2016 | Vimpany I | Research report/article
An earlier project (Stephenson et al, 1987) showed that total non-structural carbohydrate (TNSC) increased steeply from nut maturity in late February until flowering and then declined steeply until nuts were mature. This indicated that the tree stored spare carbohydrate during certain times of the crop cycle and used these reserves when demand exceeded supply from photosynthesis. This project investigated the seasonal pattern of TNSC in Hawaiian and Australian macadamia cultivars in Bundaberg and Northern NSW.
2013 | Stephenson R | Research report/article
Development of a functional-structural modelling for macadamia. The project used self-organising model to explore canopy management options. The amount of light available for growth was sensed at the leaf level and used to represent vigour, which was then accumulated acropetally. Buds also sensed the light environment but only to provide demand in subsequent redistribution. Glasshouse experiments assessed the architecture of small macadamia plants from more than 15 ecotypes of five genotypes. A sonic digitiser was used to digitise the small macadamia plants in pots over the time. Detailed information was extracted and their architectural pattern of growth was compared. Photosynthesis of three macadamia genotypes was measured. The effect of rootstocks on micro grafted A4 scion was also studied. Orchard experiments were conducted to determine the relationship between vegetative growth and carbohydrate sources in mature macadamia trees in mid-March and mid-September 2011, coinciding with the two major flushes that are normally produced. A prototype model of girdled and non-girdled branches has been developed to show the contribution of current photosynthesis (leaf area) and the stored carbohydrate pool to new shoot growth on girdled and non-girdled branches.
2011 | McFadyen L, Wilkie JD, Huett D, Olesen T | Research report/article
Final Report Research Project MC04024
2008 | Stephenson R | Research report/article
Final Report Research Project MC06005
2005 | Vithanage V, Schmidt A | Research report/article
Final Report Research Project MC01002
2005 | McConchie C, Salter B | Research report/article
Final Report Research Project MC00029. The current Australian macadamia harvest systems require repeated collection of ground harvested nuts. Harvest delays caused by factors such as poor weather conditions result in kernel deterioration and losses. Ground harvesting also exposes nuts to the risk of biological contamination. To facilitate ground harvest the orchard floors are kept clear enhancing the risk of erosion. The ability to either chemically or mechanically regulate nut drop can reduce the number of harvests, duration of contact with the ground and minimise losses due to poor weather conditions. The aims of this project were: 1) To determine the role of the growth regulator abscisic acid in nut abscission and to discover if there are other ways of removing nuts in a timely and economic manner 2) To investigate whether there are long-term detrimental effects of tree shaking 3) To quantify the effects of nut retention on tree on kernel shelf-life.
2005 | Olesen T | Research report/article
Orchard trees of A4 macadamia and Hass avocado were thinned and tip-pruned at different times to generate a range of trees with different stages of leafy flush development. The difference in phase affected flowering.
2004 | Penter M | Research report/article
Many commercial macadamia cultivars retain their crop on tree past the time of optimum kernel maturity. This time varies between cultivars but is particularly noticeable in Beaumont, which represents a larger percentage of trees planted in South Africa.
2004 | Stephenson R | Research report/article
Final Report Research Project MC02042. To review tree root physiology generally, and macadamia tree root physiology in particular, to identify gaps in knowledge requiring research. In addition, to report on macadamia root studies to provide a benchmark of information to guide future research.
2004 | Alberts D | Research report/article
The possible use of reflecting white barrier films is suggested as an alternative to intermitted sprinkling or avoiding areas which are too hot.
This website has been partly funded by Hort Innovation, using the macadamia research and development levy and contributions from the Australian Government.