Rhizome Johnsongrass (Sorghum halepense) Control in Corn (Zea mays) with Primisulfuron and Nicosulfuron

Abstract

In the greenhouse, soil applications of primisulfuron (40 g ai ha–1) reduced growth of emerged rhizome johnsongrass plants more than nicosulfuron (40 g ai ha–1). Both herbicides reduced growth more when applied to foliage only; a further decrease in growth did not occur for applications to both soil and foliage. Primisulfuron did not completely prevent regrowth of johnsongrass with any application method. Nicosulfuron prevented regrowth when applied to the foliage and to both soil and foliage. In single-year field studies in corn at four dryland sites and two irrigated sites, 50:50 split applications of primisulfuron (40 g ai ha–1) and nicosulfuron (35 g ai ha–1) approximately 2 wk apart provided the most consistent rhizome johnsongrass control compared with early or late single applications when visually rated 8 wk after the first application. Nicosulfuron treatments were more effective than primisulfuron treatments at both dryland sites the first year and at one of two dryland sites the second year. Primisulfuron and nicosulfuron at the irrigated site the first year were equivalent in efficacy. Nicosulfuron was more effective than primisulfuron at the irrigated site the second year. Primisulfuron or nicosulfuron treatments more than doubled corn yields at the dryland sites both years regardless of application timing. Split applications of primisulfuron or nicosulfuron provided the highest yields (approximately 80% increase over untreated plots) at the irrigated site the first year. All treatments provided equivalent yield increases (approximately 50%) the second year.

Influence of herbicide application rate and timings for post‐emergence control of Sorghum halepense (L.) Pers. maize

“…No advantage was provided by the split application treatment applied at a higher total rate. Similar results were reported by Obrigawitch et al (1990), Foy & Witt (1990, Camacho &Moshier (1991), andCamacho et al (1991). In contrast to nicosulfuron, season-long S. halepense control with rimsulfuron was less at the lower application rates.…”

“…Nicosulfuron, although tested experimentally in a similar way to rimsulfuron, has not yet been registered. Although there is a substantial number of reports on the effectiveness of nicosulfuron and primisulfuron against 5. halepense (Foy & Witt, 1990;Obrigawitch et at., 1990;Camachoera/., 1991;Camacho& Moshier, 1991;Morton et ai, 1991;Nalewaja et ai. 1991;Bhowmik et ai, 1992), published results on rimsulfuron are more limited (Palm et ai, 1989).…”

Estimation of base temperature for Sorghum halepense rhizome sprouting

“…Many pre‐emergence herbicides are able to control S. halepense seedlings, while they are less effective against ramets (McWhorter, 1989; Millhollon, 1993; Richard & Griffin, 1993). In contrast, post‐emergence sulfonylurea herbicides have been reported as an effective control measure for both S. halepense seedlings and ramets for different crops and environmental conditions (Foy & Witt, 1990; Camacho et al. , 1991; Eleftherohorinos & Kotoula‐Syka, 1995; Singh & Singh, 2004; Dalley & Richard, 2008).…”

Rimsulfuron for Postemergence Weed Control in Corn in Humid Tropical Environments of Nigeria

“…Alternatively, glyphosate may be directed at cogongrass with special application equipment, such as shields to avoid crop injury. POST control of perennial grass weeds in corn is now possible with the introduction of selective sulfonylurea herbicides, such as nicosulfuron, primisulfuron, and rimsulfuron (Camacho et al 1991;Lum et al 2004;Mitra and Bhowmik 1999). Rimsulfuron is highly effective against numerous annual and perennial weeds (Ackley 1996;Mitra and Bhowmik 1999).…”