A view from the rough… greens update

Ever since I’ve been testing our greens for root parasitic nematodes post reconstruction, we only have one species called Lance nematodes. This particular root feeder is very problematic to deal with as there are no good means of control currently on the market. The link below will take you to a article published by an industry magazine and it details the difficulty in dealing with lance nematodes.

https://www.gcmonline.com/course/environment/news/lance-nematodes-turfgrass

If you don’t want to get into the weeds about nematode management, here are some of the highlights from the article…

“The three most important kinds of nematodes on warm-season turfgrasses on golf courses — the “big three” — are sting, root-knot and lance nematodes. Lance nematodes are not the most directly damaging of these three nematodes, but they are the most difficult to manage and also the most difficult to diagnose. Concern about lance nematode has been increasing among golf course superintendents, particularly as some of our newer nematicides can provide good results on the other two major kinds of nematodes, but not lance.

On turf, lance nematodes are what nematologists call “migratory endoparasites.” This means they tunnel into turf roots, tunnel around within the roots feeding as they move from cell to cell, and can tunnel back out again. Activity by these nematodes destroys root cells, disrupts root tissue and creates entry points for root pathogens.

Lance nematodes are found in the soil and within turf roots, so systemic nematicides that kill nematodes within roots would be ideal against these nematodes. This is a reason that fenamiphos (Nemacur) was so effective against a wide array of nematodes — it had both systemic and contact activity. Unfortunately, in 2021, a decade after the withdrawal of Nemacur, we do not have any true systemic turfgrass nematicides available.

The three most commonly used nematicides for nematodes on warm-season golf grasses are fluopyram (Indemnify, Bayer), abamectin (Divanem, Syngenta; Todal, Quali-Pro; Nemamectin, RightLine), and 1,3-dichloropropene (Curfew), where these can be used. Note that 1,3-dichloropropene will kill lance nematodes outside roots at the time of application, but it does not kill those inside roots and has no residual activity, so it is of limited use against lance nematodes. Abamectin kills lance nematodes it contacts, but only those outside the roots and, because of its limited movement, only in the extreme upper portion of the soil profile. While fluopyram is effective against most kinds of nematodes, lance nematodes are one of the few kinds on which this nematicide does not work. Therefore, none of our current nematicide options works well against lance nematodes.”

We have been using the abamectin product for control, but the problem with it is that it adheres to organic matter very easily, and very quickly. That is why it says in the article it only is effective in the extreme upper portion of the soil profile. Despite that bad news, there is hope on the horizon. As many of you already know, I did trial a new product that is coming to market in 2026 that is being labeled for control of lance nematodes. The product did work well. The technical rep did tell me that the product is a therapeutic treatment and not a silver bullet. So it is about establishing a management program and maintaining levels at a tolerable threshold so that the plant can endure all of the other issues. Things like shade, lake of air movement, poor quality irrigation water, high traffic, etc.

See below for the results of last week’s nematode count samples from 16 green. I tested a stressed out area and tested a lush green area, results are below. Doesn’t seem like much but good to bad is a 71% increase in nematode counts.  That’s our baseline issue…. constant nematode pressure.

The 15 years I spent at the Country Club of Naples prior to the renovation of the course, I never put a single nematicide treatment on the greens. Never needed to. So to understand to complete picture of what we are dealing with I called in the consultants we work with to develop a recovery and management strategy.

Two weeks ago I had our consulting Agronomist, Todd Lowe, stop by for a visit right after the issues presented themselves. Todd was with the USGA for nearly two decades prior to establishing his own consulting company so he’s been around and seen a lot. Last week I had Dr. Tyler Jacoby at the course to pull samples from everything (water sources, soil nutritional testing, nematode counts). I asked Dr Jacoby to do a deep dive into the scientific results of the testing, and look all the interactive relationships we are dealing with to create a total picture composite. Lastly, I have Dr. Lane Treadway from Syngenta coming in next week to go through our spray programs and chemical usage.  Dr. Treadway is the PhD leading the research and release of the new product we Beta tested for Lance nematodes control.  The goal is to look at the issue from all sides: best management practices for growing grass with Todd, Dr. Jacoby is looking at soil fertility / irrigation water quality issues and management, and Dr. Treadway will investigate our chemical strategies/applications to optimize plant health.

I feel it is important to understand ALL of the relevant issue that is affecting the putting surfaces. Once I have all the information back, and speak with all the consultants I will summarize the findings and report back to the club.