SUGARS FOR RATOON GROWTH-SUGARS WITHIN THE UNDERGROUND STOOL STRUCTURE TO GERMINATE RATOON GROWTH (POSTER)

SUGARCANE IS A perennial with a crop that can be harvested yearly. The regrowth, ratoon, of the plant relies on the sprouting of below ground buds. The below ground architecture of the stool is being investigated in relation to ratoon growth. The initial period of sprouting requires the supply of carbohydrates for growth, before the plantlet can accumulate its own supply. The concentration of sugars within the stool structure were examined in varieties Q242A, Q208A and Q238A grown in commercial fields. Glucose and fructose concentrations ranged from 2 to 15 and 2 to 9 mg/g fresh matter (FM), respectively, and sucrose from 50 to 125 mg/g FM, between the three varieties. There was no significant difference between the top (closer to the soil surface) and the bottom of the stool structure, except in stalk ‘a’ of Q242A, which may have started decaying. Different stalk positions/classifications within the stool also did not show any significant differences. There was also sufficient moisture, 75 to 86 %, within the setts to initiate the sprouting of the buds, with no significant differences between stalk classification and sample location. These results support that there is sufficient moisture and carbohydrate present within the stool structure and is not a limiting factor for the sprouting of viable buds under favourable conditions.