Effects of long-term reduced tillage on weed infestation of pea (Pisum sativum L.)

Abstract

The study evaluated weed infestation of pea (Pisum sativum L.) cultivated under conditions of conventional (CT), reduced (RT) and herbicide tillage (HT). It demonstrated the highest weed density per m² in plots with the herbicide (HT) and reduced (RT) systems and significantly lower weed infestation in plots cultivated in the conventional system (CT). In addition, more weeds occurred at the third leaf stage (13/14 in BBCH scale) than at the pod development stage (73/74 BBCH) of pea. The highest biomass was produced by weeds in the herbicide system (HT), a lower one – in the reduced system (RT), and the lowest one – in the conventional system (CT). The air-dry weight of weeds depended also on pea development stage. At the pod development stage (73/74 BBCH), the air-dry weight of weeds was significantly higher than at the third leaf stage (13/14 BBCH). The tillage system was also observed to influence the species composition of weeds. This trait was also affected by the period of weed infestation assessment. At the third leaf stage of pea (13/14 BBCH), there occurred 26 weed species, including 24 annual ones. The most abundant species included: Chenopodium album L., Stellaria media (L.) Vill., Capsella bursa-pastoris (L.) Med., Matricaria inodora L., Thlaspi arvense L., and Fallopia convolvulus (L.) A. Löve. At the pod development stage (73/74 BBCH), the pea crop was colonized by 24 weed species, including 3 perennial ones. At this stage the predominant species included: Avena fatua L., Amaranthus retroflexus L., Papaver rhoeas L., Echinochloa crus-galli (L.) P.B., Matricaria inodora L., and Galeopsis tetrahit L.