Growing and harvesting sugarcane

Here at Ragus, we are intimately familiar with the sugarcane plant. It’s used as a vital raw material in the manufacture of the pure sugars we deliver in bulk to industry and underpins our range of crystalline sugars and syrups.

Over 1.9 billion tonnes of sugarcane are harvested each year. There’s much to know about this fascinating plant and how its use is so critical to global industries such as food and beverages, pharmaceuticals and energy.

Did you know that the famous sugarcane is a type of perennial grass? Part of the andropogoneae tribe of grasses and belonging to the Saccharum genus, this fibrous plant requires tropical and subtropical regions for growth, with non-tropical climates such as the Saharan desert in Australia or the alpine tundra of parts of Chile and Peru being unsuitable for its farming.

Ragus sources much of its raw materials from natural sugarcane. This crop is a tall grass that reaches a height of 4 to 5 metres at full maturity. It requires ample rainfall and abundant sunshine in the summer and mild winters to grow, lending itself well to being an ancient crop of the Austronesian and Papuan people before being introduced by sailors to Polynesia and beyond in prehistoric times.

The crop was also introduced to China and India from 1200 to 1000 BC, with Greeks and Persians describing the crop as the reed that “produces honey without bees”. Nowadays, sugarcane is generally found globally across tropical and subtropical regions, in countries such as Brazil, Cuba, the USA, Mexico, India, Pakistan, Mauritius, Laos, Thailand and Australia.

Sugarcane is a tremendously important global crop. It’s the largest crop by production quantity, with 1.9 billion tonnes produced in 2020 – 40% of that from Brazil alone!

Sugarcane is one of the most efficient photosynthesizes in the entire plant kingdom. As a ‘C₄’ plant – one of three kinds of photosynthetic processes relating to carbon fixation in plants – it is remarkably effective in its ability to convert up to 1% of solar energy it receives into the biomass of the plant itself. All plants capture the sun’s energy through their chlorophyll and use it to produce sugars, with sugar beet and sugarcane producing and storing enough sugar that we can grow them specifically for that sugar.

The cane seeds themselves are too small to plant directly in the field – and some varieties of sugarcane lack seeds entirely. Instead, mature harvested stalks are cut into 20-inch segments, placed in furrows in the field and covered with soil. Three weeks later, sprouts appear. After 12 months, the sugar cane is ready to harvest.

It is possible to harvest several sugarcane crops from the plant. Following cutting, a sugarcane plant will grow new stalks called ratoons. With each successive harvest usually resulting in a smaller yield than the one before it, most sugarcane farmers will opt for a total harvest amount of between two and ten harvests.

This amount varies depending on climate, demand and availability of fertile ground; some areas of France such as the la Réunion island, for instance, will harvest sugarcane repeatedly over several years before replanting.  

Root grubs and termites are common and damaging pests for sugarcane. Management methods vary, with the introduction of beneficial insects such as ladybirds acting as a biodiverse treatment option. In many cases, insecticides such as phorate are used at scale for their cost-effectiveness. Other pests and weeds that threaten the crop include downy mildew, leaf scorch, white leaf disease and mosaic viruses.

The global sugar industry has long been interested in alternate uses for critical crops such as sugarcane. With major businesses involved in its production seeking to push toward both ethical and sustainable farming practices, the potential for the crop to be used more diversely has become a key effort adopted across the world.

One of the most valuable alternative uses for sugarcane is biofuel – or more specifically, biogas. This is a product that is gained when biomass is burned, such as sugarcane itself. Falling under the umbrella term of biofuel, this valuable use of sugarcane is made possible through the crushing of sugarcane stalks. This produces a rich cane juice, which can then be passed into fermentation tanks. In time, yeast fermentation creates a reaction that creates ethanol, which can be used as fuel.

So, there’s a lot of work involved in getting to the point of collection! At this stage, collection typically involves the use of mechanical harvesters that are designed to specifically remove the leafy top of the cane. This is generally stored separately from the stalks, which are also cut into short pieces known as billets.

Then the different parts of the plant are loaded into a series of bins on the harvester and are eventually transported to a sugar mill. This is often done using road transport or tramways for greater efficiency at scale. The next stage on sugarcane’s journey from the field into pure sugar products for industry is extracting juice from sugarcane at the mill.

A fascinating summary of an important crop used by the Ragus team. To learn more about our range of cane syrups and crystalline sugars manufactured for industry, contact our Customer Services Team. To see more sugar news and updates, continue browsing SUGARTALK and follow Ragus on LinkedIn.