SCREENING FOR BORER RESISTANCE AMONG SUGARCANE CLONES IN PAPUA NEW GUINEA, 2010�2012

PAPUA NEW GUINEA (PNG) has several damaging moth borers that are not present in Australia, but which would almost certainly cause very serious losses in our sugarcane industry if they reached this country. To prepare for a possible incursion, Australian varieties and promising clones are being tested for their susceptibility to these borers in field trials at Ramu Agri-Industries, PNG. Two trials were planted in 2010 (32 clones) and 2011 (33 clones) and sampled for borers in the plant crop (both trials) and the first ratoon (2010 trial only). There were highly significant differences among clones for internode damage from Sesamia grisescens and Chilo terrenellus and stalk damage from Scirpophaga excerptalis. Generally, there was a greater difference among clones for damage from S. grisescens and S. excerptalis than from C. terrenellus. The twelve standard clones in these trials were also present in trials planted in 2002 and 2007, which were sampled for borers in the plant crop (both trials) and the first ratoon (2002 trial only). Comparing results of the six data sets, consistent differences among the standard clones were apparent for S. grisescens and S. excerptalis but were less clear for C. terrenellus. Estimates of damage from each of the three borers are presented for some Australian commercial varieties. Other commercial varieties will be included in trials to be planted in 2013.