Knowledgebase

Weed in grass hay #580788

Asked July 16, 2019, 8:56 PM EDT

Hi there, can you help identify a weed found in grass hay i purchased from a broker? I don't know which state it came from but most likely California, could be from Oregon. The weed is mostly  seed pods. The pod is small, maybe an eighth of an inch or so? Not many leaves at all. I'm feeding horses and donkeys, they do consume it.  The leaves in the pics are grass, not the leaves from the weed. Thanks! Cindy Nielsen VMD

Washoe County Nevada

Expert Response

Hi Cindy,
I believe you have a winter annual weed called Feild Pennycress. It is common in first cutting hay and is found throughout the United States. It is typically heavy in the weak sections of the field or on the edges.
I personally had the same problem several years ago and was able to have the broker take back over a ton of infested hay. The problem with the weed and horses specifically is when they feed on it, it is like needles in their gums.
Also, your property will be inundated with this plant next year and possibly the following from the seed drop. I have attached information on the weed which some people have used as a cover-crop and management techniques for next year. If you have more questions please let me know and I would be happy to help. email hansonw@unce.unr or work cell 775-399-8522
https://cropwatch.unl.edu/2018/dormant-spraying-alfalfa-weeds
https://cropwatch.unl.edu/identifying-fall-emerging-weeds  https://wric.ucdavis.edu/information/natural%20areas/wr_T/Thlaspi.pdf



Wendy Hanson Mazet Replied July 18, 2019, 6:37 PM EDT
Thank you for your time in answering! Very much appreciated. Is that the same as Virginia peppergrass,? A friend sent me a pic of the latter and it really looks exactly like it., if it was dried. I have touched the weed that's in my hay while inspecting it and never felt anything sharp or spiny. 
The Question Asker Replied July 18, 2019, 11:02 PM EDT
They are similar in appearance as they are in the same family of mustards but they are in e different genus. Also, the Peppergrass can be a perennial in some cases while Pennycress is an annual. The Peppergrass (Lepidium virginicum L.) is how you might say more fleshy and plum in stem tissue when growing and the Penneycress is in the less fleshy and small stem tissue. the needle feeling comes when the stem tissue is dry and breaks. The stem then becomes sharp and most horses push it aside and refuse to eat it.
Hope this helps.
https://plants.usda.gov/core/profile?symbol=LEVI3   https://plants.usda.gov/core/profile?symbol=THAR5

Wendy Hanson Mazet Replied July 19, 2019, 11:52 AM EDT

Loading ...