Yield accumulation in sugarcane under wet tropical conditions - effect of lodging and crop age

This study examined crop growth and yield accumulation over time of the variety Q158 under wet, tropical conditions. There were three different treatments: control (natural lodging), scaffolding (non-lodging) and late crop (result of early ratooning in December). Compared with the scaffolding trcatment, a slow-down in biomass accumulation was observed in the control treatment only for a short time after lodging, which led to ] 6% less cane yield in the control treatment than the scaffolding treatment at the September harvest. This was partially associated with lower dry weight of the stalks and partially with stalk death due to lodging. Sugar yields in the non-lodging treatment were 18% to 22% higher than the control, depending upon the time of harvest. This was mainly attributable to higher commercial cane sugar (CCS) concentrations in June and to higher cane yields (fresh or dry) in September. The growth rate of the late (younger) crop, which was influenced by lodging later in the season, was similar to that of the non-lodged crops. Cane biomass production continued in all the treatments until the final harvest in September. The crops did not experience a 'plateau' in yield accumulation, as observed in some studies under tropical conditions. This was possibly due to the warmer conditions experienced and/or the smaller size of the crops (100 t/ha) and/or the response of Q158 to the lodging experienced in this study.