Impact of Silicon in Alleviating Biotic and Abiotic Stress in Sugarcane: a Review

For many years silicon (Si) deficiency in crops was relatively unknown and this element was widely regarded as non-essential for plant growth. Ever since the discovery by D’Hotman De Villiers, in 1937, that sugarcane growing on highly weathered soils in Mauritius could be rejuvenated, by applying finely crushed siliceous basalt, silicon has emerged as an important nutrient for sugarcane. With the exception of potassium, sugarcane is known to take up more Si than any other mineral nutrient, with the potential to accumulate up to 400 kg ha in a 12-month old irrigated crop. This paper documents some of the more important studies and outcomes of research into the Si requirement of sugarcane in countries such as Brazil, Florida, Hawaii, Puerto Rico, Australia, Mauritius and South Africa. Early studies have tended to emphasize the role of Si in alleviating abiotic stress caused by factors such Al and Mn toxicity in soils. Results of field studies conducted in South Africa have shown that four out of five field trials produced significant responses to the application of calcium silicate and these varied from 9 to 24 tc/ha. More recent research has focused on the beneficial role of Si in alleviating biotic stress from factors such as pests and disease.