Effects of some chemical treatments on standard germination, field emergence and vigour in hybrid maize seeds

The main aim of this experiment was to investigate the possible effects of some active ingredients and their combinations, commonly adopted for maize seed treatment in Italian agriculture, on seed germination, vigour (cold test) and field emergence. Among the seed treatments, fludioxonil + metalaxyl-M (non-systemic fungicides) with the insecticide mixture tefluthrin (belonging to the pyrethroids class) and methiocarb (belonging to the carbamates), negatively affected field emergence of hybrid maize seeds under favourable and restricted temperature conditions, and the cold test results. The two insecticides showed a significant synergistic detrimental action compared with the effects of each active ingredient. These results confirm the need for precaution when using new formulations with an insecticide mixture. The cold test was confirmed as an excellent test able to highlight a possible loss of seed vigour, which usually is not evident with a standard germination test, and to estimate seed performance in the field, especially under cold temperatures, as often happens when adopting modern crop management techniques like sod seeding and early sowing at the end of winter.