Non-chemical weed control systems in organically grown spring oilseed rape

Abstract

This study aims to determine the impact of different non-chemical weed control systems on organically grown spring oilseed rape (Brassica napus L.) crop weediness and yield of seeds. Non-chemical weed control systems: 1) thermal (water steam), 2) mechanical (inter-row loosening), and 3) smothering (self-regulation). Thermal (1.5–1.8 times) and mechanical (2.5–6.8 times) weed control systems significantly reduced the number of weed seedlings in spring oilseed rape crop, compared with the weed smothering system. The most effective system of weed control in rape crop was mechanical (efficiency 30.9–75.5 %). Efficiency of thermal weed control system, compared with mechanical, was lower, 28.4–40.0 %. Before rape harvesting in plots where mechanical weed control was applied, compared with plots where weed smothering was used, the number of weeds was significantly 3.2–4.4 times lower, and dry matter mass of weeds was 2.2–3.1 times lower. The yield of rape seeds increased with increasing efficiency of thermal and mechanical weed control. In 2014, the yield of rape seeds depended on number of weed seedlings and dry matter mass of weeds before rape harvesting.

Keywords: spring oilseed rape, weed control systems, weed, yield, organic farming