A weed that is showing up more and is being blamed on direct seeding is dandelion. This weed is well adapted to field conditions when there is no tillage. In order to set a management practice to control dandelion in a direct seeding system we must first understand it's growing habits.
Dandelion is a perennial that grows from a taproot many feet long.
It reproduces from seeds to produce new plants while the original plant sends up new shoots from the root crown. The seeds are produced throughout the growing season and germination of these seeds can occur anytime throughout the summer. At any particular time of the year you may have newly germinated dandelion plants less than 1 inch in diameter as well as large perennial plants greater than 1 foot in diameter. Once dandelions have developed into a large perennial plant, shallow tillage will not control them. All that happens is the top of the plant is cut off and it regrows from the crown.