What is the primary threat to grass fields that destroys about 10% of them annually?

The primary threat to grass fields that destroys about 10% of them annually is indeed grubs. Grubs are the immature larvae of various beetles, and they feed on the roots of grass, which can lead to significant damage and even the death of the grass plants. When the root systems are compromised, the grass struggles to absorb water and nutrients, resulting in weakened turf and bare patches.

Focusing on how grubs specifically impact grass fields helps illustrate why they represent such a significant threat. Their feeding activity can lead to loss of aesthetic appeal and functionality of grassy areas, which is particularly detrimental in sports and recreational facilities where quality surface conditions are essential.

On the other hand, while weeds, fungi, and insects also pose threats to grass fields, none have the same direct and destructive impact on the grass root systems as grubs do on a large scale. Weeds compete for nutrients and space, fungi can cause diseases leading to patches of dead grass, and insects may cause varying degrees of distress. However, none of these typically have the same level of annual destruction percentage attributed to them compared to the damage caused by grubs.