Everything you need to know about sugarcane cultivation and harvest! Learn about:- 1. Origin of Sugarcane 2. Soil and Climate Required for Sugarcane Cultivation 3. Processing and Milling 4. Planting 5. Cultivation 6. Pruning 7. Harvesting 8. Pests.
Origin of Sugarcane:
Sugarcane was originally from tropical South Asia and Southeast Asia Different species likely originated in different locations with S. barberi originating in India and S. edule and S. officinarum coming from New Guinea The thick stalk stores energy as sucrose in the sap. From this juice, sugar is extracted by evaporating the water. Crystallized sugar was reported 5000 years ago in India.
Around the eighth century A.D., Arabs introduced sugar to the Mediterranean, Mesopotamia, Egypt, North Africa, and Spain. By the tenth century, sources state, there was no village in Mesopotamia that didn’t grow sugar cane. It was among the early crops brought to the Americas by Spaniards. Brazil is currently the biggest sugar cane producing country.
A boiling house was used in the 17th through 19th centuries to make sugarcane juice into raw sugar. These houses were add-ons to the sugar plantations in the western colonies. This process was often conducted by the African slaves, under very poor conditions. The boiling house was made of cut stone.
The furnaces were rectangular boxes of brick or stone with openings near to one side, and at the bottom to stoke the fire and pull out the ashes. At the top of each furnace were up to seven copper kettles or boilers, each one smaller than the previous one and hotter.
The cane juice was placed in the first copper kettle which was the largest. The juice was then heated and a little lime added to remove impurities. The juice was then skimmed then channeled to the other copper kettles.
The last kettle, which was called the ‘teache’ was where the cane juice became syrup. It was then put into cooling troughs where the sugar crystals hardened around a sticky core of molasses. The raw sugar was then shoveled from the cooling trough into hogsheads (wooden barrels) where they were put in the curing house.
Sugarcane was, and still is, extensively grown in the Caribbean, where it was first brought by Christopher Columbus during his second voyage to The Americas, initially to the island of Hispaniola (modern day Haiti and the Dominican Republic). In colonial times, sugar was a major product of the triangular trade of New World raw materials, European manufactures, and African slaves.
France found its sugarcane islands so valuable it effectively traded its portion of Canada, famously dubbed “a few acres of snow,” to Britain for their return of Guadeloupe, Martinique and St. Lucia at the end of the Seven-year’ War. The Dutch similarly kept Suriname, a sugar colony in South America, instead of seeking the return of the New Netherlands (New Amsterdam).
Cuban sugarcane produced sugar that received price supports from and a guaranteed market in the USSR; the dissolution of that country forced the closure of most of Cuba’s sugar industry. Sugarcane remains an important part of the economy of Belize, Barbados, and Haiti along with the Dominican Republic, Guadeloupe, Jamaica, and other islands. The sugarcane industry is a major export for the Caribbean, but it is expected to collapse with the removal of European preferences by 2009.
Sugarcane production greatly influenced many tropical Pacific islands, including Okinawa and most particularly Hawaii and Fiji. In these islands, sugar cane came to dominate the economic and political landscape after the arrival of powerful European and American agricultural business, which promoted immigration from various Asian countries for workers to tend and harvest the crop. Sugar-industry policies eventually established the ethnic makeup of the island populations that now exist, profoundly affecting modern politics and society in the islands.
Brazil is a major grower of sugarcane, which is used to produce sugar and provide the ethanol used in making gasoline-ethanol blends (gasohol) for transportation fuel. In India, sugarcane is sold as jaggery and also refined into sugar, primarily for consumption in tea and sweets, and for the production of alcoholic beverages.
Soil and Climate Required for Sugarcane Cultivation:
i. Temperature:
Sugar-cane requires a hot climate with temperatures between 21° and 27°C (70° and 80°F) throughout the year. A dry, sunny season near harvest time is a great advantage as it promotes sugar accumulation.
ii. Rainfall:
Sugar-cane requires abundant rainfall of at least 1 270 mm (50 inches) if it is grown without irrigation. It can however be successfully grown with irrigation in areas receiving only a moderate rainfall. Too much rain tends to dilute the sugar and leads to poor yields.
iii. Soils:
Sugar-cane needs deep fertile soils which are water-retentive. However, soils must be well-drained and damp areas with stagnant water are avoided. Soils must be kept fertile with the use of fertilizers to ensure continued high yields. Sugarcane is usually grown on flat or undulating lowlands to facilitate harvesting, especially where there is a high degree of mechanization.
iv. Labour:
A large supply of relatively cheap labour is required mainly at harvest time. The cane is usually cut by hand and this is very hard and tiring work. In the U.S.A. and to some extent in Australia lack of labour leads to mechanized operations, but hand-cutting is probably more efficient.
