POINTERS FOR BETTER FARMING AND RESEARCH FROM SUGARCANE PHYSIOLOGY

SUGARCANE PHYSIOLOGY has been neglected for several decades in all cane growing countries including Australia. However an international physiology workshop in 2003 funded by the Sugar Research and Development Corporation stimulated interest in this type of research in Australia and South Africa at least. The proceedings of the workshop were published in an international journal in 2005 and some practical pointers for better farming practice were highlighted in popular Australian industry publications during 2006. In this paper we hope to capture some of the more important aspects of knowledge of cane physiology to compliment the considerable conventional wisdom to be found in the industry. Sugarcane is a deep rooted crop and can make use of water and nutrient resources deep in the profile. This has been clearly demonstrated on commercial farms. The root system is sensitive to compaction which should be limited and controlled as much as possible to allow the benefits of the deep rooting habit to be expressed. Breeding and management should aim for sustained plant population as is the norm in other broadacre crops. While this is difficult to achieve we can start by looking after soil health rather than by changing crop row arrangements unless these contribute to improve soil health. Estimates of water requirements for sugarcane are reliable and can be applied through a scheduling and water management tool like WaterSense. Sugarcane can tolerate some water stress and irrigation management should focus on sugar not cane yield. Photosynthesis is much less sensitive to water stress than stalk elongation and water can be saved making use of this knowledge as well as knowing that roots can access water deep in the profile. Shorter crops could help delay lodging which can reduce yields substantially. Options for manipulating the physiological processes described here will improve as we gain greater understanding of their genetic control.