Transforming subtropical/tropical tree crop productivity

Abstract

Orchard intensification of temperate tree crops such as apple, has led to significant increases in productivity. In this research program, we aimed to adapt the principles and management systems that have made these intensive systems so productive to the less developed, extensive orchard systems of subtropical and tropical tree crops. For the work we chose the commercially important avocado, macadamia and mango, because of their high potential for improved productivity. The key components of modern apple orchard systems that allow them to be so productive are orchard light relations, vigour management, crop load, and tree and shoot architecture. Our approach has been to improve understanding of these key components through research, which we used to develop alternative management options and radically redesign orchard production systems. This research used applied field experiments, molecular genetics and plant modelling. A major focus of the program has been large scale Planting Systems Trials for each crop, where we investigated how the key components interacted with each other at different tree planting densities, scion varieties, rootstocks, and tree training systems.