Posts Tagged ‘ horticulture ’

Horticulture demands new deal for pesticide minor use

Key horticultural industries are stepping up the pressure for a better deal on minor use pesticides. Currently, horticulture producers are stymied by an inefficient pesticide regulation system that they say is inequitous.

“The system is long overdue for an overhaul,” said Dr Stephen Goodwin, the coordinator of a submission endorsed by nursery and garden, strawberry, protected cropping, mushroom, banana, herb and spice and new rural industries, plus CropLife, the association representing chemical manufacturers. They have lodged a comprehensive submission detailing reforms to deliver sustainable minor use crop protection solutions for Australia’s agricultural industries with the Federal Government’s Product Safety & Integrity Committee.

“Under the current Agvet Code, minor use industries have had to make do with temporary permits to gain legal access to many new pesticides and pesticide uses requiring renewal every 2-5 years. The cost of this is borne by the end user or producer, rather than the chemical company,” said Dr Goodwin.

“This is all down to the fact that minor uses do not make sufficient money for chemical manufacturers to warrant the expenditure on registration,” he added.

Dr Goodwin said that horticulture falls into this category because it is made up of a large number of small industries. Despite horticulture as a whole being the third largest Australian agricultural producer with an annual farm gate value at $8 billion, behind only meat and grains, individual commodities have their own pest and disease issues that need to be effectively managed in a sustainable way.

“The current permit system places them at a distinct disadvantage and affects their competitiveness,” said Dr Goodwin.

The horticultural industry’s minor use submission contains a proposal for a new national crop protection program that will make a significant contribution to the pesticide regulatory review to develop a single, national regulatory framework for Agvet chemicals. The proposal is based on the Canadian minor use and pesticide risk reduction programs introduced following similar industry representations prior to 2003.

The Canadian government, under the Federal Agricultural Regulatory Action Plan, provides significant funding on a 5-year cycle to assist the national regulator, the Pest Management Regulatory Agency, to enhance its capacity and improve its efficiency and effectiveness. Funding is also provided to the national research body Agriculture and Agri-Food Canada, to undertake research trials to develop essential data to assist risk assessment. In excess of $CAN55 million has been provided for the period 2008-13. This follows the pioneering US IR-4 program introduced in 1963, and is accompanied by moves by the EU to introduce similar government funding for a minor use program in Europe.

“The tragedy and destruction wrought by a range of natural disasters hitting Australia in recent months make it an inopportune time to be seeking Federal funding in Australia, however, there can be no greater concern for consumers than food security,” Dr Goodwin highlighted.

“Producers and consumers alike will expect the current pesticide regulatory reform proposed by horticulture to be given the highest priority to restore producer competitiveness and guarantee continuing supply of high quality fresh farm produce that Australian consumers have come to expect.”

For further information contact:
Dr Stephen Goodwin,
Biocontrol Solutions
Ph: (02) 4374-1641
MB: 0408 442 062

Katunga Fresh

When it came to moving their family and hydroponic growing operation to Australia, native Hollanders Peter Van der Goor and his wife Marjan didn’t hesitate. Today the Van der Goors run Katunga Fresh, a succesful tomato growing operation in Victoria’s Goulburn Valley.

In Conversation: Ben Van Onna on industry future

Ben van Onna, Senior Trainer PTC+, gives an insight into the future of Australian horticulture over the next 2-5 years.

Researchers give green thumbs up for treated coconut coir

New research by Agri-Science Queensland shows nursery and cut-flower producers can actually grow plants more cost effectively using treated coconut coir potting mix, rather than the less expensive untreated varieties.

Agri-Science Queensland’s Dr Rachael Poulter said the use of coir (fibre made out of coconut husks) as a potting mix by the nursery and cut flower industries was increasing as it was affordable, sustainable, lightweight, and retained moisture.

“However, the process of treating coir results in a more expensive final product than the untreated version, so many producers have been favouring untreated coir based on price alone,” she said.

Over the past year, Agri-Science Queensland has put this to the test by researching, for the industry’s wider benefit, the productivity and cost/benefit differences between treated and untreated coir products.

