I recently attended the 14th Protected Cropping Australia conference, (the 10th which I have attended), and it was by far the best.
It was held at the Adelaide Convention Centre (South Australia) from 9 to 12 July, and provided attendees with a mass of information, and also the very important opportunity to network with other growers, the servicing industries and researchers.
Protected Cropping Australia (PCA) is the industry body, which services commercial hydroponic and aquaponic greenhouse growers in Australia, and they hold a conference every two years at different venues within Australia.
In total 431 delegates attended the conference. The main sponsors were Apex Greenhouses (which originated as Faber Greenhouses in New Zealand) and the Dutch company Royal Brinkman. There were a total of 67 exhibitors, primarily from Australia, but also some from overseas, including New Zealand: the Hamilton based electronic fruit grader BBC Technologies, Palmerston North’s Redpath Greenhouses, and Haygrove Tunnels from Masterton. There was also a Chinese greenhouse manufacturer, Beijing Kingpen, the fertiliser company Yarra, and a coir company from Sri Lanka, BrownGrow. Of course many of the Australian exhibitors were linked directly to large international companies.
The conference (as is usual) was divided into a first day of plenary presentations, concurrent general sessions the second morning and then broke up into five specialised sections for the rest of second day: fruit and vegetable vine crops, leafy greens, floriculture, aquaponics, and berries. This restricted the chances of attending more than a small number of the final day’s presentations.
The conference was formally opened by the Assistant Minister for Agriculture and Water Resources, Senator Anne Ruston, and then the conference proper began. The keynote speaker was Dr Katherina Adamitza from the LED (light-emitting diode) light company Valoya in Finland. Her topic was “LED and light quality in plants”.
There were three other papers on Plant Factories and Artificial Lighting (PFAL as it is now commonly called), but Dr Adamitza’s paper was by far the most authoritative.
She described how light affects plants because the light energy is transferred by photons which are then sensed by photoreceptors within the plant such as phytochromes and cryptochromes,
and then trigger the start of important metabolic processes such as photosynthesis and so on. These photoreceptors are sensitive to specific wavelengths, for example blue light stimulates stomatal opening, red light photosynthesis, and UV-A (ultraviolet A) light enhances pigment accumulation. LEDs differ from HPS (high pressure sodium) and metal halide lighting, and because they are monochromatic offer the potential to target specific wavelengths. However Dr
Adamitza concluded that since nothing is as good as nature, it is important to imitate the light source of the sun with LED lighting as qualitatively as possible. This is a statement that I for one would strongly disagree with!
I gave the next paper – on medicinal cannabis – and this was followed by Graeme Smith who spoke on vertical farming based on his attendance at conferences in Singapore and Panama. (Is the Sky Greens project in Singapore a PFAL? Certainly when I visited it some years ago, there were no artificial lights, and the growing medium was soil.)
Later the first morning James Altmans from Biological Services, South Australia, presented a paper in which he posed the question of how best to optimise Integrated Pest Management (IPM) in the future. He raised the spectre of new pest incursions (such as the Tomato Potato Psyllid, the Tomato Red Spider Mite), and suggested not to use heavy chemical control unless it was to meet export quarantine requirements (as in New Zealand). He also posed the possibility of using insect pathogens (such as fungi, bacteria or viruses) to control insects (such as B thuringiensis), and new release methods for bio-control agents using sachets and so on. With the trend towards the protective cropping of berryfruit, the value of the cucumeris mite and persimilis mite are becoming very apparent.
In the final paper before lunch, Kelly McJannett of Food Ladder gave an inspiring account of how greenhouses could support impoverished communities. Food Ladder is an Australian based not-for-profit organisation working to address food security using climate controlled greenhouses. It is apparently a model which works in two very diverse environments: impoverished slum areas in India, and remote indigenous communities in Australia. In the afternoon session, Wim van Esch of Achmea, Australia, explained the need to manage and mitigate the risk of product liability. Something that many people have never considered, but something which is becoming more and more relevant with improvements in product traceability. This involves initially identifying the risks involved in your business, and establishing a risk management framework. Ton Habraken from Ludvig Svensson then presented a fascinating paper on the underestimated effects of outgoing long wave radiation on your greenhouse crop. Essentially >
this was a plea to use screens to control the outgoing long wave radiation, in order to ensure that the plants grow effectively. He explained how on clear nights the top of the plant could be well below the desired optimum temperature, so that not only would transpiration slow down (or cease) and calcium not reach to cells at the tip of the plant, but also that guttation could occur, and with it a risk of fungal diseases.
