Three intercrops of onion (cv. Alfa Tropical) and lettuce (cv. Regina 2000) were compared, varying the time intervals between transplants of each one in the field. The experiment was made in a complete randomized block design with the treatments (replicated six times): monocrops of onion and of lettuce, and intercrops of the two vegetables keeping the same onion spacing arrangement, with lettuce transplanted on the same day, 15 days, and 30 days after onion. Lettuce seedlings were placed between onion rows in an alternating manner, thus corresponding to half of its monocrop population density. Except for the last treatment (lettuce 30 days after onion planting) the intercropping system was advantageous in terms of increased income by cultivated area unit. Introducing lettuce into the system did not decrease onion yield in marketable bulbs. In addition, lettuce growth was comparable to that of its monocrop. The land equivalent ratio values confirmed the viability of intercropping onion and lettuce. Besides the adequate agronomic performance, the system leads to more efficiency of inputs and hand labor utilization under the organic management adopted.
Allium cepa; Lactuca sativa; organic farming
