Diagnostic leaf analysis for stone fruit. 5. Sweet cherry

Abstract

Changes in the nutrient-element composition of leaves of 'St. Margaret' cherry were measured monthly during the 1971-72 and 1972-73 seasons in New South Wales. The rate of change of leaf composition was least during January-February. Thus, leaf composition standards should be based on January- February samples and diagnostic sampling should be confined to this period where possible. Correction factors for adjusting the composition of early or late samples back to January 31 levels were calculated from polynomials with time fitted to the leaf composition data. A survey of the leaf composition of well-managed orchards was conducted each January from 1971 to 1973. Nutrients were found to be low or deficient in the following percentages of the orchards surveyed : nitrogen 37; phosphorus 31 ; potassium 37; calcium 25; iron 43; and zinc 62. High levels of copper were found in 9 per cent and of manganese in 15 per cent of the orchards.