Effects of selected pesticides and adjuvants on germination and vegetative growth of Phomopsis amaranthicola, a biocontrol agent for Amaranthus spp.
Article first published online: 25 NOV 2004
Volume 44, Issue 6, pages 469–482, December 2004
How to Cite
Wyss, G. S., Charudattan, R., Rosskopf, E. N. and Littell, R. C. (2004), Effects of selected pesticides and adjuvants on germination and vegetative growth of Phomopsis amaranthicola, a biocontrol agent for Amaranthus spp. Weed Research, 44: 469–482. doi: 10.1111/j.1365-3180.2004.00425.x
- Issue published online: 25 NOV 2004
- Article first published online: 25 NOV 2004
- Received 13 December 2002 Revised version accepted 24 September 2004
- Amaranthus spp.;
- biological control;
- Phomopsis amaranthicola
Phomopsis amaranthicola, a bioherbicide agent for Amaranthus spp., was tested in vitro for its compatibility with commercial formulations of 16 adjuvants, 24 herbicides, nine fungicides and four insecticides at 2X, 1X (highest labelled product dose rate), 0.75X, 0.5X and 0.25X concentrations. These chemicals were tested for their effects on spore germination. Selected herbicides and fungicides at 1X were also tested for their influence on colony growth and sporulation. All tested compounds were finally categorized in compatibility classes regarding germination, mycelial growth and sporulation such as low, medium and high compatibility. High compatibility in terms of germination and fungal colony growth was only observed with the herbicide bentazone. Many of the adjuvants tested were highly compatible in the germination studies. Most fungicides and insecticides had medium and low compatibility with P. amaranthicola. Effects of pesticides on spore germination did not fully correspond with their effects on colony growth. Thus, it is possible to integrate the use of P. amaranthicola with some herbicides, fungicides, insecticides and adjuvants but not others. A case-by-case selection of application methods, such as tank-mix or sequential application, along with proper timing of applications of the fungus and the chemical agents will be necessary.