Bermudagrass (Cynodon dactylon) Sod Rooting as Influenced by Preemergence Herbicides

Abstract

The influence of PRE herbicides on rooting characteristics of bermudagrass turfgrass was studied using sod plugs removed from the field. Greenhouse root fresh weight was reduced the greatest with dithiopyr or prodiamine. Pendimethalin caused fewer fresh weight reductions compared to dithiopyr or prodiamine and these reductions were usually for a short period. Root weight loss was due to lower root density and root malformation. Significant numbers of malformed roots were also observed for greater periods of time where dithiopyr or prodiamine had been applied.

Effect of Preemergence Herbicides on the Recovery of Bermudagrass from Spring Dead Spot

“…In 2012, bermudagrass exhibited similar recovery in response to prodiamine and oryzalin (24 and 26%, respectively), while recovery in response to dithiopyr and dimethenamid measured 33 and 34%, respectively, 14 WAT. These findings support those by Fishel and Coats (22) following applications of dithiopyr and prodiamine to common bermudagrass sod. McCullough et al (32) also observed that dithiopyr (0.56 kg/ha) significantly reduced root mass (30 to 33%) when applied to ‘TifEagle’ bermudagrass in a greenhouse setting 2 to 25 WAT.…”

“…The use of dinitroaniline (DNA) herbicides, such as prodiamine and pendimethalin, may cause abnormal swelling of turfgrass root tips (‘clubbed‐roots’), stunting of lateral root growth, and/or severely pruned roots when healthy tissue comes into contact with the chemical barrier created in the upper soil profile (21,34). Fishel and Coats (22) and McCullough et al (32) observed noticeable reductions in growth and abnormal root development in bermudagrass plants treated with pendimethalin, prodiamine, and dithiopyr. The DNA herbicide family exhibits low water solubility and readily binds to soil particles, so these chemistries tend to remain near the soil surface and do not leach through the soil profile (22).…”

Preemergence Herbicide Efficacy Under Athletic Field Traffic

“…Use of PRE herbicides on athletic fields is often discouraged as many have been shown to negatively affect bermudagrass ( Cynodon spp.) recovery following winter injury and overall root growth (2,3). Moreover, effects of traffic (e.g., losses in turf coverage) may negatively affect efficacy of these herbicides for weed control.…”

Soil Type and Rooting Depth Affect Hybrid Bermudagrass Injury with Preemergence Herbicides

“…Similar bermudagrass responses were observed with pendimethalin at 0.8 to 6.7 kg ha −1 as well. Fishel and Coats (1994) reported dithiopyr (0.56 and 1.1 kg ha −1 ) and prodiamine at 1.1 kg ha −1 reduced the total number of roots growing from bermudagrass sod but noted that reductions in root weight were less pronounced due to increases in the number of abnormal (i.e., less than 2.5 cm in length, lack of secondary root formation, root swelling) roots observed after application. In a separate study, Fishel and Coats (1993) reported substantial reductions in root weight at a 0‐ to 2.5‐cm depth with prodiamine and dithiopyr applications to ‘Tifgreen’ bermudagrass grown on sandy clay loam or very fine sandy loam soils.…”

“…Effects of mitotic‐inhibiting herbicides on bermudagrass root growth and morphology are well documented (Bhowmik and Bingham, 1990; Fishel and Coats, 1993, 1994). Given that mitotic‐ and cellulose‐biosynthesis‐inhibiting herbicides have differential effects on root morphology (Heim et al, 1998), research comparing effects of indaziflam with those elicited with mitotic‐inhibiting herbicides such as prodiamine is warranted.…”