Effect of Prohexadione-Ca and young canes removal on physiological characteristics of leaf and fruit in raspberry cultivar 'Willamette'

Abstract

The research was designed to evaluate the effect of growth regulator Prohexadione-Ca (ProCa) and young canes removal on the changes of photosynthetic pigment content and modification activities of antioxidant enzyme defense system in leaves and fruits of raspberry cultivar 'Willamette' (Rubus idaeus L.). The experiment was performed in the period of 2011-2012. It consisted of five treatments: control - no treatment; 2ProCa - with 2 ProCa applications; Z - one removal of young canes; Z+2ProCa - young canes removal with 2 ProCa applications; 2Z - two removals of young canes. The first series of young canes were removed for the first time in mid-April and for the second time at the begining of May. In 2ProCa and Z+2ProCa treatments foliar application of ProCa was carried out twice during the period of April-May in interval of three weeks, i.e. when the primocane growth reached 30 cm in height. The following concentrations of ProCa: 125 ppm (first application) and 200 ppm (second application) were applied. Significantly higher mean values of chlorophyll b content were registered in the 2ProCa (42.84 μg·g-1 FW) and Z+2ProCa (46.12 μg·g-1 FW) treatment. The highest SOD and POD activities were found in leaves of new young canes which developed after the young canes removal was applied. Z+2ProCa treatment significantly increased CAT activity in raspberry leaves (63.51 U mg-1 prot.). Both of implemented measures, especially applied in combination, resulted in higher activity of CAT, POD and SOD enzymes in the fruits of the examined cultivar.

U radu je proučavan uticaj retardanta rasta Prohexadione-Ca (ProCa) i pomotehničke mere zakidanja prvih serija mladih izdanaka na promene u sadržaju fotosintetskih pigmenata i modifikaciju aktivnosti enzima antioksidacionog zaštitnog sistema u listovima i plodovima sorte maline 'Willamette' (Rubus idaeus L.). Eksperiment izveden u periodu 2011-2012. godine obuhvatio je pet tretmana: kontrola - bez tretiranja; 2ProCa - sa dva tretiranja ProCa i bez zakidanja izdanaka; Z - sa jednim zakidanjem izdanaka i bez tretiranja ProCa; Z+2ProCa - sa jednim zakidanjem izdanaka i dva tretiranja ProCa; 2Z - sa dva zakidanja izdanaka i bez tretiranja ProCa. Prvo zakidanje mladih izdanaka je obavljeno sredinom aprila, a drugo krajem aprila u obe godine ispitivanja. U 2ProCa i Z+2ProCa tretmanu folijarna aplikacija sa ProCa vršena je dva puta u periodu april-maj u intervalu od tri nedelje srazmerno dinamici porasta novih izdanaka tj. u momentu kada oni dostignu visinu od 30 cm. Primenjene su sledeće koncentracije ProCa: 125 ppm (kod prvog tretiranja) i 200 ppm (kod drugog tretiranja). Statistički značajno veća prosečna vrednost sadržaja hlorofila b registrovana je u 2ProCa (42,84 μg·g-1 sveže mase lista) i Z+2ProCa (46,12 μg·g-1 sveže mase lista) tretmanima. Najveća aktivnost enzima superoksid dismutaze i peroksidaze registrovana je u listovima novih mladih izdanaka, koji su se razvili nakon primenjene mere zakidanja izdanaka. Z+2ProCa tretman je uticao na značajno povećanje aktivnosti katalaza u listovima maline (63,51 U mg-1 proteina). Obe navedene mere, a naročito primenjene u kombinaciji, uticale su na povećanje aktivnosti pomenutih enzima u plodu ispitivane sorte.