Utjecaj fertirigacije s dušikom na sadržaj željeza, bakra i bora u listu i rodnost jabuke sorti Jonagold i Golden delicious

Two apple (Malus domestica Borkh) cultivars grafted on M9 rootstock were grown on high density (\u27Jonagold\u27 2500 trees/ha, \u27Golden Delicious\u27 3000 trees/ha). There were five treatments for each cultuvar (fertirigation with 45kg N/ha, 60 kg N/ha, 120 kg N/ha, irrigation without fertilisers, and control- without irrigation and without fertilisers), and two timing variants (treatments during vegetation period from 1 May to 20 June - variant A, and treatments from 1 May to 1 August - variant B). The treatments were impossed beginning in the second year after planting and lasted seven years (1992-1998). Concentration of microelements in leaf was determined over the 7th and 8th growing season. During the season 1997/98 effects of the applied treatments on leaf mineral content were notable, but these effects often were not consistent. There were no significant timing effect on leaf nutrient concetration of both cultivars. During the cropping years (1993-1998) there were no consistent treatment effects for cumulative yield and cumulative yield efficiency. The highest cumulative yield achieved \u27Jonagold\u27 in the control, while \u27Golden Delicious\u27 performed best when it was fertilised with 45 and 60 kg N/ha._