Efficacy of Trematophoma lignicola Petrak as a Biological Control Agent for Amaranthus retroflexus L.

The biology of Canadian weeds. 130. Amaranthus retroflexus L., A. powellii S. Watson and A. hybridus L.

“…has focused, with promising results, on other fungal species: Alternaria alternata (Fr.) Keissler and Trematophoma lignicola (Petrak) (Ghorbani et al 2000;Lawrie et al 2001; and literature reviewed by Bürki et al 2001a, b).…”

Outdoor Studies of the Efficacy of Alternaria alternata in Controlling Amaranthus retroflexus

“…However, there must be some doubt as to whether further reduction is realistic, as little or no disease establishment or weed growth reduction was obtained at 40 L ha -1 (Edmund, 2000) or 100 L ha -1 (Lawrie, 1999). Nevertheless, work by Boyette (1994) indicated that increasing the oil content to 50% (v/v) in the emulsion permitted the applicatio n rate to be reduced to 5 L ha -1 .…”

“…Also factors such as the eVect of the boundar y layer around the target and wind movements can prevent conidia from reaching the weed target (Matthews, 1992). Furthermore, conidia can be lost from the spray droplet in¯ight (Lawrie, 1999), this eVect being dependant on inoculum concentration.…”

“…alternata was grown in 250 ml conical¯asks containing 3 g chopped wheat straw and 30 ml of a 10% (v/v) V8 Juice (Campbell Grocery Products Ltd, King's Lynn, UK) in deionized water, adjusted to pH 6 (Lawrie, 1999) and then sterilized in an autoclave. Thē asks were inoculated, under sterile conditions, with two 3-mm diameter plugs of A. alternata, isolated from 7-day old V8 juice-agar plates (Johnston & Booth, 1983).…”

“…retroXexus plant in one pot was removed 3 DAT. The leaves were cleared (Lawrie et al, 2001) and examined microscopically with bright ® eld illumination at a magni® cation of 3 125. Ten microscope ® elds, ® ve either side of the mid-rib, were examined for each leaf and the numbers of germinated and non-germinated conidia determined and recorded.…”