RELATIONSHIP BETWEEN SEED VIGOR AND YIELD OF WHITE BEANS (PHASEOLUS-VULGARIS L)

Conflicting reports have been published concerning the relationship be tween seed vigour and yield of the resulting crop. Studies were conduc ted in 1987 and 1988 at Elora, Ontario, to determine the effect of sow ing high and low vigour white bean (Phaseolus vulgaris L.) seed lots o n field emergence, plant stand and seed yield. Eight white bean seed l ots of Seafarer and Ex Rico 23 were obtained from a commercial seed su pplier in Ontario and classified into high or low vigour based on resu lts of laboratory tests before sowing in the field. High vigour seed l ots emerged and established significantly better than the low vigour s eed lots in 1988 when unfavourable field and environmental conditions prevailed early in the season. Sowing high vigour seeds in 1988 result ed in 5% yield increase compared to low vigour seed lots. However, in 1987, ideal field conditions occurred and no effect of seed vigour was detected. There was no relationship between yield and total number of gaps 15 cm to 30 cm in length because of the ability of white beans t o compensate for reduced stands. This ability declines with an increas e in gap size. Seed lot differences were noted for all variables, but most were attributed to variety differences and/or vigour differences within varieties. No yield advantage can be associated with using high vigour seed lots when weather and soil conditions are favourable. How ever, favourable conditions are an uncertainty and if is therefore imp ortant to use high vigour white bean seed lots to obtain optimum yield s.