The influence of tillage and chemical plant protection on weed infestation of winter spelt wheat cultivars (Triticum aestivum ssp. spelta) growing in continuous crop

The aim of the studies carried out over the period 2009–2011 on mixed medium heavy rendzina was to evaluate the weed infestation of winter cultivars of spelt wheat (‘Ceralio’, ‘Ostro’, ‘Schwabenkorn’ and ‘Spelt I.N.Z.’) depending on the tillage system (conventional and reduced) and chemical plant protection (Mustang 306 SE, Attribut 70 WG, Alert 375 SC, Stabilan 750 SL). Over a three-year study period, the highest dry weight of weeds was found in the crop of cv. ‘Spelt I.N.Z.’, whereas the level of weed infestation for the other cultivars was similar. Replacing ploughing with cultivating resulted in an increase in the numbers of Apera spica-venti, Echinochloa crus-galli, Matricaria maritima and Papaver rhoeas. As a result, the total number of weeds increased by 50.1% compared to conventional tillage, while their dry weight by 17.4% after the use of cultivator instead the plough. The dry weight of weeds decreased nearly 5 times under the applied crop protection treatments, but the species composition of weed communities did not change significantly compared to the control treatment without chemical protection