Custom Search

Large Patch Resistance of Zoysia?

Last year I suggested that there are differences in large patch susceptibility between Zoysia japonica and Zoysia matrella. A photo of large patch posted last month on the Turf Diseases Facebook page by Dr. Mike Richardson and follow up comments by Dr. Richardson and Dr. Kennelly on the relative lack of resistance they have observed has prompted me to write on this subject again, for all of my observations lead me to believe that there are differences in susceptibility to large patch among zoysia varieties and between zoysia species. Click on the thumbnail images to see photos of large patch on zoysia in Asia, and you will see that the symptoms are most evident on Zoysia japonica:

large patch on Zoysia japonica large_patch_noshiba_kanagawalarge_patch_noshiba_west_japan large patch on zoysia at Shimane, West Japan

Why am I convinced that there is some resistance to this disease?
  • I've noticed that when Zoysia japonica and Zoysia matrella are growing in the same general vicinity, large patch may be present on Zoysia japonica but not on the Zoysia matrella.
  • Research at the Chiba Prefectural Agricultural Experiment Station in Japan has found that there are differences in resistance to large patch among zoysia varieties.
  • Dr. Larry Stowell suggested there may be a mowing height effect on the disease where higher cut turf might be more susceptible but a greenkeeper at Japan assures me that at his course it is the Zoysia japonica at fairway height that gets more disease than the higher mown rough.
  • Masahiro Kato has published on large patch resistance in zoysia and he found that the differences in resistance among varieties are related to differences in leaf sheath lamination structure.

One response to “Large Patch Resistance of Zoysia?”

Mike Richardson said...

Thanks for the post Micah. Maybe we are just not speaking the same language here (since I am not a trained pathologist, that is HIGHLY likely). When I said there are no resistant cultivars, I meant that I have never seen a cultivar that would not show any symptons (maybe I am thinking immunity?). We have definitely seen variation in disease response between cultivars, with matrella cultivars seeming to be more tolerant of the disease than japonica. However, once those tolerant cultivars get on a golf course, it seems to be just a matter of time before the patches start showing up.

Related Posts with Thumbnails