Incidence ofColletotrichumspp. on Soybeans and Weeds in Illinois and Pathogenicity ofColletotrichum truncatum

Abstract

The weeds sampled and assayed were velvetleaf (Abutilon theophrasti Medic.), Colletotrichum destructivum, C. truncatum, and Glomerella glycines occurred on 22% of stubble rough pigweed (Amaranthus retroflexus

Latent colonization byColletotrichumspp.: Epidemiological considerations and implications for mycoherbicides

“…Latent colonization by Colletotrichum spp. on soybeans as well as other legumes has been reported (27,39,40,65,66). In addition, Phomopsis spp.…”

“…Subsequently, this technique was used in a field study of the effect of environmental conditions upon infection and latent colonization of soybean plants by P. longicolla (50), and in studies of epidemiology and latent colonization by Colletotrichum spp. in soybean and weed tissues (27,39,40) and by Phomopsis leptostromiformis [Kuhn] Bubak ex CERKAUSKAS: COLLETOTRICHUM/MYCOHERBICIDES 307 Lind in lupin in Western Australia (18). It was used also to enhance the recovery of Cercospora canescens Ellis and Martin from bean tissue in Brazil (22).…”

“…The method used for surface disinfestation and detection of latent colonization was similiar to that employed by Cerkauskas et al (15) and subse quently shown to be effective in other hostpathogen combinations (27,39). Stem pieces from each treatment were washed in tap water for 16-20 h. These pieces were agitated (51) in 70% ethanol for 5 sec, then in 0.5% NaOCl (10% Clorox) for 4 min.…”

“…(27,38,48,53,65,66), and by other fungi, such as Phomopsis spp., on soybean {Glycine max (L.) Merr.) (31)(32)(33)(34) and other hosts (13,33), is of epidemiological significance for disease develop ment (27,32,48,52). Latent colonization by these fungi is not evident until a change occurs in the physiological state of the maturing host tissue.…”

Anthracnose of Christmas rose caused by Colletotrichum sp.

“…It is pathogenic to species in six genera and is highly virulent to most cultivars of pea (Weidemann et al 1988). On the other hand, C. truncatum was isolated from 14 nonleguminous weeds, and some isolates were pathogenic to soybean (Hartman et al 1986). Perhaps C. truncatum can infect a wide range of plant species other than legumes.…”