Effect of ratoon stunting disease (RSD) on sugarcane yield in Fiji

Abstract

Sugarcane (Saccharum officinarum) ratoon stunting disease (RSD) caused by bacterium Leifsonia xyli subsp. xyli causes huge (29% or more) in sugarcane ratoon crops. It cost farmers thousands of dollars. A study was conducted to minimize these losses using various hot-water treatments to sugarcane sets before sowing in the field. The differences in cane yield were recorded with all the treatments in the cane yield loss experiment but the differences were not statistically significant. It was observed that the only notable effect of the disease was on the cane yield but very little effect on the sugar and percent of pure obtainable cane sugar (% POCS). The cane yield for the plant (first crop) and subsequent ratoon crops (third year, fourth year, etc.) differed with an average reduction of 37% but the average loss caused by RSD was 29%. Out of the two hot water treatments the best duration of hot water treatment was identified as 2 hours at 50°C because it gave a higher average yield compared to the control (untreated) and 3 hours at 50°C. Three hour duration seems to affect germination of sets and thus total plant population which eventually results in low yield of sugarcane and thus total pure obtainable cane sugar (POAC).