Avocados need heavy manuring, and application of nitrogen has been found to be most essential. In general, young avocado trees should receive N, P2O5 and K2O in a proportion of 1:1:1 and older trees in the proportion of 2:1:2. At a pH of above 7, iron deficiency symptoms may appear, which may be corrected by applying iron chelate at the rate of 35 g/tree.