Rust in Orchardgrass Hay Fields:
There are numerous grass hay fields and pastures this summer with rust diseases. Second cutting orchardgrass seems to be the most affected grass species. Here are some comments by Cindy Ocamb, Botany and Plant Pathology Extension Specialist:
“Orchardgrass can be affected by rust diseases, three to be exact; crown rust, stem rust, and stripe rust. A sample submitted to the OSU plant clinic would be the best way to determine which rust is occurring in the orchardgrass hay fields.”
Here's the Plant Disease Handbook link to rust in grass seed crops http://pnwhandbooks.org/plantdisease/grass-seed-rusts
“Unfortunately there are no fungicides labeled for grass hay crops or pasture. As can be seen from the handbook, products are only labeled for use on grass grown for seed.”
If irrigating, water in the morning so that grass plants have time to dry during the afternoon and evening. Rust diseases can increase with moisture so make sure plants are dry before night time.
"Endophyte Toxins in Grass Seed Fields and Straw. EM 8598. August, 2003."
Endophyte levels for some Oregon grown grasses are available on a list prepared by three Oregon State University Extension Crop Science faculty. The list was updated in 2006.
"Haymaking on the westside. EB 1897." A publication on conserving hay in western Washington and western Oregon written by Steven Fransen and Michael Hackett of Washington State University.
What to Look for in Evaluating Hay (PDF, 5MB)
Purchasing weed free hay or straw: Questions often come from horse owners who are heading to camping areas that require certified weed free forage for the animals. The Oregon Department of Agriculture does the certification and also has a list of sellers.
"Oregon Grass Straw" - an affordable forage resource for winter feeding programs. 1999. Randy Dovel, Tim DelCurto and Gene Pirelli. Available only from the Polk County Extension office.
Agriculture Fiber Association publication. Available only from the. Please call to ask for a copy.