Prevalence of plant parasitic nematodes vary with crop cultivars/clones

Abstract

The prevalence of plant parasitic nematodes on four horticultural crops viz. rose,Hypericum, snap bean and enset was assessed in 2016. Random sampling was used tocollect soil samples using auger. Nematodes were recovered from 100 ml soil per sampleusing a modified Baermann tray technique, identified and enumerated from 1 mlnematode suspension. All the four crop types were found infested with root knotnematode at varying population among cultivars/clones. M. hapla infecting rosesoccurred on citron cultivar at significantly higher (P> 0.05) population density of 1481 J2while the lowest population density was on Olympia (668 J2) per 100 ml soil. Hypericumcultivars were found infected by M. javanica at highest density of 5020 J2 100 ml -1 soils onCalypso. On the other hand, snap bean were found infected by in addition to M.incognita that occurred most on Faraday (6485 J2 100 ml -1 soil), by Helicotylenchus,Pratylenchus, Rotylenchulus, Scutellonema and Tylenchorhynchus. Greater densities ofPratylenchus and Rotylenchulus were supported by this cultivar. Compared to the othercrops, enset generally supported lower densities of Meloidogyne spp. of 490 and 385 J2 onclone Wagu and Astera, respectively. Hoplolaimus, Mesocriconema, Pratylenchus,Radopholus, Scutellonema, Trichodorus, Trophurus and Tylenchorhynchus were also commondepending on enset clone. Based on the distribution and population density, Meloidogynespp. were most important nematodes on all the crops. Depending on the cultivar, heavyto light root galling was observed on rose, snap bean and hypercum. Snap bean cultivarswere most attacked and plants showed yellowish foliage and patchy stand in the field.Differences in nematode population density for all the nematode genera found amongcultivars/clones might provide an opportunity to explore future potentials for resistanceor tolerance characteristics that can be used to combat their damage on yield.