Optimization of secondary hardening process of banana plantlets (<i style="">Musa paradisiaca </i>L<i style="">.</i> var. grand nain)

Abstract

In view of significance of well hardened planting material for ensuring highest percentage survival upon transplantation of tissue culture derived plants from shade house (secondary hardening) to farm, studies were undertaken to optimize (i) material for plantlet container, (ii) container size, (iii) potting medium, (iv) use of <i style="">Azotobacter </i>(for nitrogen fixation), <i style="">Aspergillus </i>(for phosphate solubilization) and Vesicular Arbuscular Mycorrhizae (VAM) like <i style="">G. intraradices</i> (for growth promotion)<i style="">, </i>(v) spray of organic extracts and (vi) spacing of plantlets in shade house. These studies have revealed that (a) for the time being, there is no substitute to polybags due to susceptibility of jute bags for decay, (b) optimum size of polybag is 20´16 cm (H´W), (c) soil:press mud cake (3:1) is cost-effective and eco-friendly potting medium, (d) incorporation of <i style="">Azotobacter, Aspergillus</i> and VAMs during media preparation helps in better establishment and growth of plants, (e) sprays of organic extract have insignificant effect on the vitality of plantlets and (f) 1000 cm²provided optimal spacing for 3.8 plants. Financial implications of these findings are enormous.