Root Knot Nematode
I want to determine the initial population of root-knot nematode (J2) in the infected farm or produced tomato greenhouse before culture. Because I want to award the grower before that they start the culture. of course I have tried to extract the J2 from the mentioned soil trough both of tray and centrifugal methods, but I could not find any J2 in the soil, however I am sure the field is infected and I saw the symptoms on the roots and J2 in the soil in two last years. Kind Regards Leila
Outside United States
It can be difficult to isolate root-knot nematodes from soil without a host. The nematodes may be surviving as eggs or in a state of anhydrobiosis waiting for the right environment to continue their life cycle. Although it takes more time you may need to put some soil samples into pots and plant some tomato seeds or transplant a non infested tomato plant into the pots. Grow plants at temperatures of 20-28C for about one month, and then remove the root system and examine it for galls. At this stage, the galls (if present) will be small but their occurrence will indicate the presence of root-knot nematode. You may also want to extract the roots by cutting them into 1-2cm pieces and shaking them in 0.5% NaOCl for 2-3 min before washing the suspension through 250 um sieve nested over a 25 um sieve. You can then count the number of eggs and let the eggs hatch to ensure you have isolated root-knot nematodes.
Dear Carla Thanks a lot for your response, I want to determine the initial population to calculate the growth rate (final population / initial population). If I use the population after one month, I can not calculate the Growth Rate. Do you have any suggestion? All the Best