Effects of Chlorpropham Vapors on Dodder Seedlings

Abstract

Dodder (Cuscuta spp.) seedlings were killed when exposed to isopropyl m-chlorocarbanilate (chlorpropham) vapors in an enclosed system or in the open atmosphere in the greenhouse or field. No seedlings wrapped on the host when they were exposed for 16 hr or more in an enclosed system. Alfalfa (Medicago sativa L.) foliage restricted air movement near the treated soil and favored accumulation of vapors that killed emerged and emerging seedlings.

Movement of Chlorpropham after Application to Soil for Control of Dodder (Cuscutaspp.)

“…These results corroborate those of Slater et al (6). They found that vapors of chlorpropham killed dodder seedlings, and that air passing over treated soil could carry vapors away and reduce the effect on dodder.…”

“…Vdpor movement from treated soil. In two experiments, dodder seeded in untreated soil was exposed to vapors arising from soil treated with chlorpropham, by use of a technique similar to that described by Slater et al (6). The dodderseeded soil in each metal can formed a matrix into which were inserted 20 glass test tubes (12 by 75 mm), each of which was filled to within 6 mm of the top with dodder-seeded soil.…”

“…Danielson (1) reported that granular formulations of chlorpropham emitted phytotoxic vapors. Slater et al (6) demonstrated that chlorpropham applied to the soil surface as a granular formulation killed dodder by contacting the seedlings as a vapor above the soil surface.…”

Control of Dodder(Cuscutaspp.) with Pronamide

“…Chlorpropham is volatile, and much of its control of dodder results from vapors that contact seedlings above the soil surface (14). Using methods previously described for other herbicides (5,14), the response of dodder to vapors that might come from pronamide-treated soil was measured in a green house experiment.…”

Postattachment Control of Swamp Dodder (Cuscuta gronovii) in Cranberry (Vaccinium macrocarpon) and Carrot (Daucus carota)

“…Chlorpropham (1-methylethyl 3-chlorophenylcarbamate) is the standard preemergence (PRE) herbicide treatment for dodder (Cuscuta spp.) control (8), although growers of susceptible crops often do not obtain full-season control (5,7,9,14).…”