Full Length Research Article GROWTH AND YIELD OF SPINACH (SPINACIA OLERACEA L.) UNDER FLUCTUATING LEVELS OF ORGANIC AND INORGANIC FERTILIZERS 1* Muhammad Iqbal Jakhro, 2 Syed Ishtiaq Shah, 1 Amanullah, 1 Muhammad Yaqub Zehri, 1 Zulfiqar Ali Rahujo, 1 Saeed Ahmed, 1 Sher Ahmed and 2 Muhammad Aftab Jakhro 1 Balochistan Agricultural Research & Development Centre Quetta, Pakistan 2 Sindh Agriculture University Tandojam Pakistan ARTICLE INFO ABSTRACT A field trial was conducted in a three replicated Randomized Complete Block Design during 2016 at Sindh Agriculture University to examine the production of spinach under varying levels of organic and inorganic fertilizers. The treatments included: T 1 =Control, T 2 =50 kg N ha -1 , T 3 =50 kg N + 4 tons FYM ha -1 , T 4 =50 kg N + 6 tons FYM ha -1 , T 5 =75 kg N ha -1 , T 6 =75 kg N + 4 tons FYM ha -1 and T 7 =75 kg N + 6 tons FYM ha -1 (FYM = Farm yard menure). The results revealed that spinach plantation nourished with 75 kg N + 6 t ha -1 FYM produced the plants of 37.42 cm height on average, produced 18.05 leaves plant -1 , 43.31 g fresh weight, took 23.33 days to first cutting, 23.47 cm leaf length, 4.29 kg spinach yield plot -1 and 7.152 t ha -1 spinach yield. The crop fertilized with 75 kg N + 4 t ha -1 FYM produced plants of 33.05 cm height, 16.26 leaves plant -1 , 39.02 g fresh weight, took 24.00 days to first cutting, 21.97 cm leaf length, 3.53 kg spinach yield plot -1 and 5.879 t ha -1 spinach yield. The crop given 75 kg N ha -1 only (no FYM) produced plants of 30.76 cm height, 14.73 leaves plant -1 , 35.34 g fresh weight, took 24.67 days to first cutting, 18.55 cm leaf length, 2.97 kg spinach yield plot -1 and 4.955 t ha -1 spinach yield. The values for almost all the characters declined with decreasing N and FYM levels and spinach crop given 50 kg N ha -1 + 6 t ha -1 FYM, produced plants of 29.97 cm height, 14.70 leaves plant -1 , 35.28 g fresh weight, took 26.00 days to first cutting, 18.50 cm leaf length, 2.73 kg spinach yield plot -1 and 4.545 t ha -1 spinach yield. The treatment 50 kg N ha -1 + 4 t ha-1 FYM, 50 kg ha -1 N (without FYM) as well as control resulted in decline in value for all the traits investigated, minimum being in control. It was concluded that the spinach growth and yield as substantially higher under combined application of organic manures (FYM) in addition to inorganic nitrogen (as urea); and 75 kg N + 6 t ha -1 FYM resulted in optimum crop performance; while decrease in N, FYM or N application without FYM showed adverse impact on spinach yields. Copyright©2017, Muhammad Iqbal Jakhro et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. INTRODUCTION Spinach is leafy vegetable, botanically named as Spinacia oleracea. It is an edible flowering plant belongs to the Amaranthaceae family and probably originated in the central and southwestern Asia. The plant may survive over winter in temperate regions. The leaves are alternate, simple, and ovate to triangular-based, very variable in size from about 2–30 cm long and 1–15 cm broad, with larger leaves at the base of the plant and small leaves higher on the flowering stem. The flowers are inconspicuous, yellow-green, 3–4 mm diameter, maturing into a small, hard, dry, lumpy fruit cluster 5–10 mm across containing several seeds. *Corresponding author: Muhammad Iqbal Jakhro, Balochistan Agricultural Research & Development Centre Quetta, Pakistan. Common spinach, Spinacia oleracea, was long considered to be in the Chenopodiaceae family, but in 2003, the Chenopodiaceae family was combined with the Amaranthaceae family under the family name 'Amaranthaceae' in the order Caryophyllales. Within the Amaranthaceae family, Amaranthoideae and Chenopodioideae are now subfamilies, for the amaranths and the chenopods, respectively (Rolland and Sherman, 2006).In the nutritional context, the 100 g edible spinach contains Energy 97 kJ (23 kcal), Carbohydrates 3.6 g, Sugars 0.4 g, Dietary fiber 2.2 g, Fat 0.4 g, Protein 2.9 g, Water 91.4 g, Vitamin A equiv. 469 μg (59%), Vitamin A 9377 IU, Beta- Carotene 5626 μg (52%), Lutein and zeaxanthin 12198 μg, Thiamine (vit. B1), 0.078 mg (7%), Riboflavin (vit. B2), 0.189 mg (16%), Niacin (vit. B3), 0.724 mg (5%), Vitamin B6 0.195 mg (15%), Folate (vit. B9) 194 μg (49%), Vitamin C 28 mg ISSN: 2230-9926 International Journal of Development Research Vol. 07, Issue, 02, pp.11454-11460, February, 2017 International Journal of DEVELOPMENT RESEARCH Article History: Received 27 th November, 2016 Received in revised form 17 th December, 2016 Accepted 28 th January, 2017 Published online 28 th February, 2017 Available online at http://www.journalijdr.com Key Words: Spinach, Nitrogen, FYM, Yield.