Marcel Bugter of Yara has a well-deserved international reputation for his knowledge of the efficient use of chelates in hydroponics. He explained very clearly the need to use chelates to ensure that the plant roots are able to absorb adequate iron. He suggested that the use of compound chelates incorporating manganese, zinc and copper in the iron chelate was far superior to using a simple iron chelate with copper, manganese and zinc sulphates, as the pH (acidity/alkalinity) close to the plant roots can frequently get to pH 6 or even pH 7.
Finally the day concluded with Jeffery Pouw of Hermadex Agro discussing “Ideal Light – Shading/Diffusion”. He explained how shading simply reduces the overall light intensity, whereas the use of diffusion coatings on the glass ensures that the light is spread more evenly throughout the greenhouse, and more importantly, that diffusion results in deeper penetration of light throughout the canopy.
At the conference dinner on the Monday, Don Grant from Tasman Bay Herbs gave us a fascinating account of his life, which included being a postmaster (of a very small Southland post office), a tour bus driver, and finally a herb grower. This was followed by the presentation of the Protected Cropping Australia awards, with Saskia Blanch the company secretary of the PCA being presented with a well-deserved award for her 25 years of service. Graeme Smith, Rick Donnan and Leigh Taig received the Industry Training award, while Len Tesoriero was made Researcher of the Year. Marcus Brandsema was presented with the Chairman’s award, and Steffan Krauhaar the Young Achiever award, while Ian Mortlock became the Grower of the Year. The Best Trade Exhibit award was given to Grow systems Australia, and Apex Greenhouses was given the New Product award for their innovative ‘retrack sliding roof system’..
The second day provided me with a limited opportunity to attend the wide range of presentations because they all ran concurrently. I gave two presentations myself , one on “Fruit Growing in the Future” (see The Orchardist, 72(3), 11–14) and
one on “Aquaponics – Food for the Future or Flawed Concept?” and I was only able to attend a few of the other presentations.
I was particularly impressed with John Leslie from Vertical Farm Systems, Queensland, who gave a Churchill like presentation offering nothing but blood, toil, tears and sweat. In other words, vertical farming is not that simple. I was less than impressed with Young Han from Enza Zaden in Korea, who provided a less than critical review of lettuce plant factories. A series of pictures from different places does not provide a useful paper unless there is a sound commentary.
In the concurrent sessions on the Tuesday morning, Sonny Moerenhout of Grodan suggested that water is the challenge of the future, and that stone wool and hydroponics is a possible solution. Ian Gesche of Starfish Initiatives considered the emerging opportunities and challenges for greenhouse carbon dioxide enrichment in relation to a changing landscape of increasing costs for natural gas, of climate change, and the shift towards renewable energy sources. David Cavallaro of Stoller, Australia, described how nutrients influence the growth of plants through their effect on plant hormones, and >
Ton Habraken of Ludvig Svensson explained how climate screens can be used to optimise plant growth in hot climates. Rick Donnan then presented his paper on the fundamentals of hydroponic management, and Sohum Gandhi of Enriva suggested that temperate climate heating systems in which the CO2 produced by burning gas is used in the greenhouse during the day ánd the hot water stored for night-time use, might not be appropriate for Australia, and that liquid CO2 might be a better solution. Graeme Smith then gave a talk on the fundamental principles behind greenhouse management, clearly based on his training programmes, and full of useful information. After morning tea it was time for the specialised interest groups. The Vine Vegetables group heard Dion Potter of Syngenta describe different crop protection options, while Marcus van Heijst of Priva described the first of the robots for greenhouse work – a deleafing machine. The future is already here! Farm biosecurity was the subject of Len Tesoriero’s presentation, and he emphasised that plant biosecurity is essential in order to protect the investment. In support of this concept, Jonathan Lidbetter suggested that grafting of cucumbers should be evaluated on a case-by-case basis. Finally Ivan Casteels of Cutilene emphasised the importance of fibre in stone wool.
