
TY  - JOUR
A1  - Sarooshi, R 
A1  - Weir, RG 
A1  - Coote, BG 
T1  - Effect of nitrogen, phosphorus and potassium fertiliser rates on fruit yield, leaf mineral concentration and growth of young orange trees in the Sunraysia district
JF  - Australian Journal of Experimental Agriculture
JO  - Aust. J. Exp. Agric.
Y1  - 1991
VL  - 31
IS  - 2
SP  - 263
EP  - 272
KW  - 
UR  - https://doi.org/10.1071/EA9910263 
N2  - Fruit yield, leaf nutrient concentrations and growth response of young Valencia orange trees to 4 rates of nitrogen (N, 75-450 kg/ha), phosphorus (P, 0-180 kg/ha) and potassium (K, 0-360 kg/ha) were studied using 2 soil management systems (sod-sown and bare ground) and 2 rootstocks (Troyer Citrange and Sweet Orange). Eight-year-old Sweet Orange produced maximum yield at the higher rates of applied N and P and medium level of K, but at 12 years of age, highest yields occurred at the lowest rate of applied N, medium P and nil K. High N without P at year 12 strongly depressed yield especially on bare soil. Phosphorus application at high rates of N greatly increased yield but had no effect at lower rates of N. The effect of nutrients on yield was smaller on Troyer than on Sweet Orange rootstock. Leaf N concentration increased with amount of N applied and slightly increased with K applications but not with applied P. Leaf P concentrations increased with higher rates of applied P, especially in year 12 and at the lowest rate of applied N. Both rootstock and management affected leaf P concentration. Leaf K increased with amount of applied K. Highest concentrations of leaf K were from Troyer trees under bare soil management but this trend declined with time. The effects of fertilisers on tree size were small and varied with rootstock and management. 
ER  -

