The present area of sugarcane (Saccarum officinarum) is about 13 million ha with a total commercial world production of about 1254.8 million ton/year cane or 55 million ton/year sucrose. (FAOSTAT, 2001).
Sugarcane originated in Asia, probably in New Guinea. Most of the rainfed and irrigated commercial sugarcane is grown between 35°N and S of the equator. The crop flourishes under a long, warm growing season with a high incidence of radiation and adequate moisture, followed by a dry, sunny and fairly cool but frost-free ripening and harvesting period.
Optimum temperature for sprouting (germination) of stem cuttings is 32 to 38°C. Optimum growth is achieved with mean daily temperatures between 22 and 30°C. Minimum temperature for active growth is approximately 20°C. For ripening, however, relatively lower temperatures in the range of 20 to 10°C are desirable, since this has a noticeable influence on the reduction of vegetative growth rate and the enrichment of sucrose in the cane.
A long growing season is essential for high yields. The normal length of the total growing period varies between 9 months with harvest before winter frost to 24 months in Hawaii, but it is generally 15 to 16 months. Plant (first) crop is normally followed by 2 to 4 ratoon crops, and in certain cases up to a maximum of 8 crops are taken, each taking about 1 year to mature. Growth of the stool is slow at first, gradually increasing until the maximum growth rate is reached after which growth slows down as the cane begins to ripen and mature. The flowering of sugarcane is controlled by daylength, but it is also influenced by water and nitrogen supply. Flowering has a progressive deleterious effect on sucrose content.Normally, therefore, flowering is prevented or non-flowering varieties are used.
Sugarcane does not require a special type of soil. Best soils are those that are more than 1 m deep but deep rooting to a depth of up to 5 m is possible. The soil should preferably be well-aerated (after heavy rain the pore space filled with air > 10 to 12 percent) and have a total available water content of 15 percent or more. When there is a groundwater table it should be more than 1.5 to 2.0 m below the surface. The optimum soil pH is about 6.5 but sugarcane will grow in soils with pH in the range of 5 to 8.5
Sugarcane has high nitrogen and potassium needs and relatively low phosphate requirements, or 100 to 200 kg/ha N, 20 to 90 kg/ha P and 125 to 160 kg/ha K for a yield of 100 ton/ha cane, but application rates are sometimes higher. At maturity, the nitrogen content of the soil must be as low as possible for a good sugar recovery, particularly where the ripening period is moist and warm.
Row spacing varies usually between 1.1 and 1.4 m; number of sets per ha depends on the number of buds per set and may vary between 21000 and 35000.
Sugarcane is moderately sensitive to salinity and decrease in crop yield due to increasing salinity is: 0% at ECe 1.7 mmhos/cm, 10% at 3.3, 25% at 6.0, 50% at 10.4 and 100% at ECe 18.6 mmhos / cm.
The graph below depicts the crop stages of sugarcane, and the table summarises the main crop coefficients used for water management.