Friday, October 30, 2009

Rotten Falling Palms

Hygiene, hygiene, hygiene - but only after palms die. If you have unexplained falling, rotting palms, then one of these two diseases may be involved.

They occur in the NT, as well as many tropical regions around the world.

Ganoderma Butt Rot of Palms
· Ganoderma butt rot is caused by the fungus Ganoderma zonatum. This fungus degrades or rots the lower 1-1.5m of the trunk.
· All palms are considered hosts of this fungus. This fungus is not a primary pathogen of any other plant species.
· Symptoms may include wilting (mild to severe) or a general decline.

The disease is confirmed by observing the basidiocarp (conk) on the trunk. This is a hard, shelf-like structure that will be attached to the lower 1 - 1.5m of the palm trunk. However, not all diseased palms produce conks prior to death.
· A palm cannot be diagnosed with Ganoderma butt rot until the basidiocarp (conk) forms on the trunk, or the internal rotting of the trunk is observed after the palm is cut down.
· The fungus is spread by spores, which are produced and released from the basidiocarp (conk) [seen upside down in the left photo].
· Conditions that are conducive for disease development are unknown.
· There are currently no cultural or chemical controls for preventing the disease or for curing the disease once the palm is infected.
· A palm should be removed as soon as possible after the conks appear on the trunk. Remove as much of the stump and root system as possible when the palm is removed.
· Because the fungus survives in the soil, do not plant another palm back in that same location.

Thielaviopsis Trunk Rot of Palm
· Thielaviopsis trunk rot is caused by the fungus Thielaviopsis paradoxa.
· Due to this disease, the palm trunk either collapses on itself or the canopy suddenly falls off the trunk, both without warning. The palm canopy often appears healthy prior to collapse.
· Except for “stem bleeding,” which is common in coconut and some single stem palms, there may be no symptoms prior to collapse of the palm.
· Only fresh trunk wounds will become infected by the fungus, so disease management includes limiting man-made wounds to the palm trunk, especially the upper third of the trunk.
· If the disease is detected early, cutting out the rotted, infested wood followed by spraying the wound site with a fungicide may be useful.
· There are no other methods to prevent or cure this disease. The palm should be removed immediately, and the diseased trunk portion destroyed but not recycled.

Thielaviopsis paradoxa is a fungus that can infect any part of a palm, and so can cause numerous diseases. In Florida, the two most frequent (and usually lethal) Thielaviopsis diseases observed in the landscape and field nursery are a bud (heart) rot and trunk rot.

Unfortunately, there often are no visible indications that a palm has Thielaviopsis trunk rot until either the trunk collapses on itself or the canopy suddenly falls off the trunk. The canopy often appears normal and healthy.

Thus, there are no symptoms that can be used to predict which palms are infected and which ones are not. In most cases, the trunk rot is occurring in the upper half of the trunk. This may occur because the number of lignified fibers are greatest in the lower trunk and least in the upper trunk. As indicated previously, this fungus prefers to rot non-lignified or lightly lignified plant tissue. “Stem bleeding” is a common symptom of Thielaviopsis trunk rot observed on single stem palms eg coconut, royal palms. This stem bleeding is a reddish-brown stain that runs down the trunk from the point of infection.

Thielaviopsis trunk rot usually occurs quite randomly, with only a few palms in the landscape being affected. However, there are situations where high numbers of palms in a single landscape can become diseased, for reasons that are not always clear. In all situations, there has to be a fresh wound to the palm. Wounds can occur naturally, such as trunk cracks due to excess water uptake. Insects (such as beetles), birds (sapsuckers pounding on the trunk), rats, and other mammals can cause wounds. Blowing objects during a wind storm can strike a trunk and cause a fresh wound.

Humans cause wounds with nails and climbing spikes, or during the digging and transplanting process.

Humans also create wounds when trimming leaves that are not yet dead. Leaf petioles are cut as close as possible to the trunk. If a leaf petiole has any green color associated with it, the leaf is still living. When that still living petiole is cut, a fresh wound is created that may be infected by the fungus. Trunks can be easily wounded during the trimming process with the careless use of the pruning tool. Pulling a leaf off the trunk, when the leaf petiole still has green tissue, can create a fresh wound.

The fungal pathogen can spread from palm to palm as follows. First, if spores are produced on diseased palm tissue, these spores can be moved by wind and water to fresh wounds. The spores may also be moved about by insects or rodents. Second, the spores that can survive in the environment, especially soil, for long periods. Fresh wounds could become infected via contaminated soil.