“Funded through Horticulture Australia Limited, the aim of the project was to quantify differences of growth, yield and quality of gerberas grown in different treated and untreated coir products. We found there were significant effects on plant health, growth, yield and quality between those grown in treated and untreated coir. Overall, the results showed that when it comes to value for money as well as quality growth performance, treated coconut coir is the best option.”

Dr Poulter said a field trial was conducted under protected cropping practices in which three growing media were compared in terms of total productivity and flower quality parameters such as stem length, flower diameter and vase life.

“The coir supplied with no pre-treatment or buffering produced significantly fewer flowers than those grown in a pine bark/coir mix or the pre-treated coir,” she said.

“While the pine bark/coir mix produced a greater number of flowers, the flowers generally had shorter length stems than those grown in treated coir.”

A cost benefit analysis shows the higher return from better stem length outweighs the increase in stem numbers, giving a cost:benefit ratio of 2.58 for treated coir, 2.49 for untreated coir, and 2.52 for pine bark coir mix, for every single dollar spent.

“While this does not seem a large difference, when considering the number of plants a nursery or flower grower might maintain, there is potential significant cost savings from using treated coir instead of untreated coir,” she said.

“Using this cost-ratio calculation in the case of a grower maintaining 50,000 plants, the difference in revenue from using treated coir instead of untreated coir could amount to more than $60,000 per annum.

“The main conclusion drawn from this study is that favouring untreated coir products based on price alone is a false economy, she said.”

Dr Poulter said further research was recommended to assess the products over a longer time period, and using a wider range of plant species.

Agri-Science Queensland is a part of the Department of Employment, Economic Development and Innovation.  Ω

Issue 111: Keeping it Clean

March/April 2010
Author: Christine Paul

According to a leading authority on greenhouse and hydroponic horticulture, maintaining rigorous hygiene practices in the greenhouse is critical to reducing costs and losses in the management of pests and diseases.

Jeremy Badgery-Parker provides an extension service on all aspects of greenhouse and hydroponic production.

Jeremy Badgery-Parker (BScAgr MBA) is the Extension Horticulturist for greenhouse and hydroponic horticulture with Industry & Investment NSW (I&I NSW). He provides an extension service on all aspects of greenhouse and hydroponic production and is involved in a variety of research and extension projects focused on the long-term development of the protected cropping industry in NSW and Australia.

Current projects include developing a business analysis and greenhouse benchmarking program for growers, investigating alternate energy sources and improving greenhouse energy efficiency, water treatment and recycling, low-cost retrofit options for greenhouses locally and in the Philippines, as well as an ongoing focus on improving general greenhouse management and implementing better pest and disease management practices. Jeremy works out of the National Centre for Greenhouse Horticulture (NCGH), Narara, on the NSW Central Coast.

“I have been involved in a HAL project looking at improving awareness of preventative pest and disease management practices. Several workshops have been run in NSW and some in SA and one in Queensland so far and the project is coming to a close shortly,” he says.

Supported by HAL and AusVeg, the project was set up to provide greenhouse growers with the basic information and skills needed for integrated and preventative pest and disease management and to assist them in overcoming barriers to adoption when implementing the foundations of integrated pest management (IPM).

Jeremy is the author of Keep it CLEAN – Reducing costs and losses in the management of pests and diseases in the greenhouse – a comprehensive guide for growers aimed at helping them establish and maintain good hygiene strategies in the greenhouse.

“The Keep it CLEAN manual – as well as some other resources, including factsheets describing 10 essential management practices describe in detail what growers should be doing in terms of good greenhouse hygiene practices,” he says.

10 essential practices for all growers
The series of HAL fact sheets are designed to show how simple, low-cost changes around the greenhouse can significantly reduce costs and losses from pests and diseases. Outlined in the fact sheets are 10 essential practices for every farm:

1. Be able to correctly identify pests and diseases (or have them identified for you) and routinely conduct a pest and disease check to ensure early detection and correct identification of problems.

The simplified pest and disease check is easy to complete because
the greenhouse is set up in advance with marked zones.

2. Action points are determined and pest and disease check information is used for all decision-making including chemical, biological, whole-crop and hot-spot treatments.

3. The greenhouse is within a ‘clean’ zone, which is quarantined from the ‘outside’ zone of the farm.

4. Check and control points are used to control movement of people, vehicles, plants and materials into the ‘clean’ zone.

