Abstract

This report begins with a review on weed biology and how weeds influence the yield of carrots and bulb onions. There is also a discussion about different methods for weed control in row crops, different brush weeders in general and the Swedish "Thermec B" brush weeder in particular. Field experiments were performed with Thermec brush weeder in order to investigate the weed control effect. Pilot. experiments in carrots and bulb onions showed that it was possible to control weeds not only between the rows but also in the row. One experiment showed that it was possible to remove 73% of the weeds with a working intensity of 2.6. Intensity is defined as the ratio between the peripherial speed of the brushes and the driving speed. The experiments with an intensity of 2.6, showed that intra-row brush weeding did not affect the yield of carrots, bulb onions and sugarbeets, when these crops were 15 cm or higher.