Since joining Charles Sturt University (CSU), weeds researcher Professor Leslie Weston has encountered wildlife close-up, meeting a large kangaroo 'eye-to-eye’ when walking across CSU’s Wagga Wagga Campus.

 

It’s an experience she happily recounts as she speaks enthusiastically about moving to Australia from New York state, USA, in July to take up a position as Strategic Research Professor of Weed Sciences at CSU.

 

Professor Weston left Cornell University – one of the United States’s premier research universities - for new challenges at CSU after receiving a prestigious NSW Government Life Science Research Award, which attracts leading international researchers to the State.

 

With links already established in Australia, Professor Weston will expand her ground breaking research into the management of invasive weeds and development of natural plant products that could act as pesticides, fungicides, herbicides or insecticides. “I have a long history working with colleagues in Australia, having known [CSU’s] Professor Jim Pratley and his team for around 15 years, as well as researchers at CSIRO, so it seemed a natural thing to move to Wagga and further our collaborations.

 

I immediately felt right at home because although my previous home town, Ithaca, is smaller and often colder than Wagga Wagga, it’s very rural and surrounded by dairy farms, vineyards, horses and diverse crop production,” she said.

 

 

Professor Weston is internationally renowned for her research in the fields of weed science, allelopathy, natural products chemistry and horticulture. She holds two international patents for natural products with biological activities, which have commercial potential as bioherbicides.

 

“The natural compound, m-tyrosine, which is isolated from Festuca rubra, a perennial fine fescue and turf grass, can suppress the germination and growth of a wide variety of weeds. It could be developed as a bioherbicide, or to help select fescues and related pasture grasses such as perennial ryegrass for better suppression of weeds in the pasture. I am also investigating the potential of other chemicals that might be exuded from grass roots.”

 

Professor Weston says a turf grass that inherently suppresses weeds would be very appealing to the landscaping turf market. “Managers of golf courses, sports athletics fields and home lawns are often reliant on herbicides to manage weeds, so they have been very interested in our findings.”

 

Professor Weston became an academic professor aged 26 years after completing degrees in plant breeding, genetics, weed science and plant physiology at Michigan State University, USA. A researcher for 20 years, she worked for 12 years at the University of Kentucky focusing on horticultural cropping systems and herbicide metabolism and then at Cornell University for nine years where she specialised in weed science and natural product chemistry.

 

 

Professor Weston brings a wealth of experience and knowledge to CSU and sees plenty of agricultural challenges, one of which is the management of invasive weeds. “At CSU I’ll focus on studying the biology, ecology and management of several key invasive weed species including serrated tussock, a major pasture weed and Paterson’s curse, a common annual which is a big problem throughout south-east Australia,” she said.

 

“I’m interested in both native and introduced invasive weeds.  I’m investigating the chemicals that invasive weeds naturally produce which assists them in invading new areas of crops or pasture for example,” she said.

 

This area of research, known as allelopathy, is of broad interest world wide. Allelopathy occurs when chemicals released by one plant species affect other species in its vicinity. An example of a commercially available pesticide derived from natural plant products is pyrethrin, an insecticide which is extracted from a species of Chrysanthemum or lemon grass oil extracts used for weed management by home owners in the US.

 

Allelochemicals are present in nearly all plant tissues and may be released from plants into the environment through the leaves, roots and decomposing leaf matter. When plants are exposed to allelochemicals their growth and development are affected. We now understand that invasive weeds often release allelo-chemicals into the environment.  I plan to study the mechanisms of how weeds interfere with the growth of crop plants to gain a competitive advantage over time, including their successful reproductive strategies as well as allelopathy.

 

Professor Weston will compliment and strengthen an established team at CSU working on weed management issues including Professor Len Wade, who has interests in crop physiology and stubble mulching; Professor Jim Pratley, a weed scientist; Professor Gavin Ash, a plant pathologist working in biocontrol of weeds; and Dr Min An, a natural product chemist. She also will work with researchers in the EH Graham Centre for Agricultural Innovation to set up laboratories in physiology and biochemistry to improve the infrastructure available to support weed science research.

 

 

It is possible her eight year contract with CSU may not be long enough, especially when Professor Weston mentions the other areas where she’d like to make a contribution including the impact of climate change on agriculture, and using cover crops and rotational cropping systems to suppress weeds.

 

“Careful selection of crop rotations and pasture mixes can be used to smother problem weeds and reduce weed seed production over time,” she said. This ecological or systems approach to production is proving important to agricultural producers in Australia who often regard weeds as their worst pest management issue.

 

The impact of climate change on the spread and competitiveness of native and introduced Australian weeds is an area that Prof Weston views as important. “As the climate changes, the environmental stresses encountered by producers have been exacerbated. What kind of impacts will climate change have on major weed species and their ability to invade and reproduce in irrigated and non-irrigated crops? These concerns will require additional research,” she said.