The 2009 ASHS Annual Conference

An experiment with greenhouse grown grafted tomatoes (Solanum esculentum) on commercial rootstocks was conducted to evaluate performance of scions under natural RKN (Meloidogyne sp) pressure.  The rootstocks tested included the varieties’ Aloha’, ‘Aegis’, ‘Anchor-T’, ‘Armada’, ‘B.B.’, ‘Camel’, ‘Survivor’,‘Beaufort’, ‘Multifort’  and ‘TX301’.  The scion variety was ‘RealEZA’ a small fruited variety.  Plants were grown under greenhouse conditions in untreated thoroughly mixed soil from a vegetable production site with a history of RKN infestations.  The plants were placed in a completely randomized design in 12 L pots with low volume irrigation.  Included in the rootstock treatments were self-grafted scion controls.  Nematode damage was assessed using the Zeck scale  with 0 no visible infestation and 10 as maximum infestation with severe galling and little or no root system.

Root damage from nematode feeding was greatest on the self-grafted ‘RealEZA’ scion with 100% of the plants rated between a 6 and 8.   Several rootstocks showed little or no visual infestations in the form of galls including ‘Armada’, ‘Camel’, and ‘BB’ with a 0 rating.  The next group was essentially free of damage with a rating of 0-1 and included ‘Ageis’, ‘Aloha’ and ‘Anchor T’.  Rootstocks with the greatest infestation were ‘TX301’ at 2-3, 'Beaufort' with a 4-5 rating and ‘Multifort’ with a mixed rating of 5-6 for two plants and 0 for the remaining three individuals in this group.  Overall the self grafted control faired the worst with rating of 7-8 showing extensive damage on the root system.  No shoots originating (suckers) from the rootstocks was observed during the duration of these experiments which was not the case in the field where regrowth was prominent in several varieties.