Yield and weed abundance in early- and late-sown field pea and lentil

Field peas (Pisum sativum L.) and lentils (Lens culinaris Medik.) are high protein food crops for potential use in organic rotations. We determined the effects of cultivar selection, delayed sowing, and weed removal on yield of spring-planted field peas and lentils grown using organic methods. In 2009 and 2010, at three southern Minnesota locations, two lentil cultivars (Crimson and Pennell) and four yellow field pea cultivars (DS Admiral, Commander, Yellow, and Miami) were planted on three planting dates (18 April, 28 April, and 10 May) and grown with and without weed control. Yields of Crimson lentil were 66% higher on average than those of Pennell lentil. Pea cultivars had similar yields. Yields of peas planted on 18 April were 23 and 71% greater than yields for peas planted on 28 April, and 10 May, respectively. Yields of lentils at the early date were 50 and 120% greater than those at the middle and late dates, respectively. Weed removal increased pea yields by an average of 63% and lentil yields by an average of 87%. Both weeded and unweeded pea and lentil yields were higher with early planting. Delayed planting was ineffective in reducing weed biomass. Field pea reliably produced yields sufficient to offset production costs in both low-price commodity and high-price direct marketing scenarios. Lentil yields did not consistently exceed economic break-even levels in most environments. Field pea is a profitable crop for organic systems when early planted and when weeds are controlled.