Detecting diseases in turfgrass is an arduous and difficult task. The common name of Helminthosporium comes from the old scientific name (Helminthosporium spp). Leaf, collar and root diseases, known as Helminthosporium are nowdays, after some changes in the taxomomy, accepted to be caused by species of fungi from genera Drechslera spp, Curvularia spp, Bipolaris spp y Exserohilum spp.
|Kentucky bluegrass, bufalograss
|Kentuky bluegrass, agrostis, Poa annua, Fescues, ryegrass, bermuda grass
|Read leaf spot
|Festucas, ryegrass, Poa pratensis
|Bermuda grass, agrostis y Poa annua
The damage caused by Drechslera, can be devastating when very active and right conditions.
Source: L.B.McCarty, Golf Course Management Best Practices.
Symptomatology includes brown to purple foliar spots, black with gray centers on leaves, etc. depending on the host. In the most extreme cases the entire lawn may fade completely. Drechslera occurs predominantly on winter turf in spring and autumn.
These fungi are very active continuously, except when the soil is frozen or excessively warm. The roots, rhizomes and lower leaves are infected by the mycelium that grows from the remains of mowing and thatch, being necessary that thin layer of dew or moisture (for more than 10 hours and consecutive days), so it is necessary that microenvironment of moisture and optimum temperatures between 15 and 18 º C (although they can occur with wider intervals of Tº, between 3 and 27 º C), low light intensity (new stages of soccer much more closed) and excessive nitrogen fertilization.
The use of systemic fungicides and hormonal herbicides for broadleaf control may favor the incidence of these diseases.
These fungi produce a brown mycelium that grows inside and along the grass leaf, producing parasitic fungi and conidia that are spread to healthy leaves by wind, rain, irrigation water, mowers, etc…
Know exactly if you are suffering from Helminthosporium you have through its correct identification with qPCR analysis. Contact us at email@example.com and we will collect the necessary samples for you. Make a preventive management in order not to reach limit situations.