Submitted to: Washington State Weed Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 15, 1993
Publication Date: N/A
Interpretive Summary: Approximately three to four times as many potato tubers are left in the field after harvesting than are planted in the spring. Tubers that survive the winter are a serious weed problem in potato rotations. Volunteer potatoes harbor diseases, insects, and nematodes that can reinfect neighboring potato fields. Volunteer potatoes also compete with the rotational crop for light, water, and nutrients. The following practices will reduce volunteer potatoes in rotational crops: 1) Leave less volunteer potatoes in the field; 2) Don't fall plow after harvesting and prevent deep burial of tubers in the fall; 3) Rotate to a competitive crop such as winter wheat or corn; and 4) Apply effective herbicides and timely cultivations, when possible, in the rotational crop. Combining these practices has resulted in greater than 95% control of volunteer potatoes.
Technical Abstract: Volunteer potatoes are difficult to control in potato rotations. Most tubers left in the field are less than 10 centimeters deep and are not likely to survive cold winter temperatures. About 6% of the tubers left in the field are buried deeper than 10 centimeters and can frequently survive overwinter. Discing and planting wheat, paraplowing, subsoiling and packing, and discing and packing all did not bury tubers any deeper than no-tillage and will help keep tubers near the soil surface where they are more likely to be killed by cold winter temperatures. In a corn crop, cyanazine applied preemergence alone or followed by 2,4-D postemergence controlled volunteer potatoes better than four postemergence herbicide treatments.