Pea (Pisum sativum L) is a valuable crop all over the world, is also known as “Matar”. It
belongs to family Leguminosae and sub family Papilionaceae. It’s affected by various
Fungal, Bacterial and Viral diseases. Powdery mildew of pea is one of the major diseases of
pea incited by Erysiphe polygoni DC. Major symptoms of powdery mildew disease are the
presence of white floury patches appeared on the leaves as well as stems, tendrils, pods and in
the severe condition its cover whole plant parts except root region and finally plant become
older and later stage of the crop whole plant become comparatively greyish brown and the
infected parts convey dull appearance. In extreme condition infected pods and leaves fall
down from the plant. An experiment was conducted at farm of SKNCOA, Jobner during Rabi
season 2021. Plants respond to external stimuli by altering metabolic pathways, resulting in a
cascade of different interrelated changes in biochemical processes. The incidence of powdery
mildew in pea induces change in phenol, peroxidase and reducing sugar. Powdery mildew
resistant and susceptible pea genotypes respond differentially to these traits. Powdery mildew
resistant genotypes had comparatively less concentration of reducing sugar and high
concentration of phenol and peroxidase before and after infection. All the traits being
significantly correlated with disease severity can be an important component of an effective
powdery mildew screening procedure in pea.