Impact of Different Inoculum Levels of Cereal Cyst Nematode (Heterodera avenae) on the Physiological Traits of Wheat (Triticum aestivum)

This study aimed to examine the effects of various inoculum levels of H. avenae on wheat physiology. The experiments were conducted in the screenhouse at the Department of Nematology, CCSHAU, Hisar, with inoculum levels set at 5, 10, and 15 eggs and juveniles per gram of soil. Observations on physiological parameters were made 30 days post-sowing. It was found that increasing inoculum levels led to significant decreases in total chlorophyll, carotenoid content, chlorophyll fluorescence, photosynthetic rate, transpiration rate, and stomatal conductance. The highest inoculum level showed the most pronounced reductions, with respective decreases of 39.71%, 30.55%, 7.90%, 39.75%, 51.58%, and 64.86%. Highest nematode inoculum level also resulted in the highest reduction in gaseous exchange parameters, biomass and leaf pigments concentrations and maximum increment in nematode population density.