Macadamia integrifolia - Smooth macadamia

Description and Uses

Macadamia integrifolia (Smooth macadamia) is a tropical tree from Northern Australia . It is mainly grown for its nut crops , which have a long shelf life. The crop is harvested by ground gathering. It starts flowering after 7 - 9 years. The yield will be 10kg/tree, but in its top season there will be a yield of 30kg/tree. Other crop types include; nut, ornamental, oil, apiculture, . The seed/nut is used as delicacy . The seed/nut is used as " plant part " with oleic acid (53% - 67%) as its significant phytochemical. There is macadamia oil extracted by cold pressing from the tree's seed/nut yielding 60% - 70% oil. The tree's wood is called macadamia wood and has a density of 550 - 800 kg/m³. Regarding firewood production the tree's growing speed is slow, it's energetic value is 3000 ckal/kg and the wood's drying speed is medium. After 30 years the tree can be totally removed as it reached its commercial and ecological goal. Macadamia integrifolia has a lifespan of 200 years.

Environmental limitations

The tree is 18 meters tall with a crown of 15 meters wide. The tree prefers a planting distance of 600 cm and a row distance of 1,000 cm. It is slow growing and intolerant to shade. Macadamia integrifolia has a shallow root-system and it has symbiotic associations with the Glomus intraradices and Glomus mosseae fungi (endo-mycorrhiza). It is not able to fix nitrogen with "any bacteria. The name(s) or string of bacteria include(s) "not applicable ". The tree's flower-morphology is hermaphroditic and is pollinated by bees. Macadamia integrifolia is evergreen and not allelopathic and has no thorns.

Macadamia integrifolia thrives in an altitude of 0 to 1600 meters above sea-level (tropical). The minimum temperature is 1°C; optimally between 15 - 25°C. The optimal rainfall is 2200 mm/year. Without irrigation the annual rainfall should be between 700 - 3000mm (L/m²). The optimal soil-pH is between 5.0 - 6.0 in a soil texture of loam. To salt it is intolerant to wind intolerant and to fire intolerant.

Pests and Diseases

Macadamia integrifolia is susceptible to the following pests: Xylotrechus smei , Xystrocera alcyonea , Xystrocera festiva , Xystrocera globosa , Zeuzera coffeae . And it's susceptible to the following diseases: Bacterial blights , Bacterial spot , Downey mildew (blue mould) .

Seed Propagation

Seeds are recalcitrant and can be stored for 4 months. There are approximative 325 seeds/kg. The seeds can be propagated as followed:

• (1) Store harvested seeds in water or in the fruit at room temperature
• (3) Remove the seeds from cold to a permanent warm temperature.
• (3) Seeds germinate above ground (epigeous)