IOSR Journal of Agriculture and Veterinary Science (IOSR-JAVS) e-ISSN: 2319-2380, p-ISSN: 2319-2372. Volume 7, Issue 5 Ver. III (May. 2014), PP 31-42 www.iosrjournals.org www.iosrjournals.org 31 | Page Effect of NPK Spray Formulation on Growth of Two Cultivars of Orchid (Mokara Sp.) Md. Hossen Ali 1 , Prosanta Kumar Dash 2* , Md. Monirul Islam 3 , Mahtalat Ahmed 4 and Trishita Mondal 5 1 (Student, Agrotechnology Discipline, Khulna University, Khulna-9208, Bangladesh) 2 (Assistant Professor, Agrotechnology Discipline, Khulna University, Khulna-9208, Bangladesh) 3 (Professor, Agrotechnology Discipline, Khulna University, Khulna-9208, Bangladesh) 4 (Professor, Agrotechnology Discipline, Khulna University, Khulna-9208, Bangladesh) 5 (Student, Agrotechnology Discipline, Khulna University, Khulna-9208, Bangladesh) Abstract: A pot experiment was conducted at Plant Breeding and Biotechnology Laboratory of Agrotechnology Discipline, Khulna University, during the period from October 2012 to May 2013 to study the effect of NPK spray formulation on growth of two cultivars of Orchid (Mokara sp.). Four spray formulations: control (Tap water), spray formulation 1 (N:P:K = 90:45:45 or 2:1:1), spray formulation 2 (N:P:K = 135:90:45 or 3:2:1), spray formulation 3 (N:P:K = 180:135:90 or 4:3:2) and two cultivars (Mokara Diehard Red and Mokara Yellow Anne) were used as treatment variables. Layout system was Completely Randomized Design (CRD) under factorial arrangement with three replications. Spray formulation had significant influence on growth of the two cultivars tested. Significantly highest plant height was obtained (39.83 cm) at 290 DAP from Mokara Diehard Red Variety with spray formulation 3 compared to other spray formulations. Highest leaf area index (0.16) was obtained from Mokara Diehard Red Variety with spray formulation 3 at 290 DAP mainly due to increased number of leaf and total leaf area. Mokara Diehard Red cultivar with spray formulation 2 enhanced plant growths and resulted greater leaf number (21.33) and leaf length (26.83 cm) to other cultivars cultivated. Plant height as well as other growth parameters was gradually increased due to suitable treatment combination. Results of the study revealed that spray formulation 3 would be suitable for Mokara Diehard Red cultivars cultivation under pot condition. Keywords: Spray, Formulation Cultivars, Growth and Treatment I. Introduction Orchids are one of the momentous groups of flowering plants belong to the largest and most multiform family Orchidaceae. This family consists of about 700-800 genera and more than 25,000 species in the world (Singh and Roy, 2004). Among the flowering plants, orchids are excellent items for garden and can be grown in beds, pots, baskets etc. They are known for their loudly blooms and are found in diverse habitats. Orchids are the most fascinating variety and beautiful of all flowers due to its long life, attractive structures and excellent color (Sing and Voleti, 1995). Orchids have occupied top position among the flowering plants valued for cut flowers as well as pot plants. They exhibit an incredible range of diversity is in shape and size of their flowers. Orchid industry plays an important role as a source of foreign exchange. World-trade in floriculture today has turned over at about $ 76, 62,924 involving more than 150 countries (Manilal and Sathish, 2008). Orchids vary in their growth habits. Orchids are divided into two types namely sympodial and monopodial on the basis of their growth habit (Royer, 2003). Mokara orchids are monopodial type. The monopodial orchids have indeterminate terminal growth. This type of orchid have aerial root and have no pseudo bulb (Hawkeye, 2005). Mokara orchids are inter-genic hybrids of arachnis × ascocentrum × vanda which have the largest number of colors compared to other orchids. It has an amazing diversity of plant habit flower form and color. It’s commonly named by the smile orchid. Due to their delicacy and bright colors with its striking form of a starfish, Mokara are popular in wedding bouquets (Ghoshal and Das, 2008). Both the plants and the blooms vary greatly in shape and size, while the colors at the blooms range from white through flushes to yellow rose and to the deepest possible crimson purple. Orchids grow over wide ranges of climatic conditions. Majority of the cultivated orchids were native of tropical countries and found humid tropical forests of south and Central America (Chakrabarti, 1999). They are also distributed through Mexico, India, Myanmar, China, Thailand, Malaysia, Philippines and Australia (Rao, 2000). Orchids having flowers of charming beauty and good keeping qualities, they are the most wonderful items for indoor decorations (Patil, 2001). As cut flower and pot plants orchids are high demandable items. They are also in different purposes as fragrant, glue, medicine, drinks and flavoring. Orchids are marketed globally and the orchid industry has contributed substantially to the economy of many Asian countries (Laws, 1995). Thailand is now most important centre for