Field Evaluation of Tomato Genotypes for Resistance to Meloidogyne incognita

The effects of Meloidogyne incognita on growth of tomato genotypes and nematode reproduction were studied in the nematode infested field. The genotypes included were Riogrande, Round-41, Round-27, Round Small-127, PB-47, PB-28 and PB-8. Three week old seedlings were transplanted on raised strips in a randomized complete block design with three replications. At 60 days, plants were uprooted, washed and ranked for root galling and egg mass indices on a 0 to 5 scales. The plant growth responses i.e., foliage length, foliage weight, root length and root weight and nematode reproduction in term of number of galls per root system, gall index, egg masses, egg mass index, eggs per root system, eggs per gram of root and second stage juveniles per 100-cm(3) of soil were recorded. The field experiment revealed that M. incognita was able to induce root galling and reproduced on all the seven tomato genotypes. All the genotypes were found susceptible to M incognita infection however, responses were variable. Tomato cv. PB-8 and PB-28 were susceptible with gall index of 4. While other five genotypes namely Round-41, Riogrande, Round-27, Round Small-127, and PB-47 were highly susceptible having gall indices of 5. The findings of this trial proved that there is no resistant cultivar for growers to recommend.