Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 15, 2008
Publication Date: December 1, 2008
Citation: Boydston, R.A., Collins, H.P., Alva, A.K. 2008. Control of Volunteer Potato (Solanum tuberosum) in Sweet Corn with Mesotrione Unaffected by Atrazine or Tillage. Weed Technology. 22:654-659. Interpretive Summary: Volunteer potato is a recurring weed problem in regions where winter soil temperatures fail to drop below the -1.5 C threshold necessary to kill tubers remaining in the soil after potato harvest. Several herbicides suppress volunteer potatoes, but plants are seldom killed. Surviving plants often continue to produce small tubers leading to volunteer potato problems for several subsequent years. Volunteer potato control in field corn and sweet corn has improved substantially in recent years with the use of mesotrione applied POST. Applying atrazine with mesotrione may improve volunteer potato control or allow for reduced herbicide rates. Reduced tillage systems are increasingly being used due to benefits of decreased soil erosion and increased profitability. The effectiveness of mesotrione on volunteer potato has not been evaluated in reduced tillage systems. These studies were conducted to 1) determine if the addition of atrazine improved volunteer potato control in sweet corn with mesotrione and 2) determine the efficacy of mesotrione and fluroxypyr on volunteer potato in sweet corn grown under reduced tillage and conventional tillage systems. Mesotrione applied alone at all rates, atrazine at 1.1 kg/ha, or mesotrione plus atrazine combinations nearly eliminated the number of new tubers produced on volunteer potatoes. Lower rates of atrazine alone were not as effective. Control of volunteer potato with fluroxypyr was improved in conventional tillage plots due to the cultivation following the herbicide application, whereas control of volunteer potato with fluroxypyr in reduced tillage plots was not complete. Control of volunteer potato with mesotrione was greater than 98% and reduced tuber number and weight greater than or equal to all other treatments regardless of tillage level. Mesotrione alone or in tank mixes with atrazine can be utilized by growers to control volunteer potatoes well in both conventional and reduced tillage systems
Technical Abstract: Volunteer potato is a major weed pest of sweet corn in regions where winter soil temperatures fail to kill tubers left in the ground after harvest. Studies were conducted in 2004 to 2005 to determine the effect of combining atrazine with mesotrione applied postemergence (POST) on volunteer potato control and new tuber production in sweet corn. Mesotrione at 0.035, 0.07, and 0.1 kg/ha and atrazine at 0.3, 0.6, and 1.1 kg/ha were applied alone and in all possible combinations when volunteer potato ranged from 5 to 12 cm tall. Mesotrione applied alone at all rates, atrazine at 1.1 kg/ha, or mesotrione plus atrazine combinations reduced the number of new tubers produced to = 1.1 per plant compared with 11 tubers per plant in nontreated checks. Potatoes treated with atrazine alone at 0.3 or 0.6 kg/ha produced 3.3 and 1.9 tubers per plant, respectively, which could lead to volunteer potato problems in the succeeding crop. Sweet corn yield was not affected by herbicide treatment in 2004 but was reduced in 2005 where atrazine was used alone at 0.3 or 0.6 kg/ha due to poor volunteer potato control. Additional studies were conducted from 2004 to 2006 to determine volunteer potato control in sweet corn in reduced (RT) and conventional (CT) tillage and treated with fluroxypyr, mesotrione, or no herbicide. Volunteer potato control was improved and the number and weight of tubers was reduced 79 and 91%, respectively, in CT plots treated with fluroxypyr compared with RT plots. Control of volunteer potato with mesotrione was greater than 98% and reduced tuber number and weight greater than or equal to all other treatments regardless of tillage level.