The IR-4 Project, a significant resource for supplying pest management tools for specialty crop growers based on stakeholder input and peer-reviewed research, has released its 2016 Ornamental Horticulture Program weed science research update. The report covers the following studies:

  • In Season Pre-emergent Herbicide Crop Safety
  • Ornamental Grass Crop Safety
  • Bulb Herbicide Crop Safety (a subset of the Pre-emergent study)
  • Flumioxazin + Pyroxasulfone Crop Safety

In the In Season Pre-emergent Herbicide study, 11 products were tested and evaluated for phytotoxicity on a scale of 0 to 10; 1, 2 and 4 weeks after each application, for a total of 144 planned trials. The study showed that Biathlon (oxyfluorfen + prodiamine), produced minimal to low injury on most crops screened; Quercus species can be added to the label for F6875 4SC (sulfentrazone + prodiamine); Leucothoe, Gaillardia and Paeonia can be added to the label for Freehand G (pendimethalin + dimethenamid-p), but Echeveria may need to be labeled off; SP1770 appears to cause significant injury so far; and Itea virginica and Sabal minor can be added to the label for Tower (dimethenamid-p).

The Ornamental Grass Crop Safety Project identified 22 product-crop combinations that can be added to respective labels. Summary results show:

Dimension 2EW – all but two grasses screened so far showed no or low injury with over the top applications (exceptions were Festuca ovina and Muhlenbergia dubia); Gallery DF/SC – all but two grasses screened so far showed no or low injury with over the top applications (exceptions were Festuca glauca and Deschampsia caespitosa); Pendulum 2G (pendimethalin) – all grasses tested to date exhibited no to minimal injury with over the top applications; and new crops can be added to Dimension – 11, Gallery – 4, and Pendulum – 7.