Sod Regrowth of St. Augustinegrass after Preemergence Herbicide Application

Abstract

St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] sod production involves stolon regeneration from strips left from the previous harvest. Field studies were conducted to evaluate stolon regrowth and rooting following preemergence application of herbicides. Herbicides evaluated were atrazine [6‐chloro‐N‐ethyl‐N'‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine], dithiopyr [S,S‐dimethyl 2‐(difluoromethyl)‐4‐(2‐methylpropyl)‐6‐(trifluoromethyl)‐3,5‐pyrldinecarbothioate], isoxaben [N‐[3‐(1‐ethyl‐l‐methylpropyl)‐5‐isoxazolyl]‐2,6‐dimethoxybenzamide], metolachlor [2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐1‐methylethyl) acetarnlde], oxadiazon [3‐[2,4‐dichloro‐5‐(1‐methylethoxy)phenyl]‐5‐(1,1‐dimethylethyl)‐1,3,4‐oxadiazol‐2‐(3H)‐one], pendimethalin [N‐(1‐ethylpropyl)‐3,4‐dimethyl‐2,6‐dinitrobenzenamine] and the combination of metolachlor plus atrazine. Acceptable ‘Floratam’ St. Augustinegrass color was noted following all treatments. Twelve to 24% of the stolons were unrooted 4 to 8 mo after application following treatment with 0.8kg a.i. ha−1 dithiopyr. Five to 22% of the stolons were unrooted 8 mo after treatment with isoxaben at 1.1 kg ha−1 and pendimethalin at 2.2 kg ha−1. Data collected after 8 mo showed stolon rooting to be similar to the untreated for all treatments. Turfgrass density was unaffected or slightly improved (≈25%) by herbicide treatment and was highest with oxadiazon, metolaehlor, and metolachlor plus atrazine treatments. Neither turfgrass tensile strength nor root dry weight was reduced 14 mo after treatment with any of the herbicides evaluated. Although shortterm (2 to 4 mo) negative effects followed dithiopyr, isoxaben, and pendimethalin treatments, long‐term (≥ 8 mo) effects were transient.

Tropical Signalgrass (Urochloa subquadripara) Control with Preemergence- and Postemergence-Applied Herbicides

“…This practice may also lengthen the period of effective control of tropical signalgrass. Dinitroaniline herbicides can reduce rooting and cause injury to immature turfgrass (Bingham 1974), resulting in poor root development and problems with sod slab integrity when lifting the turfgrass sod during harvest (McCarty et al 1995). McCarty et al (1995), however, reported that no long-term adverse effects occurred from a single application of dinitroaniline herbicides to St. Augustinegrass sod.…”

“…St. Augustinegrass sod production involves producing a dense, uniform, healthy stand of turfgrass; harvesting the sod; and then promoting vegetative regrowth from strips or ribbons (7 to 10 cm) of remaining turfgrass plant material to generate a subsequent crop (McCarty et al 1995). This cycle requires 8 to 14 mo to complete, leaving significant areas of bare soil open Volume 18, Issue 2 (April-June) 2004 to weed invasion for long periods (McCarty and Cisar 1989).…”

Seletividade de herbicidas aplicados na grama Batatais e na grama São Carlos

“…Em outros países, vários pesquisadores destacaram a viabilidade do uso de herbicidas aplicados em pré e pós-emergência em vá-rios tipos de gramados, a exemplo de atrazina, oxadiazon, quinclorac, sethoxydim, entre outros, bem como a possibilidade da utilização desses produtos em mistura em tanque, de forma a maximizar os efeitos dos diferentes mecanismos de ação no controle das plantas daninhas (Turner et al, 1990;McCarty et al, 1995;Johnson & Carrow, 1999;Brecke et al, 2001;Fagerness et al, 2002). Contudo, Christoffoleti & Aranda (2001) ressaltaram que não existe regra única de recomendação de herbicidas, sendo, portanto, necessárias recomendações diferenciadas, dependendo do nível de toxicidade tolerado pelo gramado.…”

Seletividade de herbicidas aplicados nas gramas Santo Agostinho e Esmeralda

“…Em outros países, vários pesquisadores destacaram a viabilidade do uso de herbicidas pré e pós-emergentes em vários tipos de gramados, a exemplo de atrazina, oxadiazon, quinclorac, sethoxydim, entre outros, bem como a possibilidade do emprego desses produtos em mistura em tanque, de forma a maximizar os efeitos dos diferentes mecanismos de ação no controle das plantas daninhas (Turner et al, 1990;McCarty et al, 1995;Johnson & Carrow, 1999;Brecke et al, 2001;Fagerness et al, 2002 Em 12/1/2006, os gramados foram cortados à altura de 3 cm com auxílio de um aparador de grama motorizado e, após dois dias, foram realizadas as aplicações dos tratamentos. As aplicações foram realizadas no período da manhã, em condições de temperatura de 27 ºC, solo úmido e umidade relativa do ar em torno de 64%.…”