Experiments were conducted over two seasons (1999/ 2000 and 2000/2001) at Canterbury, New Zealand (Lat. 43°38ЈS, Long. 172°30ЈE) to study the effect of time of sowing on soybean (Glycine max (L.) Merrill.) seed yield and yield components. Four cool-tolerant cultivars (Northern Conquest (Group V) and Maypole, Alta and March (Group VII)) were sown at three dates (15 November, 7 and 29 December) in 1999 and two of the cultivars (Northern Conquest and March) were sown at four dates (