Roads and paths around the greenhouses need to be kept clean and free of plants, plant material, soil and other debris.

5. Employees and visitors do not visit another greenhouse before entering your greenhouse.

6. All seedlings are checked and found free from pests and diseases before they are planted out into a clean greenhouse.

7. A 5-10 metre-wide clean buffer area is maintained around the greenhouse.

8. The greenhouse is always cleaned and disinfected before planting new crop.

9. The greenhouse and farm surrounds are kept weed-free.

A 5-10 metre weed-free buffer area is needed around every greenhouse on the farm.

10. Crop debris is removed and stored/disposed of outside.

Prevention is cheaper than treatment
Clearly, the profitability and productivity of a greenhouse can be significantly improved by minimising the losses caused by pests and diseases.

“Preventative pest and disease management is about planning, cleaning and quarantining. No single practice on its own can completely prevent pests and diseases causing losses to your crop and to your business,” Jeremy says.

Keeping the greenhouse clean and tidy is a must for all growers and keeping the floor covered makes pest and disease management even easier.

“The key to cost-effective pest and disease management is integrating the most suitable strategies from all the available options and establishing a solid prevention program.

“Integrated pest management, or IPM, is the use of multiple tactics to contain pests and diseases to tolerable levels,” he says.

Every aspect of growing a good crop is part of an integrated pest and disease management program and preventative practices make up the majority of management tactics available to growers.

“Monitoring the crop regularly and routinely enables you to find pests and diseases early. This means you will have more management options available to you,” he says.

“Do a pest and disease check in every greenhouse at least twice a week in summer and once per week in winter. Inspect at least 12 plants per greenhouse and use sticky traps.

“Set up each greenhouse beforehand and mark check points in your greenhouse to make the job easier. Use pre-prepared charts to keep record keeping fast and easy,” Jeremy advises.

“Checking pest numbers routinely enables growers to reduce the number of spray applications. For example, one grower now averages two fewer sprays per crop, saving hundreds of dollars.”

Talking greenhouse hygiene
In the following, Jeremy Badgery-Parker further shares his extensive knowledge of greenhouse hygiene strategies with PH&G readers:

PH&G: What are some of the most common mistakes growers make in terms of greenhouse hygiene?
JBP: One of the most common mistakes growers can make with respect to greenhouse hygiene is taking a short cut. The investment of time and resources into cleaning and maintaining a greenhouse and developing good hygiene practices and farm management policies can be, and is often, completely undone with a single oversight, such as not using a footbath properly or ducking back into a greenhouse to get something without ensuring that clothes, footwear or tools are clean.

The ‘Keep it clean’ project provided foot baths to participating growers. Every person entering a greenhouse must place both feet into the footbath each and every time they enter.

PH&G: Are there any extra precautions hydroponic growers should take?
JBP: Greenhouse and hydroponic growers have an important production advantage in that the production system can be completely clean and pest and disease-free at the start of the crop, unlike field or soil-based production. This pest and disease-free status needs to be protected especially because incoming problems can potentially spread faster if they get into a clean environment.

Another advantage of many hydroponic systems is that plant root zones can be kept separate to minimise the risk of diseases spreading. Growers should, where feasible, ensure that the way their hydroponic system is set up provides effective drainage and prevents root to root contact by plants.

PH&G: When checking for pests and diseases are there any crops that require more frequent monitoring than others?
JBP: All crops need to be routinely inspected – monitored – for pests and diseases. At a minimum, a pest and disease check needs to be conducted twice per week in the warmer months and at least once per week in the cooler months. Monitoring and making a record of pest and disease levels is one of the most valuable pest and disease management practices anyone can do – it is the cornerstone of effective pest and disease management in any crop.

A very simple pest and disease check procedure as well as example charts that make record keeping extremely fast and easy are described in the Keep it Clean manual.

PH&G: Can you describe how ‘action points’ are important in any greenhouse hygiene strategy?
JBP: Action points – sometimes called threshold levels – are a method of pre-planning a pest or disease management strategy. They are set points that you use to make decisions about what, if any, management action you need to take.