Processing and Milling of Sugarcane:
Traditionally, sugarcane has been processed in two stages. Sugarcane mills, located in sugarcane-producing regions, extract sugar from freshly harvested sugarcane, resulting in raw sugar for later refining, and in “mill white” sugar for local consumption. Sugar refineries, often located in heavy sugar-consuming regions, such as North America, Europe, and Japan, then purify raw sugar to produce refined white sugar, a product that is more than 99 per cent pure sucrose.
These two stages are slowly becoming blurred. Increasing affluence in the sugar-producing tropics has led to an increase in demand for refined sugar products in those areas, where a trend toward combined milling and refining has developed.
Milling:
Sugarcane first has to be moved to a mill which is usually located close to the area of cultivation. Small rail networks are a common method of transporting the cane to a mill. Once the factories acquire the cane it will be subjected to the quality test. In Sri Lanka cane will be evaluated according to the brix and trash percentage.
Planting of Sugarcane:
1. Flat Bed Planting:
Shallow Furrow 8-10 cm deep distance 75- 90 cm, generally 3 budded setts, planting by end to end system. Furrow is covered by 5-7 cm soil and field is leveled by planking, popular in north India and some parts of Maharashtra.
2. Furrow Method:
Deep furrows 10-15 cm in north India and 20 cm in south India; Practised in eastern U.P. and peninsular India particularly in heavy soils.
3. Trench/Java Method:
20-25 cm deep trenches at 75-90 cm, give ‘U’ -shaped trench, common in Java, some coastal areas and in areas where the crop grows very tall and strong wind; setts planted either in these trenches or in small furrows prepared in the centre of trenches by end to end method.
4. Partha Method:
In south T.N., Planting of sugarcane is difficult due to rains in July to Nov. and occasional showers upto middle January which results setts rot and buds fail to germinate. To overcome it, Parthasarthy (1961) developed it for waterlogging condition.
Fields is divided into ridges and furrows and 3-budded setts are planted at an angle of 45° on ridges leaving at least one bud above the soil. After 5-6 weeks shoots emerge from bud and after another 5-6 weeks when plant attains a higher of 20-25 cm, the setts are pressed horizontally.
5. Spaced Transplanting Technique:
It was developed at IISR, Lucknow single budded setts are planted in nursery @20q/ha or 18000 setts/ha. After 45-60 days single budded setts are transplanted in main field.
6. Winter Nursery System:
At IISR Lucknow, 3 budded setts are let close together in the nursery bed in the month of December and covered with a thin layer of soil and setts are submerged by water. Submergence should not be more than 2-3 hours. Floating setts are removed. Nursery is then covered with polythene sheets which allow sunshine to pass through it but keeps off air. Within few hours, dew is formed on the underside of the polythene sheet and on cane begins to drop over the setts.
After 5-6 weeks when setts have sprouted, polythene sheets are removed. Such type of setts are called ‘Slip setts’, and the sett rate is @70q/ha for 3 budded thick variety and 50q/ha for thin variety.
7. Rayungans Method:
Indonesian term meaning a developed cane shoot with single sprouted bud. A portion of field is selected for Rayungan production is left at harvesting time. Top of the cane is cut off which results auxiliary buds begin to sprout.
For quick and effective sprouting fertilizer especially Nitrogen in heavy dose is applied and field is irrigated. After 3-4 weeks sprouted buds are separated in a single bud setts and transplanted on ridges. It is costly hence is not commonly adopted in India however is usually used for filling gap.
8. Sablang/Sprouting Method:
Tillers, soon after they develop their own roots, are separated from the mother plant and planted separately. It is successful in Java & Cuba.
9. Tjeblock Method:
Improvement over Rayungan method because it takes care of proper availability of energy and nutrient to all the buds. Here stalks are cut off at its half-length and planted vertically with one node under the soil for rooting. The planted ones and the mother stalks are adequately irrigated and fertilized. Now the upper buds of both Tjeblocks and mother canes, which sprout in due course of time, are planted by cutting them into setts in rayungan.
10. Algin Method:
Upper most nodes are collected while stripping the canes for crushing; then is planted in wheat field in rows after every 4 rows of wheat at 90cm × 50cm. It is evolved by Allahabad Agriculture Institute, Allahabad.
Placing of setts in different ways in the field:
1. End to end method – in this method sett rate is low.
2. Eye to eye method
3. Double Row System – For thicker planting and off-season planting.
4. Single bud planting – Setts having single bud only.
Cultivation of Sugarcane:
Sugarcane cultivation requires a tropical or subtropical climate, with a minimum of 600 mm (24 in) of annual moisture. It is one of the most efficient photo synthesizers in the plant kingdom. It is a C-4 plant, able to convert up to 2 per cent of incident solar energy into biomass. In prime growing regions, such as Peru, Brazil, Bolivia, Colombia, Australia, Ecuador, Cuba, the Philippines and Hawaii, sugarcane can produce 20 kg for each square meter exposed to the sun.
