The cause of these spots may surprise you

Have you ever seen patches like this on Zoysia turf? Maybe the early stages of an intense large patch outbreak, or elephant’s footprint (Rhizoctonia cerealis) that got out of control? Way out of control?

MLSN and disease

This post was first published at the TurfDiseases page and I am reprinting it here. If you want to have a good sward, then you’ll need to make sure the grass is supplied with enough nutrients.

Rolling, nitrogen, dollar spot, and Microdochium patch

There’s an interesting article by Espevig et al. on Effects of rolling and N-fertilization on dollar spot and Microdochium patch on golf greens in Scandinavia. rolling a red fescue green two times a week reduced dollar spot by 61% compared to no rolling rolling four times a week reduced dollar spot by 95% increasing annual N on a creeping bentgrass + Poa annua green from 15 to 24 g/m2 reduced dollar spot by 24% but the following spring saw twice as much Microdochium patch on the plots which received the higher N rate There are a number of surface performance benefits that come from rolling, and disease suppression is one of them.

Recording of my presentation about managing turfgrass diseases in Asia

The recording of my presentation on “Managing turfgrass diseases in Asia with minimal input” is now online. Watch it here. I gave this presentation as part of the session on “Precision Turf and Ornamental Disease Management in the 21st Century” at the International Congress of Plant Pathology in July.

Managing turfgrass diseases in Asia with minimal input

These are my slides for today’s presentation in the “Precision Turf and Ornamental Disease Management in the 21st Century” session at the International Congress of Plant Pathology in Boston. The abstract for my presentation is here.

Smith-Kerns and korai

Yesterday I saw some dollar spot on a korai (Zoysia matrella) fairway in Kyushu, Japan. I wondered what the Smith-Kerns model probability for dollar spot had been. So I looked up the recent temperature and humidity at a nearby weather station.

The probability of a dollar spot epidemic

I’ve written about reactive greenkeeping being at least a viable option, and have implied that it is preferable to proactive greenkeeping. With a little effort, one can get information (data) about the weather, the amount of water in the soil, the quantity of nutrients in the soil and the quantity of nutrients used by the grass, the growth rate of the grass, and so on.

So much silicon research I can't keep up with it all

I was searching the Turfgrass Information File for ‘turfgrass quality rating’ and a couple interesting silicon/silica/silicate projects appeared in the results. The first one, Fortification of Potassium Silicate With Compost Tea and Seaweed Extract for the Management of Dollar Spot of Turfgrass by Manoharan, I’ll summarize with this quote: “this study did not effectively control the dollar spot disease severity.

"Potassium applications have been associated with increased winter diseases in northern climates"

Who would have thought that adding potassium would increase disease? I enjoyed talking with Doug Soldat about this research when he presented “Potassium fertilization affects microdochium patch severity on creeping bentgrass” by Bier et al.

N & MLSN: what's the connection?

We’ll get to the N below. But wow! I didn’t know silica was such a hot topic! After writing a few days ago (original post here) about silica and green speed, and how it doesn’t make sense to me that silica application could increase green speed, there was quite a response — by e-mail, at this wild discussion on Facebook, and on Twitter.