Vol. 80 No: 6

Title:
Effects of copper, zinc and urea on defoliation and nitrogen reserves in nursery plants of almond

Authors:
G. BI, C.F. SCAGEL, L. CHENG and L.H. FUCHIGAMI

pp: 746-750

Abstract:
´Nonpareil`/´Nemaguard` and ´Nonpareil`/ ´Lovell` almond (Prunus dulcis (Mill) D. A.Webb) nursery trees were used to study the effects of foliar applications of CuEDTA (Cu), ZnSO4 (Zn) and urea on defoliation and nitrogen (N) reserves. Foliar application of Cu and Zn induced early defoliation, with one spray as effective as two.Trees receiving Cu were defoliated 20-30 d before controls and defoliation on trees sprayed with Zn occurred 10-14 d before controls. Urea increased the efficiency of defoliation by Zn (1.25-2% ZnSO₄) and Cu (0.5% CuEDTA). Trees receiving defoliants contained 4-26% less N than naturally defoliated controls, and N reserves were higher in trees given urea than in controls. Trees sprayed with urea plus defoliants contained up to 20% more N than controls. Both CuEDTA and ZnSO₄ promoted early defoliation in almond trees, while the addition of urea can assist in maintaining tree N reserves.

Full text: JHSB Subscribers     ISHS members & other users
(PDF 116358 bytes)

Translate:

Go back to previous page