By creating a decision point and an action to follow if that point is reached, growers can establish objective responses and benchmarks that not only enable effective and timely management but also greatly improve efficiency, reduce costs and provide a measure by which future actions can be further improved.

Action points go hand-in-hand with effective monitoring. A number of examples are given in the Keep it CLEAN manual to illustrate how they work. The more accurate your action point, the more cost-effective your management of pests and diseases will be.

PH&G: What are some of the most common diseases and pests hydroponic growers need to monitor?
JBP: A number of key pests and diseases commonly occurring in greenhouses in Australia are described in the Keep it CLEAN manual. Effective management of pests and diseases depends on knowing the problem. Preventative practices rely on understanding the problems, knowing the sources of key pests and diseases in and around the farm and being aware of the risk factors.

Thrips, mites and whiteflies are common pests that are far more readily managed when routine monitoring is used to identify early incursions and likely sources. Recognising the early signs of diseases are important and regularly checking a sample of plants in every greenhouse gives a grower the capacity to pre-empt outbreaks and ensure appropriate hygiene practices are being followed.

PH&G: Since the HAL fact sheets were published, have there been any updates growers should know of?
JBP: No, though it is worth noting that the fact sheets are available online. There is also a farm review workbook plus an order form for a copy of the manual [see below].

Request your copy of Keep it CLEAN
Keep it CLEAN is a comprehensive guide for greenhouse growers that lists and describes more than 70 management practices that can significantly reduce the costs and losses that can result from pests and diseases.

The guide also includes practical information on key pests and diseases, assessing the risk of different problems, conducting simple pest and disease monitoring and developing action plans to implement new management practices.

For your copy of Keep it CLEAN – published by NSW Department of Primary Industries – go online: or email:

The guide (normally $33 incl. GST) is available FREE of charge to Australian vegetable-levy-paying greenhouse growers.

Issue 100: Wild Storm Shreds Lettuce

May/June – 2008
Author: Steven Carruthers

Wild storms and floods are a natural part of the Australian landscape but they bring with them devastating consequences including distress and disruption to business and livelihoods. STEVEN CARRUTHERS reports on recent extreme weather events in Queensland with a focus on risk management strategies for growers.

The weather bureau reported wind speeds of 150kph.

Open-air hydroponic lettuce and herb growers in south-east Queensland ducked for cover when a wild storm ripped through Harvey Bay, Maryborough, Childers and Bundaberg in early February 2008. Although the weather bureau reported winds of 150kph, estimates in the Childers region put the wind speed much higher. The violent wind snapped large gum trees, flattened fences, crushed NFT growing tables, and shredded crops. The only good news was the dams are overflowing.

Business partners Brian Ellis (left) and Dan Buckley inspect the crop damage.

The network of lettuce and salad growers under the ‘Clean Green’ label reported two hydroponic NFT farms severely damaged with crop losses of 75%, and two farms moderately damaged with a combined crop loss of 20%. The collective damage bill, including clean-up costs, was estimated at over $100,000. Although the growers had infrastructure insurance, they were not covered for clean-up costs or crop losses.

Fallen trees and flying vegetation caused much of the damage.

The wild storm brought with it hail and heavy rain, but it was the driving wind that snapped tree trunks, stripped branches and defoliated towering gum trees that caused much of the damage.

“The whole district was flattened, strewn with broken trees and native vegetation,” said Brian Ellis, the principal grower at Clean Green Hydro.

“It did quite a lot of damage to our farm including damage to fences, several growing tables, one shed, refrigerated vehicles, and it shredded 75% of our crop. The financial loss will be quite heavy, but we have a very solid business and we will survive and prosper,” he added.

Violent winds snapped gum trees that in turn crushed NFT tables.

Brian said that the damage could have been a lot worse. A bamboo windbreak planted along the front of the 5ha property acted as a wind shield to a degree. Additionally, the building structures are cyclone rated and survived the storm, except one shed that was damaged by a fallen gum tree. Unfortunately, the refrigerated vans were parked near large gum trees and there wasn’t enough time to move them. The damage was extensive.

The 5ha Clean Green operation was strewn with broken trees and native vegetation.

The propagation nursery was protected to a large extent by the pack shed nearby, which was cyclone rated. However, some of the growing tables were not so lucky and were crushed by fallen trees and branches. The wild wind also shredded the majority of the lettuce and salad crop on those tables left standing.

