World of Weed: Morningglory

 

Morningglories (Ipomoea spp) are troublesome weeds that often escape pre-emergent herbicide applications and have the ability to reduce yields and harvest efficiency. This month, we will take a look at some of the morningglory species found in Kansas cropping systems.

 

 

Morningglories are categorized in the genus Ipomoea. Morningglory species commonly found in Kansas include ivyleaf morningglory, pitted morningglory, and tall morningglory (Figure 1). They can be found in a variety of places, including fields, pastures, gardens, and roadsides. These species are native to tropical and subtropical regions of the Americas. Their distribution has been aided by the horticultural appeal of the flowers.

 

 

 

Morningglories are vining plants that can reach up to 10 feet long. The cotyledons of morningglories resemble butterfly wings (ivyleaf and tall morningglory) or a ‘V’ (pitted morningglory). The leaves are alternate. Pitted and tall morningglory have heart-shaped leaves (Figure 2), but ivyleaf morningglory leaves can be three-lobed or heart-shaped. Pitted morningglory leaves do not have hairs, but tall morningglory has hairs that lie flat against the leaf surface and ivyleaf morningglory leaves have hairs that stick out. Flowers are trumpet-shaped and generally light blue, purple, pink, or white. Each flower forms a round capsule that contains 2-6 seeds. Seeds are dark brown or black and resemble and orange slice.

 

 

 

Morningglories can be difficult to control with pre-emergence herbicides due to their large seed size and thick seed coat. They may also escape control by pre-emergence herbicide by germinating later in the growing season. Herbicides that contain atrazine, or Group 14 herbicides, such as Sharpen, Spartan, or Valor can provide pre-emergence control. Emerged morningglories are typically not well controlled by glyphosate, but can be controlled by timely applications of glufosinate (Liberty), dicamba, or 2,4-D.