Interplanted Barley and Rye in Carrots and Onions

Abstract

Carrots (Daucus carota L.) or onions (Allium cepa L.) were interplanted with barley (Hordeum vulgare L.) or rye (Secale cereale L.) seeded at 0, 0.5, 1.0, or 2.0 bushels/acre (0, 43.5, 87, and 174 liters-ha-i). Barley was killed at heights of 4, 8, 12, or 16 inches (10, 20, 30, or 40 cm), and rye was killed at 4, 6, 7, or 8 inches with a postemergence graminicide. Barley and rye killed at 4 inches did not reduce onion yield. If barley exceeded 8 inches and rye exceeded 7 inches when killed, onion yields were reduced. Carrot yield was reduced only by 2 bushels of barley killed at 16 inches. One bushel of barley per acre killed at 4 inches appeared to be optimal in giving good soil protection and minimal crop competition.