Dr C. Owen Gwathmey was invited to Narrabri for an 8 week scientific exchange (Feb-March 2014) to share knowledge in cotton agronomy and physiology and provide mentorship to a new generation of cotton cropping specialists. Dr Gwathmey is a professor emeritus at the University of Tennessee in Jackson specialising in cotton agronomy and physiology. His research has a number of synergies with research undertaken by in Australia, on cotton physiology and management.

The purpose of Dr Gwathmey’s visit was to collaborate with Drs Brodrick and Bange in reviewing worldwide research into row spacing and plant population both which an area of research of continual interest to both U.S. and Australian growers. The review compares findings between studies; discuss possible reasons for differences in plant responses to density in different environments and clearly articulate opportunities where population provides an agronomic solution for improved yield, quality and resource efficiencies.

In February and March, Dr Owen Gwathmey worked at ACRI Narrabri, in an 8-­‐week

Scientific exchange with CSIRO hosted by Dr Rose Brodrick and Dr Michael Bange. During this period Dr Gwathmey attended industry field days, gave a seminar on his research in West Tennessee and met with many industry and research staff. The main focus of his visit was on developing concepts and reviewing data from published and unpublished research on two topics:

• Cotton row spacing/plant density, and

• Timing of crop maturity

During his visit Dr Gwathmey assembled two comprehensive Endnote databases as part of a worldwide review of literature relevant to the topics and we developed substantive outlines on the two topics as the basis for future manuscripts intended for publication and dissemination to growers and industry. Our work on these manuscripts is continuing.

In addition, Dr Gwathmey met with Drs Greg Constable, Shiming Liu and Warwick Stiller to obtain breeders perspective on these topics.

Dr Gwathmey also met with several younger cotton researchers in Narrabri, Katie Broughton, Dr Jenny Clement, Dr Onoriode Coast, Dr Warren Conaty and Dr Nicola Cottee providing mentorship in crop agronomy and physiology to these researchers.

Collaborations between cotton scientists in Australia and the USA have continued as an outcome of this visit with Dr Warwick Stiller visiting the West Tennessee Research Station during a visit to the U.S.A this year.

Dr Gwathmey actively contributed to discussions at field days that he attended during his visit, providing insight in particularly into the fundamental principles behind management for early maturity and mepiquat chloride (Pix) and differences in the climatic conditions in the U.S.A and Australia that might influence management decisions. Feedback from growers and consultants attending these field days was very positive about having access to an expert in this area to provide clarification around some of the management differences between the different environments.