Abstract:
Snap beans are an economically important commodity grain legume produced in Ethiopia for
food security and to incur foreign currency. However, the production of this crop particularly
in the rift valley of Ethiopia is impaired by plant parasitic nematodes. The current study aimed
at evaluating the reaction of snap bean cultivars those are in the pipe line BC4.4 and Plati, and
cultivars those have been in production Dwarf bean Sony, Dwarf bean Faraday, Serengeti and
Amy were included in the study. Pot experiment was carried out under greenhouse condition
in complete randomized design (CRD) with five replications and one level of nematode
population density. Each plant was inoculated with 1000 second stage juveniles (J2)
previously maintained on tomato plants while uninfected plants served as a control. Eight
weeks after infection, pod number, pod weight, root fresh weight, shoot fresh weight, number
of nematodes per 100gram of soil, number of nematodes per plant and the multiplication rate
of the nematode were taken. All the tested cultivars reacted differently and their yield and
yield components also significantly (P<0.05) different between the cultivars. High root fresh
weight (10.7g) recorded from the control of Dwarf Sony and shoot fresh weight (26.5g)
performed by infected Dwarf Sony and both lower pod number (3) and pod weight (3.14g)
recorded for cultivar BC4.4. The multiplication rate of nematode population for all evaluated
cultivars in Pf/Pi > 1 found to be susceptible for Meloidogyne incognita. Even though the
values of the reproduction factor were numerically different, all the cultivars grouped under
excellent host range. Highest yield gained by Amy and Dwarf bean Faraday under high
nematode reproduction while the least yield gained by cultivar BC4.4. So, using different
initial population density and other additional available cultivars would help to determining
threshold level of the nematode and it will be the future line of work.
