Investigation of efficiency of management methods against Mi-1 virulent root-knot nematodes in protected tomato growing

Tomato is one of the most important vegetables grown through worldwide. Root-knot nematodes (Meloidogyne spp.) cause seriously yield losses in tomato. Therefore, different management methods such as solarisation, chemicals and resistant varieties are used against root-knot nematodes. However, the use of tomato varieties carrying Mi-1 gene are restricted by Mi-1 virulent root-knot nematode populations. In the present study, efficiencies of soil solarisation, heterozygous and homozygous resistant tomato varieties and Flocter WP 5 + Velum SC 400 preparats were examined against these nematodes in greenhouse infected with populations of Mi-1 virulent M. incognita. Primarily, soil solarisation was carried out from June to August for six weeks in 2015. After that; susceptible, heterozygous and homozygous resistant tomato seedlings were planted in the soil. Greenhouse was divided into three fields including two chemical + biological applications and one control after seedling planting. 1st field, Flocter WP 5 + Velum SC 400 were applied just before and after planting. 2nd field, Flocter WP 5 + Velum SC 400 were performed to soil when the population of second-stage juvenile started to increase in soil. 3rd field (control field), no application was carried out. Soil samples were periodically taken every 10 days (27 times) from 24.08.2015 to 31.05.2016 for monitoring population of Mi-1 virulent M. incognita second-stage juvenile. Second-stage juveniles from these samples were obtained and counted under microscope. The plants were harvested on 16.04.2016 and on 31.05.2016, respectively. Then, gall indexes of plant roots were evaluated. Also, efficiencies of applications on yield of tomato varieties were performed. Second-stage juveniles were detected in the soil two months after the solarisation (24.10.2015). All applications were separately evaluated among each other. Density curves of second-stage juvenile population of three tomato varieties were statistically not different from each other. But, when comparing the fields, the lowest second-stage juvenile population density curves were detected in the 2nd field, after that 1st field and the highest second-stage juvenile population density curve was detected in the 3rd field during growing season. Second-stage juvenile population densities in soil were up and down though winter because of low soil temperature. However, second-stage juvenile population densities constantly increased in every sampling from March. Gall indexes on roots of susceptible, heterozygous and homozygous resistant tomato varieties were evaluated in two separate harvest periods. Gall indexes on plant roots were not different among susceptible, homozygous resistant and heterozygous resistant tomatoes planted in the same field. But, Flocter WP 5 + Velum SC 400 which were applied in different periods decreased galls on roots compared to plants in the control field. In the first harvest time, there wasn't a difference between the 1st and the 2nd fields. But in the second harvest, galls on root of plants in the 2nd field were lower than plants in the 1st field. Since tomato varieties used in the experiment were different, yields were separately evaluated for every variety. The yields of tomato varieties planted in the 1st and 2nd fields were higher than the 3rd field. Yields of susceptible and heterozygous resistant tomato varieties planted in the 2nd field were higher than the 1st field. But, yields of homozygous resistant varieties grown in the 1st and 2nd fields were not statistically different from each other. Recently, Mi-1 virulent populations have increased in tomato growing fields. Therefore, our findings would present new information for management practices against the populations.