The effects of treatments with selected pesticides on viability and vigour of maize (Zea mays) seeds and seedling emergence in the presence of Fusarium graminearum

Abstract

SUMMARYThe quality of seed is dependent on two very broad aspects: how healthy (disease-free) a seed is and its field performance (germination and vigour). The objective of the present study was to evaluate the effect of pesticidal seed treatments of maize (Zea mays L.) on seed germination and vigour, and on greenhouse emergence in the presence of Fusarium graminearum Schw. Maize seeds were treated with four pesticides: Apron® XL (metalaxyl), Thiram (thiram), Celest® XL (fludioxonil, metalaxyl) and Apron® Star 42 WS (thiamethoxam, metalaxyl, difenoconazole). Viability and vigour of the treated seeds were determined. Thereafter, seeds were planted under greenhouse conditions. The control consisted of water-treated seeds. None of the pesticides reduced the standard germination under laboratory conditions and none had any effect on the quantity of leachate (measured as conductivity) or moisture content of the seeds. The different treatments also had no effect on germination or on seedling weight increase among treatments after rapid imbibition and there was no difference in germination among treatments following the cold test. The proportion of diseased plants harvested from F. graminearum inoculated soil was significantly reduced by Apron® Star 42 WS and Celest® XL. The vigour tests indicated that none of the pesticides tested affected the seeds negatively and that plant biomass in the presence of the pathogen, F. graminearum, was increased after the application of the pesticides to the seeds, with the exception of seeds treated with Apron® XL.