Understanding the effect of harvester speed on subsequent ratoon performance in the Burdekin : Final report 2014/092

Abstract

In 2014 six harvester speed trials were established in the Burdekin to investigate the effect of harvester speed on crop yields and subsequent ratooning, and the economics associated with harvesting at different speeds. These trials came about after discussions with growers identified harvester damage as a major cause of yield loss in ratoons. The trials compared the recommended best practice harvesting speed of 7-8 km/h to lower speeds (5-6 km/h) and higher speeds (9 km/h or higher).

The trials commenced in plant cane blocks, and concluded with the second ratoon harvest in 2016. Statistical analysis of the crop yields and changes in yield generally found no correlation between harvester speed and yield or the changes in yield from one year to the next. The only significant effects were noted in the change in yield in between the first and second ratoon crops, at sites 1 and 5. However, at both of these sites there were issues with the irrigation management which have affected the overall yield and potentially compromised the results.

The economic analysis showed that harvesting costs initially decrease as speed increases from a very low speed (5-6 km/h) up to around 9 km/h. Above 9 km/h the costs increased in some cases and decreased in others.

At the conclusion of the project there has been no obvious effect of harvester speed on crop yield or ratooning. There are some trends in the economic analyses, but these are not consistent when the harvesting speed is greater than 9 km/h. This suggests that while growers perceive harvesting speed to be the major factor affecting yields and ratooning, other components of the farming system can have as great an, or greater, effect than harvesting. It also demonstrates the difficulty of isolating and testing the influence of one part of the farming system on yield.