Two experiments were conducted in newly reclaimed soil for two successive winter seasons during 2014/2015 and 2015/2016 at El-Nobaria region, Beheira, Egypt on two peas cultivars, i. e. Little Marvel (LM) and Master B (MB). The purpose of this study is to improve the efficiency of biological seed treatments such as bio-priming and seed coating with T. harzianum in control of root rot disease and improve vegetative growth of pea plants under field conditions. In this investigation four levels of phosphorus were used, i.e. 0, 25, 50 and 75 kg P₂O₅ per fed. and combined with four biological seed treatments, i.e. untreated seeds (control); treated seeds with bio-priming, priming and coated by T. harzianum. Pea root rot disease incidence was recorded after 30 and 60 days of sowing. Results showed that the highest vegetative growth characters, total green pods yield and good quality were obtained by plants of Master P (MB) cultivar compared to Little Marvel (LM). The highest values of previous characters were recorded by plants which received 50 kg P₂O₅ / fed compared with other levels. Phosphorus fertilizer levels at 50 and 75 units/ fed were highly effective then 25 units/ feddan in decreasing the root rot % infection and reduction in the incidence of root rot of pea plants. Recommend by using pea seeds of cv. Master B in cultivation and using bio-primed seeds with bio-control agents like T. harzianum or T. viride or T. asperellum should be utilized for managing seed borne pathogens and fertilizing pea plants by adding mineral phosphorus fertilizer.