The responses of Leucadendron ‘Safari sunset’, on its own roots and grafted on ‘Orot’ rootstock, to a range of fertilization regimes were studied. The experiment was conducted during the summer of 1994, at Bet Dagan, Israel, and included three levels of compound NPK, two levels of P, and two NH4[ratio ]NO3 ratios.
Ungrafted plants fed without P yielded fewest marketable branches and had the lowest fresh and dry weights. Increasing the P concentration in the irrigation water to 10 mg/dm3 improved the yield, whereas increasing the NPK level reduced the number of marketable branches and the fresh and dry weight yields. Lowering the NH4[ratio ]NO3 ratio in the irrigation water significantly reduced the yield.
The grafted plants were significantly better than the ungrafted plants under all the treatments examined. The superiority of the grafted plants was more evident under conditions of P deficiency and non-optimal pH.