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Experiments examining burcucumber management in glufosinate-resistant (GR) and imidazolinone-resistant (IMI) corn were conducted in 1997 and 1998 in southeastern Pennsylvania. GR corn was planted in 38- and 76-cm rows, and postemergence (POST) treatments of glufosinate and glufosinate plus atrazine were applied to corn at the V4 or V5 growth stage. In a second study, IMI corn was planted in 76-cm rows, and 15 preemergence (PRE) and POST herbicide programs were evaluated. Herbicide treatments included RPA-201772, CGA 152005, simazine, imazethapyr plus imazapyr, imazamox, chlorimuron plus thifensulfuron, nicosulfuron plus rimsulfuron plus atrazine, CGA 152005 plus primisulfuron, and combinations with atrazine. Burcucumber germinated throughout the growing season, with greatest emergence occurring in early June, gradually decreasing to minimal emergence by mid-July. Glufosinate alone controlled burcucumber 79 to 90% 7 weeks after planting (WAP) regardless of application timing or row spacing. By 10...

An experiment was conducted in 1998 and 1999 in southeastern Pennsylvania to examine the effect of tillage and soybean row spacing on burcucumber emergence and growth. A second experiment evaluated postemergence (POST) soybean herbicides on burcucumber control. In the tillage and row spacing study, a glyphosate-resistant soybean variety was planted in no-till and reduced-tillage systems in 38- and 76-cm row spacings. In the POST herbicide experiment, chlorimuron, glyphosate, CGA-277476, thifensulfuron, and several combinations of these herbicides were applied at two different POST application timings in 38-cm row soybean planted in a reduced-tillage system. In the tillage and row spacing study, burcucumber emergence was greatest starting in late May through mid-June and mostly ceased by early July, regardless of tillage system or row spacing. Although there was no difference in germination period in either tillage system, preplant tillage increased the number of emerged plants by 110% in 1997 an...

A postemergence (POST) timing study was conducted on established populations of bur- cucumber (Sicyos angulatus) in corn (Zea mays), and a second study examined the residual activity of several herbicides for burcucumber control under greenhouse conditions. In the field study, flum- iclorac, halosulfuron, primisulfuron, CGA 152005, and CGA 152005 + primisulfuron (45, 71, 40, 40, and 20 + 20 g ai/ha, respectively) were applied at two POST timings. CGA 152005, primisul- furon, and the combination provided greater than 85% control of burcucumber 14 wk after planting (WAP). Flumiclorac and halosulfuron provided 60% control or less by 8 WAP. Timing of the POST applications did not influence burcucumber control by 11 WAP with any herbicide. In the greenhouse, germinated burcucumber seeds were placed in soil treated with atrazine, chlorimuron, primisulfuron, or CGA 152005 at normal field use rates. All treatments provided similar residual control early; however by 4 wk after treatment (WAT), control from atrazine was less than 10% compared to 69% for chlorimuron and about 50% for primisulfuron and CGA 152005. This research suggests that CGA 152005 and primisulfuron can both be effective for managing burcucumber in corn, whereas flum- iclorac and halosulfuron proved ineffective. Nomenclature: Atrazine, 6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine; chlorimu- ron, ethyl 2-(((((4-chloro-6-methoxy-2-pyrimidinyl)amino)carbonyl)amino)sulfonyl)benzoate; flumi- clorac, (2-chloro-4-fluoro-5-(1,3,4,5,6,7-hexahydro-1,3-dioxo-2H-isoindol-2-yl)phenoxy)acetic acid; halosulfuron, methyl 5-(((4-,6-dimethoxy-2-pyrimidinyl)amino)carbonylaminosulfonyl)-3-chloro- 1- methyl-1-H-pyrazol-4-carboxylate; primisulfuron, methyl 2-(((((4,6-bis(difluoromethoxy)-2-pyrimi- dinyl)amino)carbonyl)amino)sulfonyl)benzoate; CGA 152005 (proposed name, prosulfuron), 1-(4- methoxy-6-methyl-triazin-2-yl)-3-(2-(3,3,3-trifluoropropyl)-phenylsulfonyl)-urea; burcucumber, Sicy- os angulatus L. #3 SYCAN; corn, Zea mays L. Additional index words: Herbicide application timing, residual control. Abbreviations: EPOST, early postemergence; POST, postemergence; PRE, preemergence; WAP, weeks after planting; WAT, weeks after treatment.