With reduced tillage, the This is an annual weed, reproducing by seeds. ... Brook says that cleavers, kochia, chickweed, spiny annual sow thistle, hemp nettle, green foxtail, wild mustard, smartweed, Russian thistle and stinkweed have all developed resistances to Group 2 herbicides. Reproducing by seed and from buds on widely spreading, creamy white, brittle, underground roots. 20 % at 5 plant/m2 … The larvae normally consume the entire receptacle and floret primordia, so attacked heads produce no seed. Prefers drier lighter soils but will tolerate heavier clay based soil if … http://www.plant.uoguelph.ca/resistant-weeds/. Perennial sow-thistle occurs throughout Ontario in cultivated fields, pastures, meadows, woodland, waste places, roadsides, gardens and occasionally in lawns. Stems can grow up to 1.5 m and leaves are found mainly at the base. 5 % at 1 plant/m2 Two Sonchus asper (spiny annual sow-thistle) biotypes, suspected of being resistant to the sulfonylurea herbicide metsulfuron-methyl, were collected in 1996 from two barley (Hordeum vulgare) fields in central Alberta, Canada.Both fields had received at least six applications of acetolactate synthase (ALS)-inhibiting herbicide(s). These are S. arvensis, perennial sow thistle, and the two annual species S. oleraceus, … Flower heads are numerous, yellow, and appear in corymbs. Flowering plants are distinguished by their showy, large, bright yellow flower heads and the covering of glandular hairs (j) on the involucre (h) and the upper stems and branches. Base of plant from perennial root. Perennial sow-thistle is not know to be toxic. h�b``�b``�������ƀ Combining biological and identifying characteristics of top interfering species along with new emerging research articles, media, and control options, weedinfo.ca provides the tools to make informed risk-reducing weed control decisions. Top 10 weeds in Alberta: 2010 survey (pre-harvest, 986 fields) •10: Crepis thtectorum (narrow-leaved hawk’s-beard) (17 in 2001) •9: Sonchus asper (spiny annual sow thistle) (41th in 2001) •8: Chenopodium album (lambsquarters) (7th in 2001) •7: Stellaria media (chickweed) (3rd in … It is not treated as an invasive plant, and many companies will control Canada thistle and scentless chamomile, but will leave the perennial sow-thistle. Brook says that cleavers, kochia, chickweed, spiny annual sow thistle, hemp nettle, green foxtail, wild mustard, smartweed, Russian thistle and stinkweed have all developed resistances to Group 2 herbicides. Richard Old, XID Services, Inc., Bugwood.org. ------------------------------------------------- Green matter in grain can increase drying costs and dockage. To find out about availability of this biocontrol agent http://www.mcclay-ecoscience.com Sow thistle, Annual <