Apple IPM- Mile-a-Minute

Persicaria perfoliata (mile-a-minute, Asiatic tear-thumb) is an invasive weed species native to India and Eastern Asia. Reports of established populations of mile-a-minute have been confirmed in 17 U. S. states, including Massachusetts and the District of Columbia. This annual, herbaceous weedy vine grows rapidly, as much as six inches in one day. This allows mile-a-minute to cover ground, and crops, quickly. Once it has grown over a crop, herbicide is no longer a viable management method as any material applied will also affect the desirable plants beneath. 

ID/Life Cycle:  

Mile-a-minute is an annual weed in the family Polygonaceae also known as the knot/smart weed family. There are a number of other species in this family considered invasive in Massachusetts. This family of plants is characterized by “ocrea”, a leaf like sheath that encircles the stem at the base of a leaf petiole. As the plant grows the stems become reddish colored and are covered in reflexed (hooked barb faces away from the growing shoot tip) barbs. The plant uses these barbs to hold onto to plants and other objects in its path allowing it to grow over anything it encounters. Mile-a-minute may flower as early as June. Most flowers are produced in July and August. Flowers are inconspicuous, greenish-white to yellow and grow on shoot ends and in leaf axils. Seeds begin as a metallic blue berry like structure. As seeds ripen, mid-September into November, they darken and develop a paper like covering. Seeds lay dormant overwinter and sprout the following spring. Seedlings grow rapidly through spring and early summer.     

Damage:

Mile-a-minute impacts plant health indirectly by blocking sunlight, inhibiting photosynthetic capacity of desirable plants.  If allowed to climb into crops, the barbs make harvest problematic as they readily snag clothing and skin. Mile-a-minute rapidly colonizes herbicide treated weed free strips where, in apple, it can rapidly grow into the crop out competing newly planted trees, potentially even breaking them and negatively impacting the “pick your own” experience. This weed’s ability to quickly make its way into the tree canopy also makes herbicide application timing critical as mile-a-minute cannot be treated in the canopy.

Management Strategies

Monitoring:

Look for seedlings emerging in the spring. These will already have the characteristic reflexed barbs on the stems and main vein of the new leaves and most easily seen on bare soil, i.e. in orchard rows, and driveway berms.

Cultural/Biological

A weevil, Rhinoncomimus latipes, has been identified as a viable biological control of mile-a-minute and released at several sites in MA and other states where this invasive pant has been confirmed. The adult weevil feeds on the plant, lays its eggs on the stem into which the larvae bore and complete the life cycle. This causes reduced seed production and even plant death. Populations of this weevil are being monitored to confirm they have become established in relation to the invasive weed population.

Chemical

• Glyphosate is effective as a burn down. Pre-emergent materials may also be used but check labels for crop specific restrictions (non-bearing apple only, for example)

• Refer to the New England Tree Fruit Management Guide for specific materials and rates recommended for managing annual weeds.

Date: May 2021

Additional information available on the MYIPM app: https://apps.bugwood.org/apps/myipmseries/