Davey Tree Flipbooks

44 SHATTER CANE (Sorghum bicolor) PLANT DESCRIPTION Shatter cane, or sorghum, is a summer annual grass typically seen after midsummer growing 4–12 feet tall, with a prominent seed head that shatters apart at maturity. Shatter cane looks like corn, but is taller, has longer stems, and a much denser flower/seed head. LEAF: The leaves are very broad for a grass (2–4 inches), with a bold white center stripe. The leaf wraps around the stem where it attaches, and if peeled off reveals a tattered see-through membrane at the base. STEM: The stem is smooth and can be covered in a fine white powder. FLOWER: The densely-arranged and compact tan flower heads emerge in summer around the time corn produces flowers. SEED: Once pollinated, these flower heads become seed heads. The large seeds are round, swollen, shiny, brown, and covered in coarse hairs on wavy stems. The seed head is heavy and easily shatters apart when handled. REPRODUCTION: Seeds function as the primary means of reproduction. Most seeds fall below the parent plants but can be easily spread by equipment since seeds detach readily. The roots of shatter cane are fibrous and are unable to regenerate after winter. WHY IT IS NOXIOUS: Shatter cane is a major threat to agriculture with a mature height of over 12 feet and the ability to produce a large number of seeds. SEASONAL IDENTIFICATION WHEN TO FIND: The ideal time to find shatter cane is in midsummer after flower/seed formation. Late summer or early fall is an ideal time to spot mature seed heads. SPRING IDENTIFICATION = DIFFICULT Shatter cane is not prevalent or likely to be visible at this time. If a known colony produced seeds last year, look for seedlings in the same location. SUMMER IDENTIFICATION = EASY Summer is the ideal time to identify shattercane. The leaves are broad for a grass and have a bold white stripe down the center. Look for dense tan flower heads that look like a dust broom and are usually taller than corn. Seed heads develop by late summer as a group of large, dark, round seeds that easily shatter apart. FALL IDENTIFICATION = EASY As shatter cane fades away, the leaf center vein turns pink. Dark seed heads are visible from a distance if they are not mowed. If seeds have been removed, look for wavy seed stems. WINTER IDENTIFICATION = DIFFICULT Shatter cane does not retain any noticeable form in winter. SIMILAR-LOOKING SPECIES JOHNSONGRASS (Sorghum halapense) leaves look very similar but are narrower than shatter cane. The main difference is in the flower/seed head. Johnsongrass has a symmetrical, pyramid-shaped flower/seed head with a loose, open arrangement and smaller seeds. CORN (Zea mays) has a similar-looking leaf but is actually broader than shatter cane. Corn flower head spreads open and has several branches that resemble pipe cleaners. COMMON REED (Phragmites australis) is comparable in size but has a much more full form. The leaves are shorter and smaller with no prominent mid-vein. The flowers and seeds are lighter in color and form smaller pointed seeds. LOW HIGH ohio distribution roadside distribution growth seeds ability to dominate difficulty of control WHERE TO FIND: Shatter cane is not common in Ohio but can be randomly found in and around corn fields or fields in several locations around the state. Shatter cane favors full sun and well-drained soil. CONTROL METHODS: MECHANICAL: Seedlings can be easily controlled by tilling. Mow at the boot-to-head stage. CHEMICAL: Make directed application to shatter cane before late summer with non-selective herbicide. The ideal time for application is in the boot-to- head stage of development. After stem elongation, foliar applications are not as effective. CULTURAL: If colonies produce seed or displace desirable vegetation, plant grass in the fall so that it is established by spring. RECOMMENDATION SUMMARY: Shatter cane is a large annual grass that produces large seeds by fall. It is not difficult to control with herbicides or mowing and should not be allowed to produce seed. For best control, make directed applications before late summer with non-selective herbicide. Shatter cane has been reported as glyphosate-resistant. If using glyphosate, results should be closely monitored. Always monitor herbicide applications for effectiveness. If a second application is required for control, use alternate herbicides with different modes of action. Mow at the boot-to-head stage to provide control and prevent seed production. Failure to control shatter cane will result in a very tall grass that can cause sight distance issues and invade agriculture fields. summer annual RIVM LEVEL OF CONCERN

• Cover