Ecology and biology of nuisance algae in rice fields (February 2006)

Grant, A Pavlova, M Wilkinson-White Grant, I Ko, D

2006

This IREC Farmer Newsletter article presensts a summary of the results of a project undertaken in rice on Brown slime. The formation of brown slime is as result of polysaccharides (sticky sugars) forming on the surface of bacteria. Due to their stickiness a variety of organisms and stubble adhere to it this then create large mats on the surface of orange-brown slime. Increase in brown slime are often on grey soil as they are rich in reduced iron; once nitrogen and water are added, iron-oxidizing bacteria, which lead to slime, multiply and the soil colour. The management during rice establishment is crucial to reducing yield losses as a result of slime. This management assists in reducing slime conditions as it is impossible to remove either bacteria or iron from rice growing soil. The article answers the following questions and gives solutions for reducing incidences of slime ; When does brown slime become a nuisance?, What conditions are related to brown slime?, What is brown slime?, How can farmers tell whether their soils are prone to brown slime?, Suggestions for reducing the incidence of brown slime