ABSTRACT
An experiment on the cultivation of Black Psyllium, also known as Tukhm-e-balanga [Lallemantia royleana Benth.] was performed according to a simple randomised block design to determine whether supplemental phosphorus application at 60 days after sowing [d] as foliar spray of 1, 2 and 4 kg p/ha [F [p1], F[p2] and F[p4] or top-dressing of 10 and 20kg p/ha T[p10] and T[p20] could improve the growth, yield and quality of the crop. A uniform basal dose [20 kg/ha, each of nitrogen and potassium was applied at sowing. Phosphorus was applied basally at 40kg p/ha recommended dose] in control 1 [B[p40] + F[w0] and at 20 kg p/ha in the remaining treatments, including control 2 [B[p20]+ F[w], both controls being sprayed with de-jonised water at 60 d. The parameters studied were: root length, fresh weight of root, dry weight of root, shoot length, fresh weight of shoot, dry weight of shoot, number of branches/plant, number of buds/branch at full bloom stage and seed yield, biological yield and swelling factor at harvest. Most vegetative parameters were generally enhanced by B[p20] + F[P2], B[p20] + F[P4] and B[p20]. + T[P10] Yield characters and swelling factor were maximum in treatment B[p20]+ F[P2]and B[p20]+ F[P4].It may, therefore, be concluded that foliar spray of only 2 kg P/ha on plants grown with half the recommended P dose at sowing proved optimum and resulting simultaneously in the economy of phosphatic fertilizer