An integrated approach to nutgrass control : SRDC final report NFS002

Abstract

This project aimed to formulate and promote an integrated approach to nutgrass control in sugarcane cropping systems. The project was a Grower Group Research Project undertaken from July 2007 to June 2010 by the NSW Farming Systems Group Inc. and BSES Limited extension officers in NSW. Trials were established to evaluate some best-bet options for nutgrass control. These trials aimed to assess packages of successive treatments all aimed at reducing the viability of nutgrass tubers. Results from these trials were used to extend options for long-term nutgrass control to cane producers. The trial work undertaken and associated economic analysis showed that it is highly economic to control nutgrass in cane. Total control of nutgrass resulted in large dollar benefits ($350-450/ha) and trials evaluating 'one-off' herbicide treatments for nutgrass also showed net benefits of $200-400/ha. This indicates that, even where nutgrass is patchy, growers could outlay $60-100/ha for nutgrass control and still obtain a substantial net benefit. A factsheet/decision support package titled Managing nutgrass in cane was produced and circulated throughout the Australian sugarcane industry. This factsheet emphasises that nutgrass can only be managed using a long-term integrated approach aimed at reducing the number of viable tubers. No single one off treatment will control nutgrass and repeated treatments are the only sure way of controlling nutgrass. A single one off treatment will reduce nutgrass competition in the short term but, because of its ability to rapidly propagate under suitable conditions, repeated treatments are imperative. The factsheet provides options for nutgrass control at various stages in the cane crop cycle.