Electrical weed control in sugar beet - A comparison of pre-emergence methods

Abstract

Competition between sugar beet and weeds can result in tremendous yield losses, which were confined by the use of chemical herbicides in the past. In view to address soil conservation, a reducing number of available chemical herbicides, the need to prevent weed resistances and exacting food security standards, new management approaches must be implemented into modern crop protection. In this context, electrical weed control for pre-emergence in sugar beet, cultivated in mulch sowing to prevent erosion and to improve water infiltration after heavy rainfall, was integrated in chemical and mechanical weed control strategies. A randomized complete block field trial design with three times replicated plots and eight variants was applied, whereby individual plots (100 m length in total) were separated in 50 m, with and without glyphosate as pre-sowing application. The Zasso Electroherb™ was applied with 3 and 5 km h‑1 speed and 72 kW nominal electrical power in a 3 m area application.

Weed infestation after the pre-emergence weed control, mainly volunteer grain and dicotyledonous weed plants, with glyphosate averaged densities of 5 to 23 plants 10 m^-2, whereas without glyphosate application 5 to 97 plants 10 m^-2 were counted, respectively. Weed control efficiency indicated that the weed community was controlled best by Electroherb™, leaving in the plots without glyphosate application significantly lower weed numbers (of 5 to 11 plants 10 m^-2) behind. Mechanical harrowing on the other side showed here minor efficiency in reducing the volunteer grain weed; averaging weed densities of 72 plants 10 m^-2. Results on sugar beet yields and quality are pending but will be included in the data set for comprehensive conclusions. Our results indicate that the integration of electrical weed control methods into existing strategies can reduce the use of synthetic-chemical herbicides and can also make a significant contribution to the prevention of ongoing and future herbicide resistances.