Effect of tillage system on the structure of weed infestation of winter wheat

Andrzej Woźniak

doi:10.5424/sjar/2018164-12531

Abstract

The study aimed to evaluate the structure of weed infestation of winter wheat grown in different weeding systems: conventional tillage (CT), reduced tillage (RT), and herbicide treatment (HT). In CT system, shallow ploughing and pre-sow ploughing were conducted after the harvest of the previous crop. In RT system, shallow ploughing was replaced by cultivator tillage, whereas pre-sow ploughing by a tillage set. In HT system, shallow ploughing was replaced by spraying with glyphosate and pre-sow ploughing by cultivator tillage. At the tillering stage (22-23 in BBCH scale), species composition and number of weeds/m2 were determined with the botanical-gravimetric method, whereas at the stage of waxy maturity of wheat (82-83 BBCH) analyses were conducted for species composition as well as density, air-dry weight, and weed distribution in crop levels. The Shannon-Wiener’s diversity index (H’) and degrees of phytosociological constancy (S) of weeds were determined as well. The study showed that more weeds occurred in RT and HT systems than in the CT system and they produced higher biomass in RT than in CT and HT systems. The tillage system affected weed distribution in crop levels. In CT system, the highest weed density was identified in the ground and lower levels, whereas in RT and HT systems in the ground and middle levels. Values of the species diversity index (H’) indicate a similar diversity of weed species composition between weeding systems and more diverse between study years.

Highlights

The tillage system and improvement of agrotechnical measures have a significant effect upon the condition and extent of crops infestation with weeds (Gruber et al, 2012; Nichols et al, 2015; Woźniak & Soroka, 2017)
The air-dry weight of weeds determined at the waxy maturity stage of wheat (82-83 BBCH) was higher by 32.1% in the reduced tillage (RT) than in the conventional tillage (CT) system and by 25.3% than in the herbicide treatment (HT) system (Table 2)
At the tillering stage of wheat (22-23 BBCH), from 6 to 12 species were identified in CT plots, the most abundant of which were Consolida regalis, Veronica persica, Galium aparine, and Lamium amplexicaule

Summary

Introduction

The tillage system and improvement of agrotechnical measures have a significant effect upon the condition and extent of crops infestation with weeds (Gruber et al, 2012; Nichols et al, 2015; Woźniak & Soroka, 2017). During mechanical cultivation, weed seeds with a short resting period are transferred from the topsoil into deeper soil layers, from where only few are capable of sprouting. It results in a depletion of the seed bank in the soil and, in lesser crop infestation with weeds (Riemens et al, 2007; Gruber & Claupein, 2009). As shown by Woźniak & Soroka (2015a), the highest number of weed species in pea crops occurred in the reduced tillage system with the use of a tillage unit consisting of a cultivator and a roller, whereas the lowest number in the system of direct sowing. Herbicides used in the conservation and stubble systems eliminate perennial species and effectively reduce infestation with short-

Methods

Results

Conclusion