Kinetics of Hydrocarbon Induced Visual Green Color Loss on a Bermudagrass Green

Abstract

Core Ideas Kinetics models are essential to understanding complex dynamic processes.The kinetics of visual green color loss in turfgrass shoots is poorly understood.Kinetics of visual green color loss in turfgrass shoots in response to treatment with hydrocarbons was investigated.Rate and reaction order of visual green color loss in response to treatment with hydrocarbons were determined.Determining rate of and reaction order for visual green color loss increased understanding of color loss dynamics. Hydrocarbon machine fluids (MF) injure turf, inducing visual green color loss (VGCL) with onset of shoot necrosis. The dynamics of MF‐induced VGCL are unknown, having never been described. This research was conducted to increase understanding of color loss dynamics by investigating the kinetics of MF‐induced VGCL on a hybrid bermudagrass green (Cynodon dactylon [L.] Pers. var. dactylon × C. transvaalensis Burtt‐Davy). The effect six different MF had on changes in hue angle (θ) of shoots with time (t) was explained using digital image analysis (DIA) and curve fitting. Treating shoots with MF decreased mean θ from 88° at day zero to 33° at 12 d, as shoot color changed from green to brown. Fitting an exponential decay model of the form θ = θ0 + a0e‐kt to dθ/dt data revealed the rate of VGCL (−k) ranged from −4.45 d−1 (motor oil) to −0.16 d−1 (vegetable hydraulic oil) varying with MF (p < 0.01). Curve fitting also revealed dθ/dt was a first order reaction; plots of ln(θ − θ0) vs. t were linear (R2 = 1.0) for all six MF, while plots of zero order, half order, and second order reactions were not. Determining the rate of MF‐induced VGCL and its reaction order increased understanding of color loss dynamics by giving mathematical meaning to the processes. This was a step forward in understanding turfgrass injury behavior. The approach used for examining VGCL dynamics was inexpensive and nondestructive, and may be useful for other researchers studying plant color dynamics.

Color‐distance modeling improves differentiation of colors in digital images of hybrid bermudagrass

“…Image sets included a portion of one field research trial examining the kinetics of visual green color loss of ‘TifEagle’ shoots in response to treatment with petroleum hydrocarbons ( n = 56 images). This trial had been repeated in time and results were previously published (Berndt et al., 2018a). Image sets from two demonstration field trials were also evaluated.…”

“…This image set was from a field trial conducted on a TifEagle hybrid bermudagrass modified soil putting green located in North Fort Myers, FL at The Golf Club at Magnolia Landing. The original objective of this trial was to investigate the effect petroleum hydrocarbons had on kinetics of visual green color loss of individual TifEagle shoots over a period of 12 d. The results of this investigation into kinetics of color change were previously published (Berndt et al., 2018a) citing differences in rates of shoot color change due to treatment. However, differences in shoot colors between individual treatments were not reported.…”

“…Specifying color in digital images of turfgrass is straightforward (Berndt, Riger, & Riger, 2018a; Karcher & Richardson, 2013; Zhang, Pinnix, Zhang, Miller, & Rufty, 2017) but reporting of resulting color space data may be improved by differentiating colors in photographs more accurately. Having the ability to accurately differentiate colors is important because color differentiation has implications for many facets of turfgrass research involving pesticides, fertilizers, colorants, cultivars or species, and/or other areas.…”

“…Specifying color in digital images of turfgrass is straightforward (Berndt, Riger, & Riger, 2018a;Karcher & Richard-Crop Science color differences in turfgrass research (Karcher & Richardson, 2013;Zhang et al, 2017).…”

Viscosity Is Linked to Temporal Behavior of Hydrocarbon Injury on a Bermudagrass Green

“…Turf injury occurs when a machine fluid (MF) leaks onto a golf course putting green. The most pronounced symptom of MF injury on a green is a well‐defined area of necrotic shoots (Berndt et al, 2018). Differences in the behavior of the injury area (IA) with time (i.e., time to maximum IA, projected IA duration) were reported for spills of three different hydraulic fluids on a hybrid bermudagrass [ Cynodon dactylon (L.) Pers.…”