Except for the stem bleeding, there are often no outwardly visible symptoms that indicate which palm in the landscape or field nursery has Thielaviopsis trunk rot. Thus, there are no proven strategies for preventing this disease. Once the palm has collapsed, remove it immediately as it is a source of fungal spores.

If one does observe the initial stages of the trunk rot, such as the stem bleeding, it would be useful to cut out the area of rotted wood (if it is not too large a trunk area) and spray the wound thoroughly with a fungicide labeled for Thielaviopsis diseases. Examples include, but are not limited to, products with the active ingredients thiophanate methyl or fludioxonil. The goal is to prevent the fungus from infecting the fresh wound made when you cut out the infested, rotted wood. All tools used to remove the rotted wood must be cleaned with a disinfectant. [Banrot is a possible trade name]

Examples of disinfectants include: 1) 25% chlorine bleach (3 parts water and 1 part bleach); 2) 25% pine oil cleaner (3 parts water and 1 part pine oil cleaner); 3) 50% rubbing alcohol (70% isopropyl; equal parts alcohol and water); 4) 50% denatured ethanol (95%; equal parts alcohol and water); 5) 5% quatenary ammonium salts. Soak tools for 10 minutes and rinse in clean water. For chain saws, soak chain and bar separately.

Diseased trunk material should be destroyed and should not be recycled in the landscape. Chipping and then spreading the infested material in the landscape could spread the fungus to healthy palms. If the trunk is chipped, it should be placed in a properly constructed and monitored compost heap, or taken to a landfill or incinerator.

[partially sourced from extension articles - Monica Elliott et al, Uni of Florida; all photos from Darwin]

Wednesday, October 28, 2009

Compadre Zoysia at the Darwin Waterfront Precinct - Brilliant!!

Darwin Waterfront Precinct

Major projects are inevitably fraught with complexities, time delays and both minor and major problems. Where these involve landscaping, tempers usually get very short……… almost always, with the landscaping being among the last major activities, it gets time challenged, cost challenged and yet……….it has to be ready on time, and look fantastic.

Compadre zoysia was chosen as the grass of choice for the Waterfront project and because it was to be sown by seed, that challenge was even more complicated, as around 12 – 20 weeks were needed after sowing, to have it visitor ready at the opening. Many smaller areas were able to be sown much earlier, and have been grown relatively easily, but much of the main area in front of the hotels was always going to be near the very end, and initially suffered because of that delay that then ran into the weather problems.

There most certainly have been a few challenges along the way, and although we had factored into the scenario a local supply of some Compadre zoysia turf to meet those final last minute problems, the seed sowing also had a few of its own problems, caused by late sowing and very heavy monsoon rain soon after sowing. Weeds were an issue, with the area here, initally weedy with sedges, being managed, and converted into the area in the first photo below.

However, this and other issues were successfully managed, and fixed and the Compadre has thrived on the whole area.

The photos below were taken late October 2009, about 9 months after sowing. It looks fabulous……….soft to walk on, non itchy, reduced mowing frequency ………all it was chosen for initially.

Lush grass......

Great vista across the Compadre turf

Compadre zoysia is tolerant of wear around seats and high activity areas

It really offers a smart, water efficient, low maintenance, wear tolerant, low fertiliser requirement and atractive turf for domestic and commercial areas, including parks and ovals in the north of Australia.........and can be established at low cost.

Monday, October 26, 2009

Emissions Trading 101 - Cap and Trade

The whole issue of an ETS seems to be inherently complex.

Recently I was able to access the article by Joel Kurtzman of the Milken Institute in the USA, which was subsequently published in Foreign Affairs in September 2009. It is available on the Institute web site and was also published in the Review section of the Australian Financial Review on Friday 16 October 2009.

He discusses the free market aspects of the Emissions Trading Scheme [ ETS] in a rational, coherent and clear manner. It is worth reading for the clarity.

A really good explanation of the broad scheme. While many will disagree with some issues, it clearly explains the principles and operations of the managed markets.

It might just work!

Wednesday, October 14, 2009

Ireland To Be GM Free

As part of a politically expedient deal, the Irish Parliamentary political parties have agreed on a deal that will make Ireland free of GM crops, and presumably food from those crops, through a voluntary label scheme. It is planned to have this extend to the whole of the island of Ireland ie Northern Ireland as well, if a deal can be done. It is presumed this will also extend to animal and animal products.

The organic consumers have a long media release available which does provide a lot of detail on the process and the deal itself.

Read about it here:

Tuesday, October 13, 2009

The REAL GM Food Scandal

For a salutary examination of the issues around GM food have a look at the following:

This appeared in Prospect Magazine in November 2007.