“With the storm travelling from north to south, the same direction as the tables, the damage wasn’t as bad as it could have been if the wind was travelling east-west,” commented business partner Dan Buckley.

While the district experienced a complete power failure, the Clean Green operation had purchased an automatic back-up power generator from Brisbane-based Genelite a few weeks before Christmas 2007.

Fortuitously, the generator had been calibrated by technicians only a few days before the storm struck, and it kicked in flawlessly within minutes of the power failure.

“The ‘gen’ equipment sensed the power failure and automatically switched the generator on to power the refrigeration shed, RO equipment, computers, pump sheds and lights. The main problems were keeping the tanks from overflowing and filters from clogging,” Dan said.

In a land frequently ravished by droughts and floods, Australian farmers are renowned for their resilience and hydroponic growers are no different. Typical of many rural farmers, Brian and Dan put a brave face on their loss.

“We can shut down and totally sterilise most of our salad systems,” Brian remarked. “This is the first time in 6 years that we have been able to do this and it will be like starting new again.”

“We recently tried to work out how to get rid of a few trees that we felt were a danger, but we were having trouble doing this due to the closeness of infrastructure. Now the problem is solved,” Dan added.

Unlike many industries, there are no counselling services to help rural farmers and their families through the emotional turmoil following a force majeure. As would be expected, Brian and Dan went through a kaleidoscope of emotions when they inspected the damage to their salad farm operation.

“That first 24 hours was a head spin, flat-out trying to clean up and make sense of it. I was enroute from Brisbane when the storm struck and it was dark when I arrived back at the farm. The next day I had time to look around and take stock; that’s when reality really set in. That was the hard day,” reflected Brian.

Despite the crop losses, customers, suppliers and employees stuck by the Clean Green team who were back in business and harvesting fresh lettuce and salad crops within three weeks of the storm.

“Times like this give us renewed appreciation for our friends, family, employees, customers and suppliers. They have all been great,” said Brian.

“Dan rang our employees the evening of the storm. The next morning they were all there early with a number of our friends with chainsaws and trailers to assist with the clean-up. We have a great team and are very appreciative of them. They worked their butts off that day in hot and extremely humid conditions.”

“This industry can wear you down after a few years and it sometimes takes something like this to motivate us into mentally regrouping ready for a new charge,” continued Brian. “We will learn from this, make a few changes and move forward,” he added.

Clean Green Hydro is insured by AON Risk Services (, a farm insurance specialist underwritten by CGU.

Farm vehicles were extensively damaged.

“They were excellent,” commented Brian. “I rang our Bundaberg-based broker on Friday and left a message. He called first thing Saturday and arranged for one of our vehicles to have a new windscreen fitted that day so at least we had a fridge van for Monday. He made sure he was contactable throughout the weekend, which made things much easier for us. The assessor arrived first thing Monday morning and was also very efficient.”

Growers can expect more extreme weather events

In addition to wild, violent storms, growers in Queensland and northern New South Wales have been inundated with heavy rains and floodwaters since late December 2007, with two-thirds of Queensland underwater and declared national disaster areas. How quickly the landscape has changed following a prolonged drought.

At its height, floodwaters covered two-thirds of Queensland.

The heavy rains were the result of intense monsoon troughs that swept across northern Australia during the 2007-08 monsoon season. If you talk to the locals they will tell you this year’s wet season is how it was before the drought. However, it would be foolhardy to think the seasons are normalising. At a recent climate change workshop organised by Growcom, an advocate organisation for the Queensland horticulture industry, grower delegates were warned to expect more intense storms and heavy rainfall for some time yet.

Flood waters can take several days to flow downstream.

According to south-east Queensland parsley growers Lisa and Ray Crooks from Riverview Herbs, the heavy rains need to happen to replenish the under-ground aquafiers and to fill many dry dams.

“This will create sustainability in the long run,” said Lisa.

“We were fortunate with the floods,” she continued. “The local river normally sits at half a metre, reached the 15 metre mark and luckily didn’t reach over the banks. Our issue was the back-up water from the river covering the entrance to the farm. This only lasts about two days when it happens.”

