Morphology of tomato plants under nematode attack and salicylic acid application

Root-knot nematodes are the main soil-dwelling phytopathogens that cause severe damages to plants, especially tomato plants. Exogenous application of salicylic acid (SA) can mitigate such pathogenicity. This work aimed to evaluate the growth of tomato plants submitted to Meloidogyne javanica population densities (PD) and application of SA. The experiment was a randomized block design, in an incomplete factorial scheme (central composite design), with five PD (0, 5815, 20000, 34184, and 40,000 eggs per pot) and five SA doses (0.0, 0.29, 1.0, 1.71, and 2.0 mM), with four replicates containing two plants each. Number of leaves, plant height, stem diameter, shoot dry mass, root dry mass and total dry mass, Dickson's quality index, leaf area, specific leaf area, specific leaf weight, root volume, absolute and relative growth rates for plant height, number of eggs, number of galls, and nematode reproduction factor were evaluated at 50 days after soil inoculation (DAI). Results showed the application of 0.97, 2.0, and 0.88 mM SA increased, respectively, the RGR, SLA and SLW. On the other hand, 0.91 and 0.93 mM SA decreased, respectively, the number of eggs and reproduction factor of nematodes. Also, M. javanica did not affect the growth of tomato plants until 50 DAI.