Growth Stages of sugarcane
Sugarcane, a C4 plant, is considered as one of the most efficient convertors of solar energy. It has five growth phases-
- When cultivated commercially, sugarcane is propagated only vegetatively by stem parts (Cuttings) or by whole stems.
- Seed propagation is employed only in selection.
- Planting cuttings should have at least three buds.
- The sprouting phase (the beginning is marked by 10% and the complete stage by 75% pf sprouts) is thought to commerce when two leaves appear on the stem.
- Tillering of sugarcane in the tropics begins soon (in about 15-20 days) after the first sprouts appear.
- The secondary sprouts are formed from underground buds.
- In early ripening varieties of sugarcane, tillering lasts for 4-6 months, and finishes after the row contact.
- In the late-ripening varieties of sugarcane, tillering lasts long as 6-8 months.
- Every new sprout appears in 2 to 4 days.
- Under field cultivation each plant develops :
(a) In the strong-bushy varieties 20 to 40 sprouts
(b) In medium-bushy 15 to 25 sprouts
(c) And in weakly-bushy 8 to 12 sprouts.
Grand Growth Phase
This stage lasts for 5 to 8 months. Sugarcane plants normally vegetate at this stage, if properly supplied with heat and moisture.
- Grand growth phase starts from 120 days after planting and lasts up to 270 days in a 12-month crop. During the early period of this phase tiller stabilization takes place. Out of the total tillers produced only 40-50% survives by 150 days to form millable cane.
- Most important phase of the crop wherein the actual cane formation and elongation and thus yield build up takes place.
- Leaf production is frequent and rapid during this phase with LAI reaching around 6-7.
- Under favourable conditions stalks grow rapidly almost 4-5 internodes per month.
Fig: Grand growth phase
Maturation and Ripening
- This phase lasts for about three months.
- Its maturation is determined by a definite sucrose level in the stems (up to 14-16% stem mass) and a low level of reducing sugars.
- The commercial ripening of stems can be identified quite reliably by the ratio of refractometry indices of juice taken from the seventh-eighth internodes and lower (0.95-0.98). In tropics, by harvesting time the sugarcane stems accumulate on the average up to 14-16% sugar; in subtropics 8-12% sugar.
Submitted by kanchannainwal1 on Tue, 04/08/2009 - 12:21