In-Furrow Terbufos Reduces Field and Sweet Corn (Zea mays) Tolerance to Nicosulfuron

Abstract

Field experiments were conducted in Michigan, Minnesota, and Wisconsin in 1990 to explore interactions between nicosulfuron applied POST and terbufos insecticide at 0.06 or 0.11 g ai/m of row applied in-furrow on ‘Pioneer 3751’ field corn and ‘Jubilee’ sweet corn. Nicosulfuron at 0, 70, and 140 g ai/ha plus nonionic surfactant and 28% nitrogen fertilizer was applied to both corn types. Field corn response to nicosulfuron and terbufos was similar at all locations, whereas sweet corn injury varied with location. Nicosulfuron injured field corn more when applied at the four-leaf than the three-leaf stage. Injury to both corn types increased as nicosulfuron rate increased or when applied following terbufos. Nicosulfuron at 140 g/ha without terbufos did not reduce yield of either corn type; however, corn previously treated in-furrow with terbufos reduced yield.

Pyroxsulam and Chlorpyrifos Applied the Same Day Injures Wheat

“…These results indicate that compared to pyroxsulam application alone, applying chlorpyrifos and pyroxsulam in separate applications on the same day increased wheat injury by more than 50%, delayed wheat flowering by one day, and reduced mature wheat height by 8%. These results are consistent with reported interactions of soil‐applied organophosate insecticides and nicosulfuron herbicide applied postemergence in corn (9,12,16) and chlorpyrifos applied postemergence after triflusulfuron herbicide application in sugarbeet (6). Wheat response was not affected when the interval between chlorpyrifos and pyroxsulam applications was 3 or 7 days.…”

“…Herbicide and insecticide tank mixtures or sequential applications are sometimes needed to control weeds and insects simultaneously. However, herbicide‐insecticide interactions have caused crop injury and yield loss in several crops (6,8,12,16). Organophosphate insecticides reduce the rate of herbicide metabolism in crop plants by inhibiting certain enzymes such as aryl acylamidase (11) and cytochrome P450 monooxygenases (3,10).…”

Corn Response to Mesotrione as Affected by Soil Insecticide, Application Method, and Rate

“…Herbicide‐insecticide interactions have the potential to cause corn ( Zea mays L.) injury and yield loss. For example, the use of organophosphate (OP) soil insecticides in combination with sulfonylurea herbicides results in corn injury and yield losses up to 54% (2,5,6,8,9,10). OP insecticides reduce the rate at which the cytochrome P450 enzyme metabolizes sulfonylurea herbicides, resulting in a higher concentration of the herbicide remaining in the plant longer than if no insecticide was used (1,4).…”

“…Uptake and translocation of the insecticide within corn by plants may be the primary factor contributing to injury from the interaction of an OP insecticide and sulfonylurea herbicide. The availability of soil‐applied terbufos for uptake by corn is influenced by soil pH, type, organic matter, and moisture (8,9).…”

Tolerance of Three Sweet Corn Hybrids to a Postemergence Tankmix of Nicosulfuron plus Bromoxynil

“…Herbicide application was delayed at one location-year to the seven-leaf stage, which has been shown to increase nicosulfuron injury in several sweet corn hybrids (Robinson et al 1993). However, the trends indicated in this research and in the research of O' Sullivan et al (2000) indicate that the degree of plant stunting increases with increased nicosulfuron dose and is compounded by stressors such as application timing or additional xenobiotics (such as bromoxynil or certain insecticides) that are detoxified by metabolism (Morton et al, 1993;Williams and Harvey, 1996).…”