Biology and survival of broom corn millet (<i>Panicum miliaceum</i>) seed

The wild type of broom corn millet (Panicum miliaceum) is a serious emerging weed currently prevalent in New Zealand sweet corn (Zea mays) crops This study shows its seed is nearly twice the weight of other common grass weeds and can germinate in the temperature range 1634C with 50 germination at 26C and greatest germination occurring at 31C At 15C it took 8 days for seedlings to emerge but required only 4 days at 25C Seed was able to emerge from depths of up to 170 mm in a range of soils Experiments showed that broom corn millet seed can persist in the soil for longer than 2 years in the field but is killed in silage stack and bales Immersion in stock effluent for up to three months reduced seed germination to less than 40 These characteristics are discussed in relation to herbicide and management control options for this weed