Effect of Meloidogyne incognita and Macrophomina phaseolina alone and in combination in different types of soil on the resistance/susceptibility of cultivars of Okra

Effect of Meloidogyne incognita and Macrophomina phaseolina was observed singly, and together in three soil types on plant growth parameters of okra Abelmoschus esculentus (L.) Moench cultivars Arka, Hybrid, Rohini, Nirmal and Abhay. Plant growth was greater in loam soil followed by 20% fly ash soil, and least in 20% sand mix soil. Plant growth (shoot dry weight), was reduced in plants inoculated with any test pathogen. Inoculation of both pathogens together caused a greater reduction of plant growth than their individual inoculation in all the 5 cultivars. Cultivars Arka, was found moderately resistant (MR), Hybrid, Rohini and Nirmal were Tolerant, and Abhay was susceptible to M. incognita in types of soil tested. Similarly, cultivars Arka, Rohini and Nirmal were MR, Hybrid was highly susceptible (HS) and Abhay was tolerant to M. phaseolina. However, Arka, Rohini and Nirmal were rated as susceptible while hybrid and Abhay were HS against M. incognita plus M. phaseolina . Highest galling and nematode population were observed in Abhay and least in Arka. Galling and nematode multiplication was high in 20% sand mix soil followed by loam soil and least in 20% fly ash amended soil. Root rot disease index also varied in different okra cultivars.