Sugarcane is propagated from cuttings, rather than from seeds; although certain types still produce seeds, modern methods of stem cuttings have become the most common method of reproduction. Each cutting must contain at least one bud, and the cuttings are usually planted by hand.
Once planted, a stand of cane can be harvested several times; after each harvest, the cane sends up new stalks, called ratoons. Usually, each successive harvest gives a smaller yield, and eventually the declining yields justify replanting. Depending on agricultural practice, two to ten harvests may be possible between plantings.
Sugarcane is harvested mostly by hand and sometimes mechanically. Hand harvesting accounts for more than half of the world’s production, and is especially dominant in the developing world. When harvested by hand, the field is first set on fire. The fire spreads rapidly, burning away dry dead leaves, and killing any venomous snakes hiding in the crop, but leaving the water-rich stalks and roots unharmed. With cane knives or machetes, harvesters then cut the standing cane just above the ground. A skilled harvester can cut 500 kg of sugarcane in an hour.
With mechanical harvesting, a sugarcane combine (or chopper harvester), a harvesting machine originally developed in Australia, is used. The Austoft 7000 series was the original design for the modern harvester and has now been copied by other companies including Cameco and John Deere. The machine cuts the cane at the base of the stalk, separates the cane from its leaves, and deposits the cane into a haul out transporter while blowing the thrash back onto the field.
Such machines can harvest 100 tonnes of cane each hour, but cane harvested using these machines must be transported to the processing plant rapidly; once cut, sugarcane begins to lose its sugar content, and damage inflicted on the cane during mechanical harvesting accelerates this decay.
Pruning of Sugarcane:
The Santa Elisa sugarcane processing plant, one of the largest and oldest in Brazil, is located in Sertaozinho, Brazil.
In sugar refining, raw sugar is further purified. It is first mixed with heavy syrup and then centrifuged clean. This process is called ‘affination’; its purpose is to wash away the outer coating of the raw sugar crystals, which is less pure than the crystal interior. The remaining sugar is then dissolved to make syrup, about 70 per cent by weight solids.
The sugar solution is clarified by the addition of phosphoric acid and calcium hydroxide, which combine to precipitate calcium phosphate. The calcium phosphate particles entrap some impurities and absorb others, and then float to the top of the tank, where they can be skimmed off. An alternative to this “phosphatation” technique is ‘carbonatation,’ which is similar, but uses carbon dioxide and calcium hydroxide to produce a calcium carbonate precipitate.
After any remaining solids are filtered out, the clarified syrup is decolorized by filtration through a bed of activated carbon; bone char was traditionally used in this role, but its use is no longer common. Some remaining colour-forming impurities adsorb to the carbon bed. The purified syrup is then concentrated to super saturation and repeatedly crystallized under vacuum, to produce white refined sugar.
As in a sugar mill, the sugar crystals are separated from the molasses by centrifuging. Additional sugar is recovered by blending the remaining syrup with the washings from affination and again crystallizing to produce brown sugar. When no more sugar can be economically recovered, the final molasses still contains 20-30 per cent sucrose and 15-25 per cent glucose and fructose.
To produce granulated sugar, in which the individual sugar grains do not clump together, sugar must be dried. Drying is accomplished first by drying the sugar in a hot rotary dryer, and then by conditioning the sugar by blowing cool air through it for several days.
Harvesting of Sugarcane:
For Proper Maturity:
Spray Balsario chemical @4.5 kg ha-1 in 1000 lit water. The spray of this chemical matures the cane 6-8 weeks earlier. Chemical ripener like Polaris and sodium metasilicate improved the juice sucrose when sprayed on foliage 6 weeks before the scheduled harvest date.
Symptoms for judging the sugarcane maturity:
1. Leaves become yellow.
2. Arrowing and plant’s growth is stopped.
3. Canes become brittle and break easily at nodes.
4. Canes produce metallic sounds.
5. Buds swell out at nodes.
6. Eyes start sprouting.
7. Brix schachrometer/Hand refractrometer- when Brix% reading of middle portion stalk reaches 16-18% (Milliable canes)
8. When glucose content is less than 0.5% tested by Fehling’s solution.
Under high temperature, Sucrose gets converted into glucose and quality of the produce becomes poor).
Pests of Sugarcane:
The most important sugarcane pests are the larvae of some butterfly/moth species, including the turnip moth, the sugarcane borer (Diatraea saccharalis), the Mexican rice borer (Eoreuma loftini), leaf-cutting ants, termites; spittlebugs (especially Mahanarva fimbriolata and Deois flavopicta), and the beetle Migdolus fryanus. The planthopper Eumetopina flavipes is an insect which acts as a vector for the phytoplasma.