Clean cane with nitrogen fixing bacteria

Abstract

A clean cane is sugarcane is free from all known sugarcane diseases. The importance of using disease-free clean cane as the planting material in commercial production of sugarcane is well-known. The productivity increase could be more than 50% depending on the disease and variety involved. An efficient way of producing clean cane involving the combination of hot water treatment (HWT), thermotherapy and meristem tip culture is mentioned here. This method is well accepted in Brazil. The importance of the nitrogen fixing bacteria (NFB) to the growth of plants is also well-known and the inoculation of Rhizobium, the soybean’s NFB is a common practice in the soybean culture in Brazil, dispensing totally the need of application of N-fertilizers during the production cycle. In the case of sugarcane, 3 NFBs have been isolated by Dr. Dobereiner’s group and were found to be quite common in Brazilian sugarcane varieties. These are theHerbaspirillum rubrisubalbicans, Herbaspirillum seropedicae andAcetobacter diazotrophicus. All of them are endophytic and exist in high amount in stem, leaf and root of sugarcane. HWT is believed not to have an effect on the NFB in sugarcane, while meristem tip culture could clean the NFB as well as other microorganisms. However, NFB is very easy to be re-inoculated into sugarcane. Spraying NFB on cuttings during planting before covering was found possible for this purpose, and clean cane was found to be infected more easily than non-treated cane. Thus, clean cane with NFB could be used as an efficient material for sugarcane commercial production under biological nitrogen fixation conditions.