EFFECT OF PROHEXADIONE-Ca AND YOUNG CANES REMOVAL ON PHYSIOLOGICAL CHARACTERISTICS OF LEAF AND FRUIT IN RASPBERRY CULTIVAR ‘WILLAMETTE’

The research was designed to evaluate the effect of growth regulatorprohexadione-ca (proca) and young canes removal on the changes ofphotosynthetic pigment content and modification activities of antioxidant enzymedefense system in leaves and fruits of raspberry cultivar ‘willamette’ (rubusidaeus l.). the experiment was performed in the period of 2011–2012. it consistedof five treatments: control – no treatment; 2proca – with 2 proca applications; z –one removal of young canes; z+2proca – young canes removal with 2 procaapplications; 2z – two removals of young canes. the first series of young caneswere removed for the first time in mid-april and for the second time at thebegining of may. in 2proca and z+2proca treatments foliar application of procawas 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 followingconcentrations of proca: 125 ppm (first application) and 200 ppm (secondapplication) were applied. significantly higher mean values of chlorophyll bcontent were registered in the 2proca (42.84 ?g·g-1 fw) and z+2proca (46.12?g·g-1 fw) treatment. the highest sod and pod activities were found in leaves ofnew 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 incombination, resulted in higher activity of cat, pod and sod enzymes in thefruits of the examined cultivar