Turf Disease Detection VI. Anthracnosis

Anthracnosis is a fungal disease caused by the fungus Colletotrichum Cereale, which survives on remains of soil organic matter. The most important damages take place on Poa Annua greens and sometimes on Agrostis greens.

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Turf Disease Detection V. HELMINTHOSPORIUM COMPLEX. Drecheslera spp.

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.

DiseasePathogenHost
Melting outDrecheslera poaeKentucky bluegrass, bufalograss
HelminthosporiumBipolaris sorokinianaKentuky bluegrass, agrostis, Poa annua, Fescues, ryegrass, bermuda grass
Read leaf spotDrechslera erythrospilaAgrostis
Helminthosporium blightDrechslera dictyoidesFestucas, ryegrass, Poa pratensis
Zonate eyespotDrechesleraBermuda 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.

Rhizome rot of Poa pratensis infected by Drechslera poae (Courtesy of W. Smiley)

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.

Melting-out de Poa pratensis infectado por Drechslera poae (Cortesia de P.H. Dernoeden)
Red leaf spot on Agrostis stolonifera, caused by Drecxlera erythrospila (Courtesy P.J. Landschoot)

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…

Do you have similar symptoms? Get out of doubt by writing to info@tiloom.com and we will send your samples for analysis via qPCR or do it yourself through our PhytFieldLab.

Know exactly if you are suffering from Helminthosporium you have through its correct identification with qPCR analysis. Contact us at info@tiloom.com and we will collect the necessary samples for you. Make a preventive management in order not to reach limit situations.

Turf Disease Detection IV. Pythium

Members of the genus Pythium belong to a group of organisms known as “oomycetes”, a group of filamentous protists belonging to the pseudofungi group, which survive year after year as oospores on our greens or soccer fields, and are also very mobile through the movement of irrigation water, our mowers or the players themselves.

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