Evaluation of Tomato Culktivar for resistance to wilt disease and their host efficiency to Meloidogyne Incorgnita Infestation
Field and screen house studies were conducted to evaluate the resistance of some tomato cultivars to wilt diseases in Meloidogyne incognita Race 2 naturally infested soil and to test their host efficiency to the nematodes infestation. Five-week old tomato seedlings from each cultivar raised in steam-sterilized soil were transplanted into plots naturally infested with species of plant-parasitic nematodes. The experimental design was a randomized complete block replicated four times. In the screen house trial, five-week old seedlings from each cultivar raised in steam-sterilized soil were transplanted into plastic pots (22.5 cm diameter). Eggs of M. incognita were extracted from pure cultures of the nematodes earlier raised on Celosia argentea L. plant using the chlorox method of extraction. Each seedling was infested with 10,000 eggs of the nematodes. The experiment was laid-out in a completely randomized design with three replications. In the field trials, there were significant incidences of tomato wilt among the tested lines. Three cultivars Tomato-Dalila, Tomato-Akash and Indam-2103 showed tolerance to wilt infection with a range of 9.8 % to 19.7 % seedling loss in 2003 and 2004 respectively. Severities of roots damage caused by nematodes were significantly low in the two field trials. In the screen house evaluation however, none of the cultivars was immune or resistant. The host efficiency test showed that all the tested cultivars were efficient hosts to M. incognita. Growth and yield assessment of the cultivars under field conditions indicated that cultivar F13109 flowered earliest (69.7 days) in 2003 and 72.1 days in 2004 while INDAM-2107 recorded the best luxuriant growth (vigour) in 2004. The highest number of fruit-set per flower cluster was observed in F143 in 2003 and 2004. Cultivar F13019 recorded significantly the highest number of fruits (169.3 and 143.3) while the heaviest weight was observed in AKASH (2.24 kg and 2.7 kg) respectively in both trials. Tomato-Marina recorded statistically the lowest numbers (9.6 and 11.17) and weights (0.23 kg and 0.73 kg) of fruits respectively in both evaluations.
Keywords:Meloidogyne incognita Resistance, Tomato, Wilt disease.
Nigerian Journal of Horticultural Science Vol. 10 2005: pp. 30-37