Abstract
The effects of N. P. S. Zn + Fe, and a mixture of other plant nutrients were tested in a factorial experiment with irrigated Eucalyptus camaldulensis (Myrtaceae) and Anthocephalus chinensis (Rubiaceae) on an alkaline cracking clay. N gave a highly significant response in height and diameter growth of E. camaldulensis and there was an additional benefit from the application of P. Survival was excellent but borers attacked ? 4% of trees and ? 9% suffered stem breakage during storms. A. chinensis responded to N, but health declined after the first year possibly due to B accumulating to toxic levels. Insect attack was not a problem with this species. E. camaldulensis can be established and grown satisfactorily on a difficult site at Kununurra under irrigation and when fertilized with N and P. The health decline encountered with A. chinensis suggests that problems could arise with B and with E. camaldulensis unless the soil profile is adequately flushed. However, continued irrigation without adequate flushing could accumulate salts to levels which could depress growth.
