EARLY PERFORMANCE OF AUSTRALIAN AND HAWAIIAN
MACADAMIA CULTIVARS IN THAILAND

Supattra Supamatee, Philip J. Ito
1
and Damkerng Jalichan
Highland Agriculture Office, Horticulture Research Institute,
Department of Agriculture, Bangkok, Thailand

First published in Proceedings of the First International Macadamia Research Conference; Kona Hilton, Kailua-Kona,
Hawaii, USA; July 28-30 1992; pp. 107-111

ABSTRACT. Ten macadamia cultivars (Macadamia integrifolia) were planted in 1985 at fifteen locations throughout
Thailand. Initial data show that the better locations for macadamia are in the north where average minimum temperatures
were 16.8 to 19.0C and maximum temperatures were 23.1 to 30.6C. In the south, trees grew well and trunk girths for most
cultivars were comparable to the north but few produced flowers. Highest yield of 3.7 kg/WIS, was by 'Own Choice' at
Chiang Rai. Kernel size for most cultivars exceeded 2 g at Wawi and Doi Muser while at Fang and Chiang Rai size was less
than 1.5 g. Likewise, grade No. 1 kernel recovery at Wawi and Doi Muser was 30% or more, at Fang and Chiang Rai it was
less than 30%.

Seeds of Macadamia integrifolia (Maiden et Betche) were introduced into Thailand in 1953 and seedlings planted at Fang
in 1955 and at Doi Muser in 1957 (Trochoulias, 1985). In 1968 several Hawaiian cultivars were grafted at Fang horticultural
experiment station (Ito, 1988). These trees were planted in a poor location where yield and quality were erratic. After
providing good drainage and better maintenance, yield of the best tree was 30 kg of wet-in-shell (WIS) nuts.

At present there are about 100 hectares of macadamia planted. More plantings are anticipated with the increasing interest in
macadamia (Ito, 1990). However, there is no reliable data for macadamia performance such as recommended cultivars and
locations for Thailand.

The project was initiated in 1985 by Damkerng Jalichan to address some of these problems. Grafted plants were imported
from Australia by the Highland Agriculture Research Office of the Department of Agriculture for testing at fifteen selected

Avg. Min. Temp. (C) 25.4 22.9 22.6 19.0 18.4 17.7 16.8
Z
SW = Southwest NE = Northeast LN = Lower North SE = Southeast UN = Upper North

Cultivars
Grafted trees were planted in 1985 and consisted of ten cultivars. Australian cultivars were 'Own Choice' (OC), 'Hinde' (H2)
and 'Hybrid H.Y'. 'Keauhou' (H.A.E.S.
2
246), 'Ikaika' (333), 'Kau' (344), 'Kakea' (508), 'Keaau' (660), 'Mauka' (741) and 'Makai'

1
Professor, Department of Horticulture, University of Hawaii at Manoa, Hilo, Hawaii 96720, USA
2
Hawaii Agricultural Experiment Station selection number (800) were commercial cultivars developed and grown in Hawaii. Trees were planted in a replicated block design with four
replicates consisting of one tree of each cultivar. Trees were spaced 5 x 10 m with buffer trees around the entire field.
Irrigation was provided as needed and 16:16:16 N:P:K fertilizer applied three times a year. Weeds were controlled and a light
grass mulch applied under the trees. Trees trained to a central leader but at some locations branches were excessively
removed for propagation. Intercropping with coffee, asparagus and banana was practiced at some locations.

Growth
A good indication of vigor of macadamia trees is the girth (circumference) of the trunk. This girth was measured 60 cm
above the ground and listed in Table 2. Growth in the warmer southern area was comparable to that of the cooler northern
areas. Trees grew well at Chiang Rai but did poorly in hot, dry areas of the north.

The cultivar most susceptible to high temperatures in the south was 'Kakea' which was stunted, had yellow leaves and at
some locations died. However, in cooler northern areas, it did well with growth equal to other cultivars. 'Keaau', 'Hinde' and
'Mauka' had larger girth while 'Keauhou' and 'Hybrid' had smaller trunk girth.

Chiang Rai yielded the most, averaging 1.9 kg per tree for all cultivars followed by Wawi with 0.7 kg and 0.4 kg at Fang and
Doi Muser. The most productive cultivars were 'Ikaika', 'Hybrid H.Y.', 'Own Choice', and 'Hinde'.

Table 3: WIS yield of five year old Australian and Hawaiian macadamia cultivars in Thailand.
Cultivars Locations
Chiang Rai Fang Doi Muser Wawi Avg std dev
(g/tree)
246 960 409 297 889 638.8 334.4
333 3484 1207 486 1483 1665.0 1283.4
344 854 434 282 246 454.0 278.8
508 - - 443 556 499.5 79.9
660 1287 342 447 1170 811.5 485.8
741 2127 367 469 555 879.5 835.2
800 438 109 213 200 240.0 139.9
HY 2843 - 367 374 1194.7 1427.5
OC 3711 155 278 111 1063.8 1766.2
H2 1115 277 596 1715 925.8 622.7
Avg 1868.8 412.5 387.8 730.0 - -
std dev 1215.9 341.3 119.5 561.9 - -

At Doi Muser and Wawi, major flowering occurred in September to October and matured nuts were harvested in March to
April. At Chiang Rai and Fang, flowering occurred in February to March and nuts matured in August to September.
Flowering and fruiting at Doi Muser and Wawi seem more similar to Kona, Hawaii and as the trees mature, nuts will be
produced throughout the year.

Kernel Quality
Kernels weighing from 2 to 3 g are considered ideal for processing while kernels less than 1.5g are considered too small and
those greater than 3.5 g too large for cans or bottles (Ito et al., 1980).

Kernel size for several cultivars at Wawi and Doi Muser was over 2.0 g. At Fang and Chiang Rai kernel size averaged 1.3 g or


Cultivars performed differently at the sites and the best WIS yield 3.7 kg. was produced by 'Own Choice' at Chiang Rai.
Kernel size for most cultivars exceeded 2 g at Wawi and Doi Muser while at Fang and Chiang Rai kernel size was less than
1.5 g. Likewise, recovery of no. 1 kernels at Wawi and Doi Muser were 30% or more but at Fang and Chiang Rai quality was
poor.

Relative yield of No. 1 kernel (WIS x % No. 1 kernel) by cultivar and site (Table 6) was included by editor for comparison
purposes.

Table 5: Percent recovery of No. 1 kernels from Australian and Hawaiian macadamia cultivars in Thailand.
Cultivars Chiang Rai Fang Doi Muser Wawi Avg std dev
246 - 28 30 19 25.7 5.9
333 27 28 23 23 25.3 2.6
344 23 21 31 29 26.0 4.8
508 - - - 21 - -
660 27 27 36 33 30.8 4.0
741 26 26 31 37 30.0 5.2
800 18 33 20 35 26.5 8.7
HY 26 - - 22 24.0 2.8
OC 27 30 - 36 31.0 4.6
H2 28 29 30 28 28.8
Avg 25.3 27.8 28.7 283 - -
std dev 3.3 3.5 55 6.8 - - Table 6. Relative yield of marketable kernels from 5 year-old macadamia trees in Thailand
z

Cultivars Locations
Chiang Rai Fang. Doi Muser Wawi Avg