engleski

Effect of foliar nitrogen fertilization on leaf nitrogen status of cv. Graševina (Vitis vinifera L.)

Nitrogen fertilization is a regular agricultural practice as it affects vine growth and yield as well as grape and must nitrogen content. It also has an impact on the fermentation rate. Common viticultural practice includes soil application. The aim of this study was to determine the effect of foliar application of three different nitrogen forms on grapevine nitrogen supply, indicated by leaf nitrogen status. Study was conducted on cv. Graševina (clone ISV-1) grafted on SO4 rootstock. It was carried out in 2012 and 2013 on Jazbina trial field of the Faculty of Agriculture in Zagreb (Zagreb winegrowing region) using latin square design. The trial consisted of five treatments: K (no fertilization), NPK (250 kg/ha winter soil application), Drin (NPK soil+foliar 0, 25% Drin), UR (NPK soil+foliar 1% urea) and AN (NPK soil+foliar 0, 25% ammonium nitrate). Foliar fertilization was repeated in four growth stages: 8 leaves separated, before flowering, berries pea-size and after harvest (according to modified E-L system). Prior to every treatment, leaf samples were taken and leaf total N was determined according to Kjeldahl method. Foliar N fertilization positively affected the leaf N status, but its effect depended on N form applied. The highest result was obtained by UR treatment, which significantly increased total leaf N compared to K and NPK treatment. Obtained results indicate positive effect of foliar N application in order to improve grapevine N supply.

foliar fertilization; leaf nitrogen; growth stages; Graševina

nije evidentirano