Floodwaters inundate this grower camp in the Beaudesert district.

Lisa and Ray own two farms in the Beaudesert district growing parsley in the ground and in raised hydroponic media beds. As long-time growers, they have experienced the emotional rollercoaster ride that comes with drought, storms and flood and they have developed some fundamental risk management strategies to minimise potential damage.

“When flooding is predicted, a lot of the harvested (plant) stock is bought back to this farm and stored in the cold room,” explains Lisa. “Ray has been a great weather man for many years; I knew he was expecting a great wet this year because I got my first clothes dryer for Christmas.

“When he prepares the land for summer, he always hills up the media rows as high as he can go,” she added.

Lisa advises that the internet is a great farming tool. For Australian growers, she recommends the Bureau of Meteorology ( The Bureau’s weather services encompass a wide range of forecasts, warnings, current weather observations and information services to the general public, national and international shipping and aviation, the Department of Defence and other groups. A number of offices around the country issue forecast warnings and other weather information and maintain a 24-hour, seven days a week weather watch service.

“From this website, we watch the weather, and forecasts, the rainfall data, and the river heights. We can have no rain here, yet up on the range further down the Logan River they may have a downpour which we can expect to see in two days time with rising river levels.

“As growers you try to implement risk management strategies as much as possible but no matter how hard you work, the likelihood of being affected by floods, mini cyclones, hail, etc., is a reality at some time during your farming life. It is how you deal with the situation that matters most,” she said.

Risk management strategies
So what can growers learn from these events to prevent or minimise farm damage during bad weather and extreme weather events?

Weather monitoring
By monitoring the weather growers can prepare for bad weather by ‘battening down the hatches’. For floodwaters and violent storms, this means sandbagging flood prone infrastructure and securing all loose items so that they don’t become flying missiles or floating obstacles. During Cyclone Tracy that devastated Darwin on Christmas eve 1974, the coastal buildings suffered little damage compared to inland structures that were flattened by a wave of flying debris that multiplied the further the cyclone travelled inland.

The weather bureau is also the first place growers should go before building new infrastructure to support hydroponic and greenhouse operations. The bureau offers detailed historical weather statistics for regions throughout Australia. However, violent storms and floods can and do occur anywhere and anytime in Australia, from the alpine regions of Tasmania to the tropical rainforests of northern Australia, and everywhere in between. Extreme weather events can also be unpredictable and arrive unexpectedly.

Building guidelines
Valuable information on building codes and local regulations can be obtained from your Shire Council. Greenhouse and system installation suppliers are also happy to supply technical information to back up the strength and integrity of their designs. More building guidelines can be found in the publications, Building a Greenhouse and Guidelines for the development of controlled environment horticulture, available from the NSW Department of Primary Industries ( Collectively, this information should give growers a clear understanding of what sort of infrastructure is required to withstand an extreme weather event in your region. Be sure to check the 100-year flood level.

Risk management strategies can also include the establishment of windbreaks, which should be located a suitable distance away from farm infrastructure to prevent crop shadowing as well as crop and building damage from falling trees. Check with your district horticulturist for the most suitable tree species to plant for windbreaks in your area.

Tree and shrub windbreaks are also valuable conservation tools with many functions. Their benefits include:
• Crop protection – Windbreaks can increase crop yields up to 44% ( Wind protection reduces crop water use, increases a plant’s ability to make food, and may increase pollination. The quality of fruit and other high value crops can be increased due to reduced sand and soil abrasion.
• Reduced soil erosion – Windbreaks prevent wind erosion for 10 to 20 times their height downwind. They also filter wind-blown soil particles from the air.
• Energy conservation – Windbreaks can reduce winter heating costs 20 to 40% by reducing cold air infiltration into buildings. In summer, water evaporation from leaves directly cools the air.

There are also other benefits in windbreaks including a home for wildlife, visual beauty, and tree products such as firewood.

Hail netting
For open-air hydroponic growers, the case for hail netting is strong and it should be considered in any risk management assessment.

“Most netting structures we manufacture and install are able to withstand wind loads up to 147kph and greater,” said Warwick Fletcher from Ballina-based Coast Guard Netting Services.

“The higher the shade factor, the closer together the cross cable span, the higher the wind rating,” he added.

