Effects of Multiple Applications of Simulated Quinclorac Drift Rates on Tomato

Abstract

Quinclorac drift has been speculated as the cause of injury to tomato crops throughout northeast Arkansas. In this study, we set out to determine whether tomato plant injury and yield reduction were correlated with simulated quinclorac drift. Experiments were carried out at Fayetteville, AR, in 1999 and 2000. Maximum plant injury (visual ratings) was about 20% when plants were treated with one, two, or three quinclorac applications (weekly intervals beginning at first flower) at 0.42 g ai ha−1(0.001 times the normal use rate to simulate drift). Maximum plant injury ranged from 48 to 68% with quinclorac simulated drift treatment of 42 g ha−1. Overall, increasing quinclorac rate and number of applications increased tomato injury. In both years, tomato plant fresh-weight accumulation was not influenced by one, two, or three applications of quinclorac at 0.42 g ha−1compared with the untreated control. In 1999, increasing the rate of quinclorac from 0.42 to 4.2 g ha−1reduced plant fresh-weight accumulation. In 2000, there was no significant difference in plant fresh weight when plants were treated with quinclorac at 2.1 to 4.2 g ha−1. Evaluation of the herbicide rate effect indicated that quinclorac at 0.42 g ha−1did not reduce tomato fruit yield (total weight of edible fruit) compared with the untreated control, but yield decreased as rate increased above 0.42 g ha−1. Increasing the number of applications generally decreased tomato yield, and overall as maximum visual plant injury increased, tomato yield reduction ALSo increased linearly. We conclude that quinclorac at simulated drift rates can adversely affect tomato plant growth and yield.

Evaluation of auxin tolerance in selected tomato germplasm under greenhouse and field conditions

“…Factors included three herbicides (2,4-D, dicamba, and quinclorac) and nontreated (without herbicide) and five tomato varieties (three wild accessions: TOM199, TOM198, and TOM300; two tomato cultivars: Money Maker and Better Boy). The 2,4-D, dicamba and quinclorac were applied at simulated drift rates of 11.2 g ae ha −1 (0.01X) (Fagliari et al 2005), 2.8 g ae ha −1 (0.01X) (Kruger et al 2012), and 39.2 g ae ha −1 (0.01X) (Lovelace et al 2007), respectively. Herbicides were obtained commercially as follows: 2,4-D dimethylamine salt (Weedar 64, Nufarm Inc, Alsip, IL), quinclorac (Facet ® , BASF Corp., Florham Park, NJ), and dicamba (Clarity, BASF Corp., Florham Park, NJ).…”

“…The study reported that a maximum injury of 20% occurred when plants were treated with either one, two, or three quinclorac applications, at 0.42 g ai ha −1 , in both 1999 and 2000. Additionally, a reduction in plant fresh-weight accumulation was observed when quinclorac rate was increased from 0.42 to 4.2 g ai ha −1 (Lovelace et al 2007). Lovelace et al (2009) reported an increase in quinclorac residue in tomato tissue due to an increase in rate and number of quinclorac applications.…”

“…Tomato is highly sensitive to some herbicides, particularly auxins, and drift of these herbicides onto tomato can lead to economic losses to farmers (Lovelace et al 2009;Romanowski 1980;Schmoll et al 2000). Off-target movement of auxin herbicides can cause economic losses by affecting yield production directly or by impacting the growth stages (vegetative and reproductive) (Christoffoleti et al 2015;Hemphill and Montgomery 1981;Kruger et al 2012;Lovelace et al 2007;Pazmiño et al 2011;Romero-Puertas et al 2004). Lovelace et al (2007) conducted a 2-yr experiment to detect the influence of quinclorac drift on tomato plant, particularly fruit yield.…”

“…Off-target movement of auxin herbicides can cause economic losses by affecting yield production directly or by impacting the growth stages (vegetative and reproductive) (Christoffoleti et al 2015;Hemphill and Montgomery 1981;Kruger et al 2012;Lovelace et al 2007;Pazmiño et al 2011;Romero-Puertas et al 2004). Lovelace et al (2007) conducted a 2-yr experiment to detect the influence of quinclorac drift on tomato plant, particularly fruit yield. The study reported that a maximum injury of 20% occurred when plants were treated with either one, two, or three quinclorac applications, at 0.42 g ai ha −1 , in both 1999 and 2000.…”

Effects of single and multiple applications of glyphosate or aminopyralid on simple constructed plant communities

“…A few experiments with multiple exposures have been performed using terrestrial plants. Lovelace et al found that injury and yield reductions in general increased with multiple applications of quinclorac at drift rates. When grapes received up to 3 exposures of 1 of the several sulfonylurea herbicides tested, the effects were additive .…”