I initiated a fertilizer trial in Amarillo, TX at the end of March this year in an area of Kentucky bluegrass managed as rough on a golf course. We are conducting the research with Anuvia Plant Nutrient’s new product, a 16-0-2-17S-3Fe multi-nutrient fertilizer with 16% organics. We are comparing the application of this product with Urea (46-0-0) alone, combined with Anuvia fertilizer, or Anuvia fertilizer alone. The combined fertilizers included 50:50 or 75:25 Anuvia:Urea ratios. Each treatment was applied at 1 or 2 lbs N/1,000 ft2 on March 31, 2015 approximately one month after the whole golf course was fertilized with 1 lb N/1,000 ft2. One set of treatments included a second application of fertilizer treatments at 1 lb N/1,000 ft2 on May 11. The primary objectives of the trial were to evaluate the effectiveness and longevity of the fertilizer to provide adequate growth, color, and quality of the turfgrass throughout the summer, but also to determine if any treatment could reduce the chlorosis of Kentucky bluegrass occurring during the hottest portion of the summer. The last month has provided some interesting observations of summer patch in and around the trial area.
About one month ago, I was collecting all the data from the trial and started noticing symptoms of summer patch in areas surrounding my research trial. The affected areas were irregularly shaped, generally small diameter, and sunken patches of necrotic turf. Those small symptomatic areas coalesced and became much larger in the two weeks following the initial sighting (Image 1). Additionally, the symptoms were present in my fertilizer trial as well. I rated each of the plots for the percent area that was exhibiting the symptoms of summer patch to determine if any of the treatments were reducing severity. Unfortunately, there were not statistical differences in the treatments; however, the plots that were treated with urea only in March and May did have numerically more area exhibiting symptoms compared to all other treatments. The urea only treatments had a mean of 27.5% plot area showing symptoms of summer patch (Image 2). The closest treatment to this only had 12.5% of plot area with summer patch symptoms. The other treatments containing ratios of Anuvia and urea or Anuvia alone ranged from 2 to 12.5% of plot area with symptoms with the untreated control only having 3.75% summer patch symptoms. I will be going back to rate the trial in Amarillo this week, so I am excited to see if the symptoms have expanded and spread more in the last two weeks to potentially provide statistical differences among fertilizer sources or rates.