National PhD scholarship scheme – driving research innovation (LP15007)
What’s it all about?
By awarding scholarships to PhD students from a range of disciplines, this initiative is about encouraging blue-sky, cross-sector research that will benefit the Australian horticulture industry for years to come.
To date, PhD research being supported by the scholarships includes:
- Precision agriculture. Using crop-based sensor and precision agriculture technologies to directly and accurately assess irrigation/fertigation needs in specific areas of a crop, and then meet those needs in a precisely timed and targetted way. Crops anticipated to be involved in the work include avocado, macadamia and vegetables including capsicum and chilli.
- Protected cropping. Looking at the potential to expand protective cropping in Australia's warmer tropical regions, and improve protected cropping in subtropical regions, with a focus on systems to improve crop quality and crop longevity under protected cropping.
This investment enabled PhD student Alison Ctercteko to undertake a doctoral research project and acquire leadership skills through collaboration with Biocontrol Australia and several commercial cherry and grapevine businesses. Alison actively worked on the project for 18 months but, due to a personal change in circumstances, could not continue.
The project consisted of several inquiries aimed at examining the interaction between the biocontrol agent (Trichoderma harzianum) and the pathogen (Botrytis cinerea) in laboratory and field conditions, as well as investigating the factors influencing the growth and survival of the biocontrol. To explore the mode of action of Trichoderma harzianum Td81b against Botrytis cinerea, Alison refined laboratory protocols to investigate the interaction between both fungal species.
She initiated cultures with and without each species to facilitate comparative transcriptomic analysis and identified relevant gene targets for coding. Additionally, Alison established and evaluated field trials to assess the timing of T. harzianum application throughout the grapevine and cherry growing seasons. Disease levels at the time of harvest showed variability and were influenced by the treatments and weather events.
Throughout the season, grape berry samples were collected to examine the survival of the biocontrol using qPCR, but Alison did not analyze them before discontinuing her study. In another aspect of the project aimed at determining the presence of mycoviruses in the biocontrol species, Alison extracted RNA from T. harzianum and sequenced the genome. Initial analysis suggested the absence of mycoviruses, but other approaches were being explored.
The investment supported PhD student Karli Groves from Central Queensland University to complete a doctoral research project and gain research leadership skills through collaboration with a leading Australian vegetable crop producer and attendance at national and international horticultural conferences.
Her PhD project Examining key constraints to protected cropping systems for the production of high-value vegetable crops in tropical and subtropical climate focused on the subtropical / tropical protected cropping industry. It sought to identify and investigate key aspects affecting crop yield and quality in a commercial cucumber production system.
Protected cropping represents great potential for increased yields of higher quality and more sustainably grown produce. Appropriate research expertise to support continued expansion of protected cropping in Northern Australia is currently limited, with most research centred in cooler, temperate zones.
While many crops are grown under protective structures in Australia, cucumber is one of the most economically important and widely grown crops in the country.
Research undertaken in the PhD project identified that fruit displaying bending during early growth (that would normally be removed and discarded by pickers) would straighten if left on the plant. Less frequent pruning delivered higher marketable fruit yields (on average, one additional fruit per plant over the cropping period) than the current pruning strategy and reduced labour costs.
The recommended practice change was implemented by the commercial farming partner, which resulted in increased productivity and profitability.
Karli developed the skills and knowledge needed to make a significant contribution to Australian Horticulture in her future career. She gained employment as a Postdoctoral Research Fellow within the Institute for Future Farming Systems at Central Queensland University, where she will deliver research services to horticultural producers in the Bundaberg region of Queensland.
The final report for Karli’s research can be downloaded here.
The investment supported PhD student Ryan Warren from the University of Tasmania to complete a doctoral research project and gain research leadership skills. As was the program's aim, this project resulted in a formally trained research higher-degree graduate capable of advising industry on honey bee health and crop pollination.
His PhD project, Optimising and applying RFID technology to monitor individual honey bee behaviour in agricultural field settings, focused on developing a radio frequency identification (RFID) system capable of autonomously monitoring individual bees from full-strength hives in field locations. Once designed, a research trial demonstrated the potential of this unique system through the investigation of bee longevity and behaviour in two important horticultural crops: sweet cherry and hybrid carrot seed.
This research provides the first insight into individual honey bee behaviour under a range of polythene and netted crop coverings while also investigating the impact of isolated crops. Overall, the research did not find the practices used in Australian cherry and hybrid carrot seed crops negatively impacting individual honey bee foraging behaviour. The extensive findings of this work have relevance for horticultural producers, beekeepers and researchers.
The final report for Ryan's research can be downloaded here.
This investment supported PhD student Cameron Stone to understand how new protective cropping covers alter the microclimate and how to design orchards and irrigation systems for optimal fruit quality (size, colour, firmness etc.). Cherry fruit quality is of the utmost importance for Australian cherry growers due to their high value in international markets. Measurement of tree water use indicated a three-fold reduction in uptake by trees under Protected cropping systems (PCS) in contrast to under bird netting. Modelling suggests the reduced fluctuation in daily climate predictors (temperature, relative humidity, wind) under PCS provides a more stable environment resulting in less tree water uptake. Subsequent research has highlighted faster fruit maturity further under PCS in contrast to locations in closer proximity to the PCS boundary. It is believed warmer temperatures and the reduction of wind speed influenced fruit quality characteristics with significantly higher sugar levels in fruit closer to the centre of the PCS in contrast to locations near the PCS boundary.
In addition, novel results were found on the effect planar training systems had on light interception and penetration and the subsequent impact this had on fruit yield and quality for the lateral bearing cultivar ‘Kordia’. Results indicated light interception measurements and fruit quality characteristics benefited when sufficient space was permitted between upright/vertical branches within the same tree. Space between trees/upright/vertical branches allowed lateral branches to grow unimpeded by surrounding branches resulting in improved light interception and fruiting sites.
Results from this study highlight the significant impact of novel microclimates created by PCS on tree water uptake and fruit quality in a commercial orchard. The buffering of wind and increased average temperatures and relative humidity under PCS resulted in a significant reduction of tree water uptake in contrast to under bird netting. Similarly, elevation and distance from the nearest PCS boundary impacted orchard microclimates and subsequent fruit quality. Locations furthest from the block boundary that had higher elevation and were warmer throughout the season had more favourable growing microclimates and resulted in better quality fruit in contrast to lower elevation locations closer to the block boundary. Additionally, this study has highlighted that appropriate space is required between tree planting distances or within training system fruiting limbs for lateral bearing cultivars when trained to a planar system. Fruit quality, light interception and light penetration improved when adequate space between branches was available, supporting lateral wood development for flowering and fruiting. While seasonal variations (i.e. climate and crop load) had a significant impact, fruit quality noticeably improved with greater canopy light interception.
Findings are reported for growers and agronomists in two fact sheets: