Journal of Experimental Agriculture International

Lettuce is the hardwood vegetable that presents the greatest increase of consumption in Brazil, and therefore the most important for local horticulture. Because the intensity of cultivation, and the large area planting, some problems have worsened, especially issues related to pathogens such as nematodes of the species Meloidogyne incognita, which penetrate to the root AND CAUSING reduction in productivity. Existing cultivars on the market have more or less able to tolerate the nematodes attack, depending on growing conditions and climate conditions which are subject. In addition to these factors, the actual population of nematodes is a determining factor to harm the yield of lettuce. The cultivars used were Solaris^©, Elba^©, Amanda^©, SRV 2005^©, subjected to two of inoculum  nematode M. incognita, 10,000 eggs / plant and 20,000 eggs / plant, and a control without the presence nematodes. The experimental arrangement used was the randomized block design in a factorial (4 x 3) with 4 replications. Plants were harvested 48 days after planting and evaluated the Fresh weight of shoots (FWS), Number of leaves (NS), Head diameter (HD), Stem diameter (SD), Stem length (SL), Fresh root mass (FRM), - Average number of eggs (ANE), and Reproduction factor (RF). Cultivar SRV 2005 has the potential to be used in areas with the presence of Meloidogyne incognita (race 1), and can be used as a potential source of resistance to the pathogen. The initial innoculation of eggs did not affect the interaction of the genotype with the final concentration of Meloidogyne incognita eggs (Race 1). The initial number of 20,000 eggs promoted a higher average number of eggs at the end of the crop cycle, but the reproduction factor presented a decrease in the final number of eggs with approximately 14,000 units.