I'll retire to my usual haunt to ponder this one. Let me set the scene.

Mid-July, Saitama prefecture, Japanese lawngrass (Zoysia japonica) at the back of a driving range, infrequent mowing, no recent drought, and no recent frosts. Looking down at the grass – for one must be observant – I saw horizontal bleaching or striping on the leaves.

"Aha," I said, "I've seen this before. At Okayama prefecture on the same grass species, in the same season. And I've seen this picture with almost identical symptoms on the same species grown in Florida."

Bleached bands on Zoysia japonica near Tokyo

I inquired about recent weather and drought and herbicide applications. Temperatures have been relatively mild. There has been enough rainfall to keep the grass from experiencing drought stress. The hottest day of the year so far was 1 June, with a temperature of 34°C. That was more than 6 weeks ago, and since then the temperatures have been mild.

Bleached band in the center of a Zoysia japonica leaf near Tokyo

Glyphosate was applied about a month ago, not to this grass directly, but in an immediately adjacent area less than 1 meter away.

Have you seen these symptoms on Zoysia japonica? If so, under what conditions do they appear?

Bleached bands on Zoysia japonica at Okayama