Two experiments were carried out at Federal University of Lavras Minas Gerais State, Brazil, from April to September, 2006, aiming to evaluate the lettuce and rocket intercropping system, under organic and mineral fertilization in different spatial arrangements. For each experiment, the experimental design was randomized complete blocks with five treatments and four replicates. The treatments consisted of four spatial arrangements of lettuce (a) and rocket (r), planted in alternate rows 1A: 1R; alternate double rows 2A: 2R; alternate triple rows 3A: 3R, alternate four rows 4A: 4R and lettuce and rocket in sole crop. Evaluations for diameter (lettuce), plant height, number of leaves per plant, leaf yield and leaf dry matter were made in the lettuce and rocket crop. The highest yield of lettuce leaves was registered in the organic farming. The yield of rocket fresh mass, in sole crop was higher than the others although statistically similar to the spatial arrangements 3A: 3R and 4A: 4R for the number of leaves. In organic farming, significant differences between first rocket growth and regrowth were observed in plant height and shoot dry mass, with the highest average of plant height registered in the growth and the highest shoot dry mass in the regrowth. The intercropping systems of lettuce and rocket in the spatial arrangements of 1A: 1R and 3A: 3R had the highest efficiency (LER), ranging from 55 to 63%, respectively, in the organic farming. Biological efficiency increased up to 62 and 70% in these same arrangements, with the regrowth of the rocket in the organic farming. All the associations of the lettuce and rocket as well as their sole crop had better productive performance under the organic fertilization and the regrowth of rocket increased the agronomic efficiency of the intercropping system.
Lactuca sativa; Eruca sativa; competition; agronomic efficiency
