Sponsorship of 2004-05 Summer Scholarships - Barnett/Kilby

Abstract

"Evaluation of yield component changes in Australian cotton cultivars":The aim of this summer scholarship project was to measure the changes that have occurred in the yield components of Australian cotton cultivars including environmental impacts. It also allows for the importance of each component to be determined in terms of contribution to overall yield. Trials were conducted using six cultivars(DP 16, Namcala, Sicala 40, Sicot 189, Sicot 71 and Sicot 71B) grown in three locations(Boggabilla (near Goondiwindi), ACRI (Narrabri) and Carroll (near Breeza)) representing hot, intermediate and cool climates for growing cotton respectively.

Plant mapping was carried out during the growing season and final harvest data was also measured, but is yet to be collated. Preliminary results from the plant mapping show that the Bollgard® II cultivar was less tipped out than the other conventional cultivars. These conventional cultivars were tipped out over 85% of the time across all three sites. The Bollgard® II cultivar acquired bolls earlier and retained more bolls throughout the season than any of the other cultivars measured. The Bollgard® II cultivar also showed greater reliability at producing a greater number of squares across all three environments. Final harvest will provide data to show whether the Bollgard® II cultivar will yield more than the conventional cultivars, as well as demonstrating how the yield components of Australian cotton cultivars have changed over time. (Kilby) "The effectiveness of Lynx Spiders (Oxyopes amoenus) and Damsel Bugs (Nabis kingergii) at controlling Green Mirids (Creontiades dilutus) in Cotton":The purpose of the experiments conducted were to determine whether the Australian Lynx spider, Oxyopes amoenus, and the Damsel bug, Nabis kingergii, had any potential in the control of the Green Mirid, Creontiades dilutus, in Bt cotton in Australia. The predators and pests were firstly combined to try and determine if either of the predators was effective in mirid control. Secondly, the mirid size preference was determined for each predator and, finally, how many of the mirids the predators could eat before becoming satiated.(Barnett)