Turf Grass Rigidity is an assessment of the grass plant’s ability to resist compression from downward forces like feet, machinery and bowls. It is closely correlated with the relative turgor of the internal cells of the plant. We discussed the processes involved in keeping plants turgid here.

Turgor (and by default, Rigidity) is influenced by the chemical make up of the internal parts (cells) of the plant and particularly by the water content. Temperature and therefore growth and relative density of the turf can also influence Rigidity.

Rigidity is more accurately a measure of the turf than the individual grass plants and is closely linked to wear resistance, which varies with species and cultivar. More rigid or harder turf will be more resistant to wear.

As always, the  best way we can influence Rigidity in the turf is to keep the plants healthy through correct nutrition and water provision.

At this stage in the process of performance evaluation it must be stressed that the finer bent and fescue grasses (particularly browntop bents) will always out perform annual meadow grass in this respect and as a result we should be striving to encourage these species’.

Over fertilising and over watering will tend to cause lush and therefore soft growth and cause plants to be more susceptible to disease outbreaks. Conversely, allowing the turf to dry out too much will result in a reduction in turgor in plants and lead to a turf that is not rigid enough and susceptible to wear.

Rigidity isn’t just a “nice to have” feature; it influences other aspects of performance such as green speed and the trueness of the green.

This weekend why don’t you try to make an appraisal of the turf on your green in terms of rigidity?

At this stage it’s still going to be a personal, greenkeeper’s “feel” for how things are. Is your grass/turf dense and standing upright when you rest the palm of your hand on it? Does it feel like it will stay like that or be easily squashed flat?

Next time we will look at a feature of performance that is closely related to Rigidity.

This Series

Meantime you can review the previous articles in this series as follows:

Introduction

Part 1. The Performance Evaluation of the Bowling Green

Part 2. Turf Grass Uniformity

Part 3. Turf Grass Density

Part 4. Turf Grass Texture

Part 5. Turf Grass Growth Habit

Part 6. Turf Grass Smoothness and Colour

Part 7. Functional Turf Qualities Introduction