By example, Warwick points to a netting structure on a production nursery in far-north Queensland that withstood wind speeds of 240kph (150mph) when Cyclone Larry struck during the 2005-06 Southern Hemisphere tropical cyclone season. The covering had a shade factor of 40% with cross cables every 6 metres.

“Only the side walls were blown out by the cyclone,” commented Warwick.

What makes these covers work so well is the structural system. The netting uses steel cross cables over the netting, which are high tensioned to give the structure rigidity and a long life span. They call this innovative system a ‘cable span’ structure. The pole supports are buried 1 metre in the ground and the cable rods (ends) are anchored to treated logs that are buried 2 metres underground. The cross cables are tensioned to 2 tonne and have a 5.2 tonne breaking strain.

“Once the cross cables are tensioned there is no movement,” explains Warwick. “The cross cables and anchors are designed to put the poles under compression,” he added.

Warwick commented that a properly designed and installed hail net structure with side walls would have withstood the driving winds experienced by the Childers growers and prevented or minimised crop damage.

The benefits of hail netting are primarily weather-related. However, from a grower perspective, the downside is loss of colour in leafy crops and, of course, the installation cost.

Back-up systems
Back-up systems such as an emergency generator to restore power are another risk management strategy. However, power generators come at a cost that may be prohibitive for small operators.

Standby generators are either engine driven or tractor driven. Either type can be stationary or portable. Engine driven units can be either manual or automatic start. Petrol, LP gas (bottled gas) and diesel-fuel engines are available.

Generators must provide the same type of power at the same voltage and frequency as that supplied by power lines. An air-cooled engine is often used for generators up to 15 kilowatts. A liquid-cooled engine is necessary for generators larger than 15 kilowatts. Engine capacity of 2 to 21/4 hp with the proper drive system must be available for each 1,000 watts of generator output.

Automatic engine-powered, full-load systems will begin to furnish power immediately, or up to 30 seconds after power is off. Smaller and less expensive part-load systems may be enough to handle essential equipment during an emergency.

Farm insurance
Not all insurers will provide cover for tempest or flood damage, sometimes referred to as ‘Special Perils’. A ‘tempest’ is defined as a violent windstorm, frequently accompanied by rain, snow, or hail, and a ‘flood’ is defined as water from a river, creek, lake, reservoir, dam or navigable canal that overflows onto normally dry land. You can be insured for flood damage caused by a broken pipe, but not for floodwaters spilling from a waterway. Damage from a tempest or floodwaters are seldom part of basic property insurance policies, and generally have to be added separately.

Make sure infrastructure such as farm vehicles are insured. Not all insurers include farm vehicles as part of their policy.

Few insurers cover clean-up costs, unless felled trees or other storm debris lie across infrastructure that needs to be repaired or replaced. Crop loss is another area difficult to get cover. One insurer that does cover clean-up cost and crop loss is Agricola Crop Insurance, the largest insurer of agriculture crops in Australia and New Zealand. Agricola specialise in protection against damage to greenhouses and crops (on an agreed value) in the one policy. Outdoor plant and propagation nurseries may be covered as well as other buildings directly associated with the business, such as packing sheds and cool rooms.

“The policy has been designed to meet the particular needs of today’s greenhouse and nursery producers,” said Agricola’s Rebecca Walkerden, “but the greenhouse policy does not cover open-air hydroponic crop production, nor does it cover trucks and vans – only assets directly associated with a greenhouse.”

Events insured against by Agricola include storm (including hail), water damage, fire, smoke damage, lightning, explosion, malicious damage, impact and earthquake. The Agricola policy includes a standard $15,000 clean-up cost, which can be increased for a higher premium. The policy also covers business interruption, machinery breakdown, electronic equipment, burglary and money lost or stolen during transit. The Agriocola policy can be viewed or downloaded from the insurer’s website (

Generally, the insurance industry has been slow to respond to insurance claims following a spate of extreme weather events up and down the east coast of Australia over recent months, and you can bet insurance premiums will soon rise.

Agricola Crop Insurance

AON Risk Services

Building a Greenhouse

Bureau of Meterology

Guidelines for the development of controlled environment horticulture

Utah State University Extension: Windbreaks Benefits and Design