Nematode problem?

David Batesin Consultancy

Nechells-Sept-06-(48).jpgIs there a reason why nematodes are increasing and, therefore, our pitches are under the continual threat of infection and damage?

The lack of appearance, wear and tear and health are all becoming more evident on pitches generally and, in an attempt to offset this, more and more nutrient inputs are regularly being applied by Turf Managers in an attempt to right the problems.

David H. Bates suggests it may simply be a nematode problem?

Nematodes are any unsegmented worm and are frequently referred to as round worm. They are one of the most common and destructive of all the parasites found on plant roots throughout the world. Many nematodes are pathogenic, inducing disease within the environment in which they live and multiply. They drain off the growth and energy of the host plant.

Research has shown that over 15,000 different species exist worldwide, accounting for over 12% of losses within the world's valuable crops per year. It is a problem not to be over looked. However, it is further recorded that from these 15,000 species, only 2,200 are plant parasites and perhaps as few as ten species attack our commercial crops.

The issue here is this: root and rhizosphere exudates and the variations of carbon dioxide available play an important role in attracting or repelling nematodes. According to Webster and Kross, basic health, stamina and balance afforded by humic and fulvic acids and non pathogenic micro organisms ward off nematodes.

There is a choice of ways to attack this particular energy draining and damaging problem of nematodes.

1. To purposefully set out to control the nematodes.

2. To aim for genetic plant control.

Humic substances can positively affect plant generics to activate more nematode repelling compounds. In turf culture, this results in greater plant productivity with a stronger, healthier sward along with balanced natural nutrient inputs.

If the plants are healthy and strong they resist nematode infection and are not penetrated as readily as susceptible plants.

Basically, the mechanical resistance of the tissue tends to play a role in the plant's ability to defend itself against nematodes. By stimulating and developing stronger, more fibrous roots utilising new age nutrition and associated with humic acids, the walls of the cells become less penetrable by nematodes.

Cytokinin, like responses provided by humic and fulvic acids and micro organisms such as Cyanobacteria, is directly involved in the production of thickening plant walls.

Once the nematode enters the plant, that plant may produce protective compounds that are toxic to nematodes, including phenolics.

However, according to Huans, the healthy plant has another alternative. The plant may shutdown the supply of certain nutrients to the nematodes and thus starve them out of the infected root.

Nutrition may help to affect the sex ratio of the parasite. For example, by withholding enzymes from the young nematodes their sex ratio becomes heavily weighted towards males, this results in less root damage because there are fewer productive egg laying females.

Pitches and greens constructed predominantly of sand or having had the organic content removed, mechanically or otherwise, may incur more of a nematode problem than in the past.

Studies address the importance of both humic and fulvic materials for the production of the plant. Such application of high quality humic and fulvic acids bring about positive benefits to the production of the plant. When you strip out using chemicals or mechanical operations you may well assist in nematode infestation. Losing humic and fulvic acids only increases the potential problem.

Pathogenic nematodes are not as severe in soil enriched with organic materials as in soils where the extracted organic matter has been removed, hence resulting in low humic content.

Humates naturally develop various compounds that interfere with the operation of nematodes' nervous system. A narcotic effect is produced as the amphids and phosmids of the nematodes are prohibited from sending messages. In this manner the nematodes become paralysed and die.

Concepts of Nematodes Management

1. Increase the soil humic and fulvic content. This naturally helps control parasitic anomalies, particularly on sand constructed facilities or where the extracted top surface has been fraised off. Not only do nematodes become evident, but other common fungi and disease pathogens such as Fusarium also confirm this.

2. Encourage proper soil condition to assist in the efficient aspiration of the oxygen-ethylene cycle.

3. Discourage nematode activity through the less rapid release of nitrates from oxidising organic matter which also assists the operation of oxygen-ethylene cycle.

4. Allow for an overall increase in organic matter and mineral content in the soil and avoid over use of heavy machinery and pesticides, always aiming at an efficient operation of the oxygen-ethylene cycle and lessening compaction of the soil.

Research performed by Norton and Decker confirms that enhanced plant nutrition is a most effective method of overcoming nematode infestation.

Less nitrogen (N) is required when nematodes are suppressed, along with the stimulation of mycorrhigae, a form of root fungi.

Granular salt fertilisers stimulate unnecessary cell elongation, which is usually experienced between seven to ten days following application, thereby weakening the plant's resistance to nematodes, disease and other stresses often observed. It is so important for the Turf Manager to carefully select and purchase nutrients wisely.

Today's research indicates that Amine Nitrogen (N) provides a better control, with substantial growth, health and root development from which resistance to pathogens and other stress related challenges are managed. Nitrogen in the form of NH2 provides ready to use nutrition, balanced with keylate iron, calcium and magnesium. The strengthening of the cells provides immunity while satisfying a sustainable and healthy plant system capable of resistance.

Please note that humic and fulvic acid substances are involved in energising the plant to produce these reactions in a natural manner as a define mechanism.

I trust you find my comments helpful and constructive and may at least provoke you to act now rather than wait for the problem to strike you!!!

About the author: David H. Bates has over thirty years experience within the Sports and Amenity Industry and has developed a proven knowledge and understanding of humic, fulvic and plant therapy systems of nutrition. David H Bates Agronomy Service Ltd.


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