Bulletin of the National Research Centre (Dec 2019)
Differential responses of certain field pea and cowpea cultivars to root-knot nematode, Meloidogyne incognita for commercial release
Abstract
Abstract Background Legumes are considered staple foods for many countries in different areas of the world. Cultivation of nematode-resistant newly introduced field pea and cowpea cultivars is an important, cheap, and economical way to reduce damaging the nematode population that comes from improper use of nematicides and pesticides. Results The cultivars of two examined crops were planted in pots inoculated with second-stage juveniles of M. incognita under screen house conditions. The results proved significant differences (P ≤ 0.05) among the tested cultivars regarding their responses to M. incognita. Host resistance/susceptibility was rated on the basis of potential reproduction index (PRI). Host reaction was based on average percent reduction potentials of plant growth and yield. The combination between host resistance/susceptibility and host reaction rates was used to give clear and accurate determination to these cultivars. According to the later scale, field pea cultivars were grouped into three categories of highly susceptible (Consessa), moderately susceptible (Diacole), and intolerant cultivars (Cerdon, Samantha and 337), while cowpea cultivars were grouped into two categories of highly susceptible (Kafr El-Sheikh) and susceptible cultivars (Dokki and 331). Conclusions None of the tested cowpea and field pea cultivars was found to be resistant or immune to root-knot nematode, M. incognita. Subsequently, plant growth and yield of the tested cultivars seemed to be severely damaged by root-knot nematode that might be attributed to less nutrient uptake by field pea and cowpea roots due to nematode infection. Planting of highly susceptible or susceptible cultivar in progression with resistant cultivars may help in limiting or reducing these defects. This is keeping management processes and production more economical. Further studies are needed to evaluate more cultivars/accessions against root-knot nematode.
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