In the Leafy Greens section, Len Tesoriero spoke on Downy Mildew downunder, and veteran Rick Donnan told us all about start-up solutions for hydroponics – basic but essential knowledge. To conclude the afternoon, Harry Turna of Rijk Zwaan, Australia, gave a general view on new hydroponic developments throughout the world, with an emphasis on urban farming. Graham Grant of Wardell Hydroponic Lettuce then reflected on the use of IPM on leafy greens. He concluded that although IPM is far from perfect (and is certainly not the silver bullet) it has some welcome benefits, including a stronger social license.
In the Berries section my presentation on “Fruit Growing in the Future” (see earlier) was followed by Sophie Parks’ presentation on “Consumer Preferences for Blueberries”, in which she found that flavour attributes are a major factor and the belief that berries are “healthy and good for me”, and “taste good” are very important drivers, while expense is a major barrier to purchase.
Nicky Mann then gave a presentation on berry production in greenhouses,
later to be followed by her husband Wade Mann speaking on IPM for greenhouse berry crops. Both Nicky and Wade gave excellent presentations, and obviously gained a great deal of valuable information from their (separate) Nuffield Scholarships. A further paper by Sophie Parks opened up a potentially important research area, the effect of thinning flowers to increase blueberry fruit size and flavour. The results are still not clear, so the jury is still out on the commercial potential of fruit thinning.
In the Flower section Nicky Mann spoke on “Surviving and Striving in the Australian Flower Industry”. She concludes that flowers are part of a global economy, and with threats will come opportunities. Mark Massey of Polito Farms described the conversion of a family run flower business near Sydney from the field to a hydroponic greenhouse operation. This type of change is very challenging to both workers and management, and the difficulties were not fully appreciated at the time the changes were made. Sonia Bitmead of Currey Flowers then presented a paper on a topic that should be relevant to everyone – succession planning. She emphasised that this involves the transfer of leadership, managerial control, and ownership of family farming assets from one generation to the next. How can this be achieved and those involved also survive as a family? Good question. Rick Donnan then presented a paper on behalf of Herman Eijkelboom (Netherlands) who was unable to attend, on the influence of pH and EC (electrical conductivity) on flowers.
The section on Aquaponics began with Wilson Lennard who addressed one of the major criticisms of this growing system – the difficulty of creating appropriate hydroponic analogues in aquaponics. Dr Lennard stated that the food supplied to fish in an aquaponics system does not provide plants with adequate levels of potassium, calcium and phosphorous, and also provides plants with excessive levels of nitrogen. He proposed that by using a refined mass balance methodology, 95% of the nutrient requirements of the plants can be supplied through fish waste products. Jenny Ekman from Horticulture Research Australia then turned aquaponics on its head and asked can we turn vegetable waste into fish food? She proposed that black soldier flies, yellow meal worm, super worm, and house flies might provide a possible solution. One obvious fact is that fish are consumed not only for their protein, but also for the valuable omega 3 fatty acids which are derived by fish from algae. Andrew Bodlovich of Urban Ecological Systems then proposed that lessons could be learnt from ancient Chinese integrated farming systems, and concluded that we should remain open to modern technology, while at the same time not forgetting ancient agriculture and the principles of holism.
The aquaponics section concluded with my critical views on whether aquaponics was food for the future, or simply a flawed concept.
On the Wednesday, two optional farm visits were available. The first (which I took) was to visit Ppetual Pty Ltd, and then the Yalumba Nursery, while the alternative visits were to the Waite Research Institute and the historic town of Hahndorf in the Adelaide Hills. It had been intended to visit other greenhouse tomato growers, but the concern over the Tomato Potato Psyllid in Western Australia resulted in them being quarantined.
At Ppetual we observed two tomato crops, one just finishing and the other just starting to flower. Ppetual has recently had Apex build 2ha of state-of-the-art greenhouses, with all the necessary bells and whistles to produce heavy high quality crops. At the Yalumba Nursery in the world renowned Barossa Valley we were shown how the rootstocks were selected and trimmed, and then how the grafting was undertaken using an automatic grafter to ensure a close fit of scion and rootstock.
▴ Boiler house at P’Petual.
▴ Browngrow coir from India (left), Royal Brinkman (middle), Haygrove (right).
◀ From top to bottom: Apex, Redpath Greenhouses, Beijing Kingpen, Agspec, Yara fertilizer.
Vine grafting machine.
◀ Boiler house at P’Petual (top), Vine graft (bottom).
q Clause/Hazera (top), De Ruiter/Seminis (bottom).
◀ Dr Adamitza (left), Ms Kelly McJannett (right).