Evaluation of five pre-emergence herbicides for volunteer potato (<i>Solanum tuberosum</i> L.) control

Abstract

Volunteer potatoes can cause significant weed problems in crops following potatoes as large numbers of potato tubers remain behind in the field after mechanical harvesting. These volunteer plants can create havoc with rotation programs and serve as a source of pests and diseases. The aim of this project was to identify a suitable product to control volunteer potato plants. A glasshouse trial was conducted in polyethylene pots filled with a sandy soil (9% clay). Two potato cultivars (Mondial and Sifra) and five pre-emergence herbicides (atrazine, clomazone, imazethapyr, mesotrione and picloram), together with a soil fumigant (metham potassium) and an untreated control were used in a randomised complete block experimental design. Only metham potassium provided 100% control, although both mesotrione and picloram provided significant reduction in plant growth. Tuber numbers were significantly reduced by mesotrione, picloram and clomazone. Similar results were noted for tuber mass, although Mondial appeared to be more sensitive than Sifra for this parameter. The herbicide results were similar to those obtained by other researchers. Although metham potassium was the only truly effective treatment, mesotrione showed great promise for volunteer control. Picloram is not registered for use in cropping systems and cannot be recommended.

Keywords: mesotrione, metham potassium, Mondial, picloram, Sifra