The effect of non-chemical weed control methods on winter oilseed rape crop weediness and productivity

Abstract

The area of orgnanically grown oilseed rape in the world is about 93,000 ha, in Lithuania about 3,962 ha (in 2017). The yield of oilseed rape in organic farming is low and variable because oi pests, weeds and diseases spreading. Weed control in winter rape crops is important especialy a: early stages of development. The competitive ability of a rape crop for weed smothering is ofter used in organically grown oilseed rape, and usage of mechanical weed control is limited. Therma weed control (steaming) is one of effective weed control methods in organic farming system. This study aims to investigate the effect of non-chemical weed control methods on wintei oilseed rape (Brassica napus L. ssp. oleifera biennis Metzg.) crop weediness and productivity. A field experiment was performed in 2014—2017 at the Experimental Station of Aleksandra; Stulginskis University (54°53' N, 23°50' E). The soil at the experimental site was classified as Calc(ar)i-Endohypogleyic Luvisol (Drainic) according to the WRB 2014. The main plot treatment; involved plant bio-activators as follows: 1) without application and 2) with application. The subploi treatments included a combination of non-chemical weed control measures, including the following treatments: 1) thermal (water steam; row spacing of 48 cm) - TWC; 2) mechanical (inter-row loosening; row spacing of 48 cm) - MWC and 3) smothering (self-regulation; row spacing of 12 cm - SMT. Annual dicotyledonous weeds prevailed in winter oilseed rape crop: Tripleurospermun perforatum, Stellaria media, Capsella bursa-pastoris and of monocotyledonous Poa annua. Weed contro methods and plant-bioactivators had no significant effect on weed density in winter oilseed crof before harvest. The lowest weed dry mass was in plots were MWC method was used. The strongei effect of TWC method was estimated in plots with plant bio-activators. ... [et al.]