PPDL Picture of the Week
May 14, 2018
Joe Ikley, Weed Science Program Specialist, Department of Botany and Plant
Pathology, Purdue University
As we emerge from our winter that
seemed to hold on forever, you may have noticed an abundance of dandelion
flowers and seedheads in the landscape. The weather last fall and this spring
appears to have been conducive to allow dandelions to thrive in many habitats.
While children will undoubtedly enjoy the abundance of seed to blow around,
those who have to manage this weed know the challenges they can face every
year, let alone when populations are as high as they are this year. Homeowners
may be used to the yearly battle against this weed, but it can also thrive in
no-till agricultural fields and on field edges.
Dandelion is a perennial weed that
has a simple taproot and can reproduce from seed, or segments of the root.
Seedlings can germinate from seed starting in late spring (after wind-blown
seed lands in a suitable habitat) and throughout early fall. Mature dandelions
will remain in a rosette that does not bolt or elongate. The only structure
that bolts from the rosette produces the familiar yellow flower and puffy white
seedhead. Being a perennial weed, control is most effective in the fall. The
best time to apply herbicides in the fall for dandelion control is after the
first light frost occurs and the plant begins moving nutrients into its
When dandelion appears in corn and
soybean fields, there are a few options for control prior to planting in the
spring. Dandelion can be effectively controlled with tillage prior to planting.
If planting no-till soybeans, a combination of glyphosate plus 2,4-D ester plus
a product containing either chlorimuron (Classic, others) or cloransulam
(FirstRate) has been most effective in our research. If planting no-till corn,
a combination of glyphosate plus 2,4-D ester plus a product containing atrazine
and mesotrione (Lexar, Acuron, others) have been most effective in our