NUTRITIONAL FACTORS AFFECTING PRODUCTION AND QUALITY OF MACADAMIA NUTS IN AUSTRALIA

A survey of well managed, mature productive macadamia orchards was conducted to establish tentative standard leaf nutrient levels for the Australian industry.
Leaf levels of 1.4–1.5% for N, 0.6–0.7% for K, 0.18% for S and 40–75 mg kg^-1 for B are considered to be suitable tentative standards for macadamias under Australian conditions.
Six to seven-month old leaves are sampled in spring after anthesis and prior to the start of the spring flush.
The timing and intensity of flowering, nut set and vegetative flushing were not significantly influenced by time of N application, except when the level of N was increased.
Low N effectively manipulated the vegetative- reproductive balance in favour of the latter.
The desirability of small but frequent applications of N is therefore indicated.
Four foliar sprays of 0.02% B to cultivars Keauhou (246) and Kakea (508) during early nut development increased leaf B levels from ca 25 to 65 mg kg^-1. Yields were increased, except for 246 in one year.

International Symposium on the Culture of Subtropical and Tropical Fruits and Crops

R.A. Stephenson, E.C. Gallagher

https://doi.org/10.17660/ActaHortic.1990.275.70