LAWN: What flows through your spreader this time of year?


Update (05/26/2017)

Anthracnose Ante Raised

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MU Turfgrass & Landscape Field Day - August 1

Plans are underway for the 2017 Mizzou Turfgrass & Landscape Field Day.  The event will be held August 1 at our research facility at South Farms.  A few topics of discussion will be:

  • An update on Emerald Ash Borer and other invasive insects
  • Soil Health: What is it and how can it be applied to maximize plant health?
  • Turfgrass nematodes: New tools and how do I know if I need them?

Registration for exhibitors can be found at the site -, and attendee registration will be available shortly.  For more information, feel free to contact me at or Kevin Dern at


May Temps Normal, Rainfall Above

  1. All told, May temperatures should run just about on average. - Source: Pat Guinan
  2. Missouri has been hit with considerable rainfall in the past 10 days. - Source: MRCC

In a break from the pattern, May temperatures should end up right about on average. This would buck the trend of 2017, in which every month has been at least at least 3 (April) and as much as 11+ degrees (February) above average in Missouri. This recent cool spell has driven down soil temperatures into the middle and upper 50s in the region, which is a considerable anomaly for late May. Soils are cool and also saturated, as considerable rain has occurred in much of the state over the past 7-10 days. May precipitation totals look to be an inch or more above average, and May is typically our wettest month in Missouri.

The cool weather looks to stick around into next week, with highs only in the upper 70s and lower 80s.  We are also forecasted to dry down a bit next week, and at least get back to normal rates of precipitation for the first portion of June. These conditions should keep the threat of large patch on zoysiagrass in the foreground, but hopefully will also let more cool season growth occur before the travails of summer arrive.

Temperatures were approximately 4” degrees above normal in April, but have stayed fairly close to average to start May. This pattern looks to change in late May, with above average temperatures expected for the region in the 10 – 14 day NOAA outlook (see below). Unfortunately, the region doesn’t look to dry out either.  May is typically our wettest month, with over 4.5” of rainfall expected.  The Kansas City area has dried out, but St. Louis, Columbia, and Springfield have all received 2-3” of rainfall already this month. With this accumulated and forecasted rainfall, we may also expect a wetter than normal May to go along with our still soaked drawers from April. 

Cool End of May/Start of June Expected

  1. Next week expected to remain mild for late May/early June. - Source: NOAA CPS
  2. After the weekend’s event, rain is not expected to be heavy next week. - Source: NOAA CPS

Quick Hits

Early symptoms & signs of Pythium infection

  1. Purplish mottling of the stand can be an initial symptom of root infection.
  2. Oospores found in roots.

Not surprisingly, we are observing more Pythium root rot infection on creeping bentgrass putting greens. In a sample from the St. Louis area, purplish mottling symptoms were also observed throughout the stand. Roots within the sample were long and for the most part appeared healthy. In several, however, considerable infection was noticed along with numerous oospores. In this case, the superintendent had applied preventives in the form of Insignia and Segway but may not have applied enough post-application irrigation to carry the material throughout the depths of the 4” + root zone. This last bastion of spring is also the last morsel of opportunity to put down bentgrass roots. Make sure that protective fungicides (which only move up in the plant) are watered in effectively to protect roots, and conduct an irrigation audit (rain gauge or catch can) to assess how much water is being applied to drive the fungicide down. Also with all this rain, starting a regular venting schedule now by punching holes with pencil, bayonet, needle, etc. tines will pay dividends this summer.       

They’re back.  Three Japanese beetle adults were caught in traps last week in the Columbia area. This early arrival is approximately two weeks earlier than previous years. Whether spraying any pesticides to protect Lindens, roses, or turfgrass please be mindful of beneficial pollinator species. Dr. Doug Richmond from Purdue University has accumulated a series of pollinator protection publications that deserve your time and attention. Click this link to go to his resource.

Low N Rates Up Anthracnose Ante

Basal Rot Anthracnose in Kentucky

  1. A severe anthracnose outbreak was observed on 'Penncross' bentgrass this week.
  2. Jet black crowns, stolons, and roots are a sure sign of this disease.

Although our weather systems normally travel from west to east, the east and south are often our first indicators of impending disease issues in Missouri.  Although often thought of a Midwestern state, Missouri and its climate is probably better associated with other “tweener” transition zone states such as Kentucky, Tennessee, northern Arkansas, and southern Ohio. Last week, we received a sample from Kentucky with significant basal rot anthracnose symptoms on ‘Penncross’ creeping bentgrass.  For those with a history of this disease or with susceptible bentgrass cultivars (such as ‘SR1020’, ‘Pennlinks’, ‘Princeville’, etc) in this region, this report should sound the alarm bells as conditions are also ripe for occurrence here.

Dr. Joe Rimelspach and Todd Hicks from The Ohio State University recently posted an anthracnose warning on their channel and I echo their message.  In addition, Rutgers University led by Drs. Bruce Clarke and Jim Murphy have developed a great resource in an extensive list of BMPs for managing this disease.

One unique aspect about the potential for outbreaks this spring may rest with nitrogen.  Anthracnose is a low N disease, and will cause more severe damage on nitrogen-starved plants. The cool, perfect cool-season growing weather in mid-May has sparked the need for more nitrogen use by charged up bentgrass. Heavier granular applications of 0.5 lb N/1000 sq ft or more made in early April are probably gone now from all of the torrential rains and warmer earlier spring temperatures. If currently initiated, an extremely light spoon feeding regimen may not be enough to maintain growth, and may predispose susceptible bentgrass cultivars to anthracnose. This “tweener” time of bentgrass N need and low rates from a summer spoonfeeding program also occurs in August or September when temperatures drop off rapidly. 

If growing a susceptible cultivar consider bumping up the nitrogen rate slightly (an extra 0.05 or 0.1 lb N/1000 sq ft) to accommodate the current conditions, and then back off again when summer heat hits. As noted in the Rutgers BMPs, light, consistent topdressing aids in managing basal rot anthracnose by protecting the crowns and will also regulate any surge in foliar growth.  Lastly, basal rot anthracnose obviously strikes at the base of the plant. Therefore, apply fungicides targeted for this disease in a good amount of water carrier. A minimum of two gallons/1000 sq ft of water carrier is advised, but three wouldn’t hurt.    


Lee Miller
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Extension Turfgrass Pathologist
University of Missouri