Effect of Meloidogyne incognita on bio-chemical changes in leaves of Mentha arvensis

Meloidogyne incognita @0, 10, 100, 1000, 10,000J₂/plant/per pot was inoculated to study the impact on bio-chemical changes in Mentha arvensis under greenhouse conditions. Decrease in reducing sugar, carbohydrate and phenol in mentha leave was observed at all inoculum levels over check. The decrease was progressive with increase in nematode inoculum levels. Significant decrease in above parameters was observed on 1000 and 10,000 J₂/pot/. Meloidogyne incognita inoculum @1000J₂//pot and above significantly affected the quality of mint oil. It significantly reduced the menthol per-cent in mint oil, which is the basis of price fixation in market. Other constituent viz., menthone, isomenthol, methyl acetate and neo-menthol of mint oil were also affected. Significant reduction in all constituents of mint oil was observed on highest nematode inoculum level.