The effect of herbicides on Chenopodium album L. phenology in fodder beet, spring wheat and faba bean crops

Abstract

The objective of the study was to determine the time of occurrence of the emergence, budding, fruiting and seed shedding stages, as well as the degree of advancement of the white goosefoot fruiting and diaspores shedding stages in fodder beet, spring wheat and faba bean crops under mechanical and chemical weed control. Phenological observations were conducted in the years 2000-2002 at 10-day intervals, starting from the day of crop sowing on alluvial soil made of light loam. Chemically weed controlled objects were treated with herbicides: fodder beet - lenacil 80%; spring wheat - MCPA 30% + dicamba 4%; faba bean - linuron 50%. It was proven that the times of occurrence and the scale of the studied phenological stages of white goosefoot depended on the crop species, the in-crop weed control method and the pattern of weather conditions in the study years. White goosefoot had the most favourable conditions of growth in the fodder beet crop. The herbicides in the fodder beet and faba bean crops delayed the emergence and the time of occurrence of successive white goosefoot growth stages. These agents also decreased the degree of diaspores shedding by the weed species studied. The most white goosefoot specimens shed fruits on the mechanically weed controlled plots. The diaspores dissemination was promoted by a warm and moist growing season.