ISHS Acta Horticulturae 275: International Symposium on the Culture of Subtropical and Tropical Fruits and Crops
PHENOLOGICAL CYCLING OF MACADAMIAS AND ITS INFLUENCE ON YIELD AND QUALITY OF NUTS |
| Authors: | R.A. Stephenson, E.C. Gallagher |
| Abstract:
The phenological cycle of tree crops provides a useful framework for understanding the complexity of factors influencing yield and quality. Major components of the macadamia phenological cycle in Australia are described. Vegetative growth patterns, the balance between vegetative and reproductive growth, leaf nitrogen (N), boron (B) and storage carbohydrate levels at specific stages all influenced macadamia yields and quality. An early "spring" flush associated with warm nights prior to nut set, followed by a period of vegetative dormancy until after oil accumulation in kernels was complete, was correlated with high yields. Young, actively photosynthesising foliage supported nut growth and oil accumulation, and competition between developing nuts and vegetative growth was avoided. Demand by the developing nut crop rather than the competing spring flushing was primarily responsible for depletion of trunk carbohydrate reserves. High leaf N during oil accumulation in summer and high B during late floral development/anthesis were correlated with high yield. A comprehensive study is being carried out to gain a more complete understanding of nut development and the influence of environmental, climatic and phenological cycling factors on this. The influence of these on crop yield and quality will be assessed over a 3 year period. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
