Effect of arbuscular mycorrhizae and phosphorus on seedling growth of Casuarina equisetifolia

ABSTRACT: Seedling growth and vigour of casuarina [Casuarina equisetifolia (Frost.)] raised in polybags were evalu-ated after inoculating nursery soil mixture with 3 cultures of Arbuscular Mycorrhizae (AM) along with 3 levels of fertilizer phosphorus (0,300 and 500 mg/polybag). AM inoculated seedlings grew faster and healthier than uninoculated seedlings, Among AM cultures, Glomus fasiculatum was found to be efficient. When combined with P at 300 mg/polybag its efficiency was greater and produced robust seedlings with longer root and shoot as well as higher drymatter and P uptake. However, when P was applied at 500 mglpolybag in combination with cultures, AM colonisation appreciably decreased and no improvement in growth of seedlings was observed. Key words: AM fungi, phosphorus, casuraina, seedling growth. Casuarina is one of the most important tree spe-cies suitable for agroforestry in the soils of tropics. It is grown for fuel wood production, land reclamation, sand dune stabilization and as shelter belts, (NAS, 1984). Casuarina seedlings essentially require phospho-rus (P) for its sturdy growth, but mere application of P fertilizer was not much effective for seedlings due to sparse root system. Earlier researchers have documented that the inoculation of AM is beneficial to crops by way of mobilizing nutrients especially P (Lambert an