimalnega časa obiranja, saj se je pri sorti ´Valor´ razvila 17 dni pred užitno zrelostjo, pri sorti ´Stanley´ 10 dni in pri sorti ´Hanita´ 15 dni pred užitno zrelostjo. Pokazalo se je, da sorta ´Hanita´ v naših klimatskih pogojih doseže najintenzivnejšo modro barvo, največ topne suhe snovi (18,72 ºBrix) razvije sorta ´Valor´ in največjo trdoto mesa v času optimalne zrelosti (0,99 kg/cm²) obdrži sorta ´Stanley´.At the Fruit growing centre Maribor – Gačnik in 2010 we investigated the development of certain ripeness parameters for plums Prunus Domestica L. The experiment included three varieties of plums: ´Valor´, ´Stanley´ and ´Hanita´. The aim of the experiment was to determine the optimal harvest time for each variety of plums and the connection between fruit flesh firmness and its weight as well as between soluble dry matter and the colour of the fruit. The results showed that with different varieties of plums the colour as a quality and a ripeness parameter is not a good indicator of the optimal harvest time, as with ´Valor´ the colour developed 17 days, with ´Stanley´ 10 days and with ´Hanita´ 15 days before it was ripe enough to eat. It was established that in Slovenian climatic conditions in the optimal ripeness stage ´Hanita´ develops the most intense blue colour, ´Valor´ develops the maximum solid dry matter (18.72 °Brix) and ´Stanley´ keeps the firmest flesh (0.99 kg/cm2)