The noises have increased but really.............lets get back to basics! If agriculture is to feed the world between now and 2050, we need to invest in technology, develop a whole lot of smarts about land management and crop production and produce food. While there will be changes in how and where food wil be produced and the logistics of moving food to where required, but food will definitely be needed.

Western Europe is dominated politically by left leaning greenies, hence the anti GM stance. But recent figures quoted in Scientific American November 2009 show the big use of GM crops are in the US, Argentina, Brazil, India and often by smaller scale farmers.

They are not always chosen because the multinationals dominate the seed industry.......rather they are chosen because they perform, make money for the growers and save labour and costs.

Thursday, October 08, 2009

Soil Carbon May Come from the Tractor Exhaust

A Canadian inventor may have found a very useful tool that can inject tractor exhaust gases into the soil and help build soil carbon and stimulate soil microbes.

Yes.......there are many snake oil salesmen around, but this does sound possible. It fits well with some recent agronomic evidence that if small doses of nitrogen are applied to agronomic systems they may act first on microbial populations that are able to then grow and act on soil minerals and organic systems that have stored nutrients, to help release N and P in the soil in a form that can be taken up by plants, rather than directly on the plants themsleves. is still relatively early days, but there are some serious scientists giving it a tick already.

Read about it yourself............and think.
When the smoke from a tractor exhaust goes up, that’s pollution. But get those emissions down into the soil and they become fertiliser, as Canadian farmer, Gary Lewis, is demonstrating.

Mr Lewis has spent the best part of a decade developing and refining a system that pipes tractor exhaust emissions through a condenser and into the pneumatic system of air seeders, which then injects the carbon and nitrogen-rich emissions into the ground with the seed.

What is generally considered as pollution is in fact prime soil food, Mr Lewis said, and tractor exhaust has allowed him and other farmers working with his technology to grow excellent crops without using conventional fertilisers. The exhaust gases are believed to stimulate microbial activity and root growth, allowing the plants to more efficiently extract nutrient and moisture from the soil.

The United Nations has shown an interest in the system, which might not only reduce fertiliser dependency but cut greenhouse gas emissions.

Mr Lewis, an Alberta rancher and former auto mechanic who specialises in growing timothy hay for export, claims not to have used fertiliser on his 250-hectare irrigation farm for at least six years, instead fertilising it with his “BioAgtive” technology. Mr Lewis said he had seen no loss of production, his soils had moved from pH 8.0 (the same as the irrigation water) to a pH of about 7.0, and soil organic matter levels were now at about 10 per cent.

In testimonials quoted on the BioAgtive website, former Agriculture Canada scientists turned consultants, Dr Jill Clapperton and Dr Loraine Bailey, agree that something positive is happening in BioAgtive treated soils. “The obvious conclusion is that the exhaust had a positive effect on crop growth, yield and quality, and may have positively enhanced soil nutrients and nutrient chemistry,” Dr Bailey writes.

Meanwhile, Dr Clapperton is working on a scientific paper outlining how the technology works.

Understanding why BioAgtive is not just “blowing smoke”, as Mr Lewis feels many scientists think he’s doing, requires a different perspective on exhaust emissions.

Surprisingly, a breakdown of the content of diesel exhaust looks like a partial Christmas shopping list for plants. A Volkswagen analysis of light-duty diesel engine exhaust published in a World Health Organisation-sponsored report gave an analysis by weight of 75 per cent nitrogen, 15pc oxygen, seven per cent carbon dioxide and 2.6pc water vapour. Several other substances existed in quantities of less than 0.1pc.

Mr Lewis calculates a zero-till rig will put 1100 kilograms of air through the tractor engine to work a hectare.

Dr Bailey writes that the exhaust treatment “resulted in significant release of soil N and/or stimulated the crops to take up soil N”. She said there were also small increases in the uptake of phosphorus, potassium and sulphur and slight shifts in the amount of some micro-nutrients taken up by the crops.
If it proves viable, BioAgtive will also be a tool for farmers wanting to reduce their profile under emissions trading.

The system relies on attraction between negatively-charged ions in the gases and the soil’s positively charged alkaline component to hold the gases in the soil, as well as sealing it in.

Some Canadian farmers are now growing their own biofuel crops using BioAgtive technology, Mr Lewis said About 150 farmers around the world, including in Australia and recently China, had bought into the concept.

While the system doesn’t come cheap, at about $C40,000, Mr Lewis points to what he says is the potential to save hundreds of thousands of dollars in fertiliser in a year.

Gary Lewis is booked to talk at the Carbon Farming Conference and Expo at Orange, later this year on November 4-5.

[ partially sourced Qld Country Life]