Pythium Root Rot

PYTHIUM ROOT

Pythium spp.

Mature cool and warm season grasses

Affected turf may appear thin, off colour and slow growing.
This may occur in small patches or as a general decline and loss of large turfgrass area.
Under cool, wet conditions symptoms may first appear as small, diffuse yellow patches of turf 4 to 7 cm in diameter.
As temperatures rise, large areas of turf may wilt, turn brown and die.
In severely infected plants, crowns may appear water-soaked and root systems are greatly reduced in volume and vigour.
Roots and crown may be extensively discoloured.
No foliar mycelium is evident during infection.

Pythium Root & Crown Rot

Hot days (30 C - 35 C), humid or rainy weather when night temperatures are warm (above 20 C).
Relative humidity exceeding 90% for at least 14 hours and a minium temperature not falling below 20 C.
Pythium root and crown rot occurs in areas with high soil moisture, poor drainage and low light.
Areas with low mowing height and excessive wear.

Pythium Root is common on highly maintained turf, such as golf course and bowling greens.
Although symptoms of pythium root are typically non-distinctive, this disease can appear as yellow, irregularly shaped patches.

Found in all states of Australia.

The following products have label recommendation for Pythium root control in Australia:

Parameter	Subdue Maxx	Heritage Maxx
Mode of action	Systemic	Systemic
Optimum timing	When conditions favour disease development	When conditions favour disease development
Dose rate	1.7-3.5 l/ha	6 l/ha
Ideal water volume	600-1000 l/ha, wash in after application	600-1000 l/ha, wash in after application

Refer to label for full details.