-The use of spontaneous species as green manure in the production of vegetables is slowly starting to produce satisfactory results. The purpose of the present study was to evaluate the productive performance of lettuce at different quantities and times of decomposition of dry scarlet starglory (Merremia aegyptia L.) incorporated into the soil. The present study was carried out from October to December 2006 in a vegetable garden of Plant Sciences Department of the Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró-RN¸ Brazil. The experimental design was a randomized complete block with the treatments arranged in a factorial 4 x 4 + 1, with three replications. The treatments consisted of the combination of four dry scarlet starglory amounts incorporated into the soil (2.6; 5.2; 7.8 and 10.4 t ha -1 of dry matter) with four different decomposition times (0; 10; 20 and 30 days before transplanting of lettuce -DBT), plus one additional treatment (80 t ha -1 of cattle manure, a traditional treatment in the lettuce cropping). The lettuce cultivar grown was 'Babá de Verão'. The evaluated characteristics were: height and diameter of plants, number of leaves per plant, fresh and dry mass of the lettuce shoots. The incorporation of dry scarlet starglory into the soil influenced the productive performance of lettuce in a positive way, thereby showing promise for use as a green manure. The highest fresh mass amount of the lettuce (15.33 t ha ) com quatro tempos de decomposição (0; 10; 20 e 30 dias antes do transplantio da alface) mais um tratamento adicional (80 t ha -1 de esterco bovino, tratamento tradicional usado no cultivo dessa hortaliça). A cultivar de alface cultivada foi a Babá de Verão. As características avaliadas foram: altura e diâmetro de plantas, número de folhas por planta, massa fresca e seca da parte aérea da alface. A incorporação da jitirana seca ao solo influenciou de forma positiva no desempenho produtivo da alface, mostrando-se promissora para ser utilizada como adubo. A maior quantidade de massa fresca da alface (15,33 t ha -1