Dichotomous table for gallers on Nicotiana
by Hans Roskam
1a On roots or root collar => 2
1b ale green, spongy, bladder- or bulging expanded swellings, 5–20 mm long or more; on young plants mainly at stem base, on older ones higher on stem. Ditylenchus dipsaci
1c Stunting of growing points, curling of leaves. Myzus persicae subsp. nicotianae
2a oots with spindle- shaped or nodular swellings. Nicotiana spp.: Meloidogyne hapla
2b Conspicuous cancer-like malformations of various size, mainly on root collar, but also on higher situated stem parts. Nicotiana spp.: Agrobacterium tumefaciens
2c On the root collar, especially of N. glutinosa, less on N. tabacum occur the leafy galls Rhodococcus fascians