Effect of Foramsulfuron and Isoxaflutole Residues on Rotational Vegetable Crops

Abstract

<jats:p>There is little information published on the effect of residues from postemergence (POST) applications of foramsulfuron and preemergence (PRE) applications of isoxaflutole, and isoxaflutole plus atrazine in the year after application on vegetable crops. Three trials were established from 2000 to 2002 in Ontario to determine the effects of residues of foramsulfuron, isoxaflutole, and isoxaflutole plus atrazine on cabbage, processing pea, potato, sugar beet, and tomato 1 year after application. Aside from a reduction in sugar beet plant stand, there were no visual injury symptoms in any crop at 7, 14, and 28 days after emergence (DAE) in any of the herbicide carryover treatments. Isoxaflutole residues reduced shoot dry weight and yield as much as 27% and 28% in cabbage, and 57% and 60% in sugar beets, respectively. The addition of atrazine to isoxaflutole caused further reductions in shoot dry weight and yield of cabbage and sugar beet. Isoxaflutole plus atrazine residues reduced shoot dry weight and yield as much as 42% and 43% in cabbage, and 58% and 82% in sugar beets, respectively. There were no adverse effects on shoot dry weight and yield of processing pea, potato, and tomato from isoxaflutole or isoxaflutole plus atrazine residues in the year following application. Foramsulfuron residues at either rate did not reduce shoot dry weight or yield of any crops 1 year after application. Based on these results, it is recommended that cabbage and sugar beet not be grown in the year following the PRE application of isoxaflutole or isoxaflutole plus atrazine.</jats:p>

Atrazine Accentuates Carryover Injury from Mesotrione in Vegetable Crops

“…Although potato might be injured by residues of imazethapyr or imazamox (O'Sullivan et al 1998), other studies have reported little adverse effects on potato yield 1 yr after application of nicosulfuron or flumetsulam (Greenland 2003;O'Sullivan et al 1999). Isoxaflutole, and isoxaflutole plus atrazine residues did not cause injury or yield loss in potato the year after herbicide application (Soltani et al 2005). Injury, plant dry weight reductions, and yield losses occurred at both rates of mesotrione and mesotrione plus atrazine in broccoli, carrot, cucumber, and onion, but not in potato.…”

“…Broccoli dry weight and yield were less in both mesotrione plus atrazine tank mix treatments than either mesotrione or atrazine applied alone (Table 2). Soltani et al (2005) observed that when atrazine was added to isoxaflutole, the combination caused greater carryover injury to cabbage than when isoxaflutole had been applied alone the year before transplanting. Injury, reductions in plant dry weight, and yield losses were observed when mesotrione and the tank mix of mesotrione plus atrazine were applied 1 yr prior to planting carrot (Table 3).…”

“…This also provides producers an opportunity to utilize the wider array of field corn herbicides to manage weeds that are difficult to control in vegetables. Vegetable crops differ in their response to residues from herbicides applied in previous years (Felix and Doohan 2005;Felix et al 2007;Greenland 2003;Soltani et al 2005). The potential for herbicide carryover to reduce vegetable crop yield is a significant concern for producers of these high-value crops.…”

“…Mesotrione is not a stand-alone herbicide; rather, it is applied along with atrazine to ensure acceptable control of a wider range of broadleaf weeds than mesotrione can control on its own (Armel et al 2003;Bollman et al 2006), and might help reduce the selection for herbicide-resistant weeds (Shaner et al 1997). The addition of atrazine to isoxaflutole, another HPPDinhibiting herbicide, caused greater carryover injury to high value crops such as cabbage, sugar beet (Soltani et al 2005), and cranberry and black bean (Robinson et al 2006) than isoxaflutole alone. This is of concern for vegetable producers, because there are no published data that have demonstrated whether applying mesotrione with atrazine increases the potential for carryover injury.…”

Plant Pigments Content as a Marker for Herbicide Abiotic Stress in Corn (Zea mays L.)

“…Moreover, the toxic effect of isoxaflutole residues was established in vegetable crops as adzuki bean, alfalfa, carrot, cucumber, dry bean (navy and black beans), onion, sugar beet, tomato (Nelson and Penner 2005), cabbage and sugarbeets (Soltani et al, 2005), tomato, bell pepper, cabbage, snapbean and cucumber (Felix and Doohan, 2005). The active substance distributed through the vascular tissue acts as an inhibitor of plant pigment biosynthesis (Pallett et al, 1998).…”