Nematodes

Two types of nematodes generate malformation on tobacco roots: cyst nematodes (Globodera spp., and gall nematodes, “root-knot nematodes” (Meloidogyne spp.,)
 
- Globodera spp. 
 
Several subspecies of Globodera have been reported on tobacco in the world. In France, only Globodera tabacum sensu strictu seems to be present. This cyst nematode is mainly localized in some fields of the Southwest of France. Its presence on the roots is evident  by the numerous cysts scattered over young or old  roots (figures 1 to 3). The cysts  vary in size depending on the species. In all cases, affected tobacco plants have reduced growth.

Figure 1	Figure 2	Figure 3

- Meloidogyne spp. 
 
Root-knot nematodes are not a limiting factor for tobacco production in France, regardless the cultivated type. Again, the largest incidence is mostly found in the Southwest and more precisely in the Lot-et-Garonne region. This is certainly due to the fact that this region also produces many vegetable crops. The damage caused by nematodes, root galls and swellings (figures 4-7), are very characteristic and easily identified. Several species have been reported on tobacco. In France, we are essentially dealing with Meloidogyne incognita and Meloidogyne arenaria.

Figure 4	Figure 5	Figure 6	Figure 7

 
For detailed  information regarding these two types of nematodes, we recommend that you see the following fact sheets: Some characteristics of root nematodes , Globodera tabacum and Meloidogyne spp..