StubbyRoot Nematode Paratrichodorus spp

The stubby root nematode has been on the increase as the main species causing damage in the eastern states of Australia. Threshold numbers of this species is based on >80 in 200mls of soil when using the White Head tray extraction method. The stubby root nematode is found in numerous parts of the world and are external feeders (ectoparasitic) at the tips and sides of young succulent roots. It has been recorded that at least five species of Paratrichodorus transmit plant viruses

Key A Swollen Condtion of Cuticle B Non Swollen cuticle a Curved stylet

 

Nematodes Damaging Turf

There is a complex of nematodes damaging turf in Australia but the damage thresholds for these are not yet well defined. Factors such as grass species, mowing height, nutritional status, soil compaction, soil type and presence of other root pathogens all influence the extent of damage by nematodes (Stirling et al. 1999). Like most plant parasitic nematodes those infesting turf use a stylet or spear at their head end, rather like a hypodermic syringe, to pierce plant cells and then suck out fluids from within. The most important nematodes in turf (information kindly supplied by Turgrass Technology) are:

Plant Parasitic Nematode		Threshold for damage
Common name	Genus name	1200 ml soil
Root Knot	Meloidogyne	100
Root Lesion	Pratylenchus	100
Stubby Root	Paratrichodorus	80
Dagger	Xiphinema	60
Spiral	Spiral	600
Rotylenchus
Tylenchus
Pin	Paratylenchus	200
Ring	Criconemella	200
Sheath	Hemicycliophora	160
Stunt	Tylenchorhynchus	200
Sting	Ipibora	20
Awl	Dolichodorus	20
Lance	Hoplolaimus	80
Needle	Longidorus	40
Cyst (larvae)	Heterodera	150

Table of General Threshold Damage levels for Turf

Plant parasitic nematodes were associated with sports turf damage in Australia in the late 1960's and early 1970's.

Nematodes vary in size ranging from 0.08-2.0mm in length. The sting nematode (Belonolaimus spp) is a large nematode and cause severe damage to turfgrass in relatively low numbers compared to other species.