HAWAII AGRICULTURAL EXPERIMENT STATION 
HONOLULU, HAWAII 
Cadet the joint supervision of the 
l NITED 8 I kTES DEF 1RTMENT Of AGRICULTURE 
and the 
I n | \ ERS1 I V OF It \\\ MI 
BULLETIN No. 7!) 
Washington, I). C. \|>ril 1938 
METHODS OF EVALUATING THE MACADAMIA NUT 
FOR COMMERCIAL USE AND THE VARIATION 
OCCURRING AMONG SEEDLING PLANTINGS IN 
HAWAII 
By .J. C. Hi ppjbrtom , Chemist, H. H. Mmm/m , Principal Agricultural Aide, and 
I). W. EiDWARDB. Junior ( fit mist 
l ONTENTS 
Page race 
[ntsoduction i Evaluation of nuts from d iiTerent seedling treea 
The rough-shell and smooth-shell types of mac- from diflerenl localities n; 
adamia nut - 
Methods of evaluat inir macadamia nut- 
Evaluating commercial samples of macadami i 
uuts by the quahty-jatio method 
Discussion 21 
Summary 23 
Literature cited 23 
Appendix a 1 ) 
l\ I Koi) I CTION 
The macadamia has been grown in Hawaii as isolated trues or small 
orchards since the time of its introduction about 1892 (7). 1 Not 
until 1922 was an attempt made to grow the nut for commercial use. 
A stock company was formed and sizable plantings were made on 
two islands, Oahu and Hawaii. With this impetus other interests 
have made appreciable plantings in many locations on the several 
islands. The present plantings comprise about N()() acres containing 
about C)(),()()() trees, most of which are less than 15 years old. In 1031 
;i factory was built and machinery, specially developed for processing 
the macadamia as a roasted vacuum-packed article for the world 
trade, was installed. 
At the time this investigation was begun no data existed as to the 
nature or extent of variation among macadamia seedlings. Plantings 
in Hawaii have consisted entirely of seedling trees, the seeds being 
taken from certain of the old trees of the Territory known to yield 
well and to produce nuts of good quality. 
The same general situation appears to exist in Queensland and New 
South Wales, Australia, where the nut is indigenous. Most of the 
crop comes from the native "bush" and the largest bearing orchards 
i Italic numbers in parentheses refer to Literature Cited, p. 23. 
26S4<; — :;8 1 
1 
