Possibilities of mechanical post-emergence weed control in sugar beet

Abstract

During a period of four years, 1986–1989, a number of field experiments on post-emergence weed control in sugar beet was carried out. The experiments are components of five weed control systems: chemical; integrated; integrated including ridging; mechanical; mechanical with plants in squares. The effect of the planting system, plant distribution and of the weed control system on weed growth and crop yield was investigated. Integrated weed control (+ ridging) was relatively unsatisfactory from the perspective of weed density, but mostly without serious yield losses with regard to chemical weed control. Mechanical weed control in a row crop proved to be inadequate, because of intra-row weed growth. With beet in square distribution, the mechanically treated area increased from about 70% to about 90% of the arable surface. This resulted in the lowest density and biomass of weeds at the closing of the crop and an extra yield of transplanted beet in squares over drilled beet in rows of nearly 10 t ha −1.