The potential of lentil (Lens culinaris) as a grain legume crop in the UK:: an assessment based on a crop growth model

A crop growth model developed in Canterbury, New Zealand was used to assess the potential of lentil (Lens culinaris) as a grain legume crop in the UK. The model was validated using five sowing dates at Durham (54.77degreesN, 1.58degreesW) in 1999. Predicted time to flowering was within 7 days of actual tune to flowering and predicted seed yields were within 9% of actual yields. Actual yields ranged from 1.40 to 1.65 t ha(-1). Seed was of high quality. The model was used to predict rate of development and yields of spring and autumn sown lentils at eight sites along a transect from NW Scotland (Stornoway, 58.22degreesN, 6.32degreesW) to SE England (East Malling, 51.28degreesN, 0.45degreesE) chosen to encompass important environmental gradients in the UK. In general, for a I May sowing with 150 or 250 mm plant available water (PAW) and a 1 October sowing with 150 mm PAW, predicted mean values over the period 1987-95 for maximum crop growth rate, maximum leaf area index, radiation intercepted, total dry matter produced and seed yield were closely positively related to monthly mean values for mean daily air temperature and increased along the transect from NW to SE UK. Time to flowering generally decreased along the transect from NW to SE UK ranging from 28 June to 9 July and from 20 May to 14 June with the May and October sowings respectively. For the I May sowing with 250 mm PAW, predicted mean seed yield ranged from 1.00 to 1.90 t ha(-1). For all sites, yield was very stable over the 9 yr period. For the 1 May sowing with 150 mm PAW, predicted mean seed yield ranged from 0.97-1.23 t ha(-1). Yields for the four more southerly sites were more variable at the lower PAW and, in exceptionally dry years, were substantially lower than average. For these sites, autumn sowing increased seed yields in exceptionally dry years and gave similar or greater mean seed yields to spring sowing with 250 mm PAW. For East Malling, predicted yields for autumn sowing were on average 2.78 t ha(-1). Also, for Stornoway, because of its relatively high overwinter temperatures, the model predicted substantial increases in yield with autumn sowing. It is concluded that lentil has considerable potential as a grain legume crop in the UK.