functioning of the plant as the leaf area available for photosynthesis is reduced. Dropping the height from 4mm to 3mm reduces leaf area by 25% and the plant functioning suffers as a result (this is more exaggerated in seedlings). The leaves produce the food source for the plant
Dropping the height from 4mm to 3mm reduces leaf area by 25% and the plant functioning suffers as a result
(carbohydrate) so, if we remove too much leaf through cutting too low for too long, the plant cannot assimilate sufficient energy to sustain healthy growth. Growth declines, rooting draws back and the plant weakens and becomes more vulnerable to environmental stress or other forms of damaging disturbance such as disease and wear. The turf thins and annual meadow-grass then takes advantage of these gaps through seed invasion. Annual meadow-grass lies in wait for thinning opportunities and then establishes in a vulnerable and weak playing surface.
Blind judgement
Constant and excessive defoliation weakens the sward over a period of time but direct damage to the crown of the grass plant can cause much more rapid
damage. One excessively low mowing operation (a scalp) is enough to damage the crown. When direct damage to the crown occurs, plants are severely damaged, cell division ceases and new leaf growth is unlikely. Such direct disturbance from extremely low mowing effectively seriously weakens or destroys the grass plant. Annual meadow-grass is usually the first coloniser into the scars created from such a treatment. The finer grasses become further away than ever.
Leave the crown alone
As turf managers we need to appreciate the sensitivity of the crown and avoid damaging it at all costs. To favour the finer grasses, keep damage to a minimum by retaining sensible mowing heights and verticutting only when absolutely necessary. The reason why regular deep verticutting is so damaging is because it
Set the mower at the optimum level rather than trying to find the lower limit
can affect the crown. Set the mower at the optimum level rather than trying to find the lower limit - it does no good. Additional protection can be afforded to the crown with regular topdressing. This will also firm the surface, support the weight of the mower and optimise the
consistency of mowing heights. Do it clean
The quality of the cut is also important. Constant mowing using ill-set, blunt or wet blades bruises, tears and grazes the grass plant. This type of damage is
Undue damage to any of the key components to growth has a massive impact on the plants ability to perform its growth strategy
draining to the system and is, therefore, a significant pressure, especially if it is inflicted day after day. Such damage to the leaf increases the disease and drought susceptibility of the turf, which are added disturbance pressures. To eliminate this pressure, keep your blades sharp and avoid contact between the bedknife and the cylinder to ensure an optimum cutting (scything) action.
Battering
Bruising damage is not restricted to blunt blades. More direct bludgeoning of the turf, and most crucially the crown, can come from slipping wheels on the triplex or the rear roller of a pedestrian mower. The most obvious form of gouging comes
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