Paspalum (Paspalum dilatatum) is a difficult-to-control, warm-season, rhizomatous, perennial grassy weed. Paspalum is native to South America. It is a major weed particularly in the sub-tropical regions of Australia, although it is also a problem in all southern states as well.
Historically, repeated applications of organic arsenicals (MSMA, DSMA) have been used with inconsistent results. Recent introduction of the post-emergent herbicide Tribute® has provided a new tool to effectively control paspalum in a planned program of herbicide applications.
What to look for
Paspalum is a large, course-textured, clump-forming, warm-season perennial weed. These clumps can be very unsightly in desirable golf turf and will continue to increase in size if not controlled. Paspalum develops short, thick rhizomes and spreads via these rhizomes as well as seed. This weed has a distinctive greyish-green colour with rather large leaves, 6–13 mm wide. It also produces a large seedhead and is a heavy seed producer.
Tribute can be used on both couchgrass and zoysiagrass. The following points need to be considered for success in controlling paspalum with Tribute:
- Application timing is critical for success for optimum paspalum control; applications outside the ideal timing will provide paspalum suppression.
- Initial application timing should be in the late summer/early autumn while the paspalum is still actively growing and not under stress (e.g., water stress/drought conditions).
- Applying a systemic herbicide, such as Tribute, during this period promotes movement of the active ingredients down to the roots, aiding in effective control.
- A programmed approach of DSMA or MSMA followed by two applications of Tribute at 14-day intervals has been shown to give the best control.
- Always read and follow label directions.
||% Paspalum control at 37 days
Apply Tribute at 2 litres per hectare for the control of paspalum. Make one or two application at a 14-day interval following an application of an MSMA or DSMA product at label rate. The pre-treatment with MSMA or DSMA increases the uptake and translocation of the subsequent Tribute applications.
Trials have shown that best control is achieved from autumn applications.
Paspalum controlled with Tribute/DSMA. Photos: Bayer CropScience.