INTRODUCTION Kodo millet (Paspalum scrobiculatum L.) is one of the important nutri cereal crop, which is mainly cultivated in India. Millets are mainly cultivated in low fertile soils of India for the purpose of food and fodder. The kodo millet is also known as ditch millet, rice grass, cowgrass, varagu, and Kodra. It is highly drought tolerant crop and suitable for low rainfall regions (Dubey, 1991). Millets are mainly used as an alternative to cereals because they have a good nutritional profile and we can cultivate with low input levels (Shahidi & Chandrasekara, 2013). In our country, the minor millets are cultivated over 4.58 lakh hectares and the production of small millets was 3.70 lakh tonners with the average productivity of 809kg ha-1. The important small millet cultivating states are Madhya Pradesh, Chhattisgarh, Uttarakhand, Karnataka, Maharashtra and Tamilnadu. The millet cultivation was gradually decreased due to green revolution; lower the productivity and less preference among the farming community. The consumption pattern of food is continuously changing due to the high cultivation and production of cereals and pulses over the millets. In recent days, the consumer preference is changing towards the millets because of diabetic prevalence in world. The continuous intake of kodo millet prevents from cardiovascular diseases and reducing the blood pressure and high cholesterol (Bunkar et al., 2021). The productivity of millets was very low due to improper nutrient management, cultivation under dry land conditions and less number of improved varieties. So the foliar fertilization of micro nutrients and adequate supply of macro nutrients are the important nutrient management practices followed to encourage the productivity in millets. The potassium application was not recommended for most of the minor millets in India. But the application of enough quantity of potassium recorded positive results in yield and productivity of millets (Sundaresh & Basavaraja 2017). In this regard, the experiment was conducted with different nutrient sources to check the yield and economics of kodo millet under irrigated condition. MATERIALS AND METHODS The field experiment was conducted at Eastern block, Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore during summer2021-22. The experimental farm was located in western agro climatic zone of Tamil Nadu at 11°08N latitude, 76°97E longitude with an altitude of 426 m above MSL. The experiment was laid out in a Randomized Block Design with three replication and eight treatments. The treatment consists of: T1 : RDF + MN Mixture @ 12.5 kg ha-1, T2 : RDF + Foliar spray of ZnSO4 @ 0.5% and FeSO4 @ 1% at AT & FI, T3 : RDF + 22 kg K ha-1 + MN Mixture @ 12.5 kg ha-1, T4 : RDF + 22 kg K ha-1 + Foliar spray of ZnSO4 @ 0.5% and FeSO4 @ 1% at AT & FI, T5 : RDF + 33 kg K ha-1 + MN Mixture @ 12.5 kg ha-1, T6 : RDF + 33 kg K ha-1 + Foliar spray of ZnSO4 @ 0.5% and FeSO4 @ 1% at AT & FI, T7 : RDF (44:22:0 kg NPK ha-1), T8 : Absolute Control. The sowing was taken at the first week of January and it was harvested at third week of May. The sources for N, P and K are urea, single super phosphate (SSP) and muriate of potash (MOP). In fertilizer application 50% of N, 100% P and K were applied as a basal dose with micro nutrient mixture (MN mixture). The micro nutrient mixture for small millets was purchased from Central Control Laboratory, Kudumiyanmalai. The foliar application of FeSO4 @1%, ZnSO4 @0.5% was given at active tillering and flower initiation stage. The observations on yield attributes, grain yield, straw yield and harvest index were recorded and analysed through ANOVA for Randomized Block Design (RBD) as per the procedure given by Gomez and Gomez (1984). The significant difference values were computed for 5% probability of error. When the variance ratio (F value) was found significant, critical difference (CD) values were computed for the comparison. RESULTS AND DISCUSSION Yield attributes. Data illustrated in Table 1 reveal that the yield contributing characters viz., number of productive tillers, number of grains per panicle, earhead length (cm), and test weight (g) were significantly influenced by the different nutrient management practices. The highest number of productive tillers (13.7), number of grains per panicle (209) and earhead length (14.5) were recorded by the application of RDF + 33 kg K ha-1 + Foliar spray of ZnSO4 @ 0.5% and FeSO4 @ 1% at active tillering and flower initiation stages of kodo millet which is due to enhanced nutrition of crop. The application of zinc and iron plays major role in vigorous growth due to cellular growth, differentiation and metabolic changes in plants and it was attributed with high yield attributes and grain yield in pearl millet (Ram et al., 2021). Sundaresh and Basavaraja (2017) reported similar results with the application of 125% K recorded higher productive tillers (4.47) in finger millet. The other yield attributes like earhead length (14.5 cm), number of grains per panicle (209) and 1000 grains weight (4.58 g) were recorded similar trend with RDF + 33 kg K ha-1 + Foliar spray of ZnSO4 @ 0.5% and FeSO4 @ 1% at AT & FI. Similar results were observed by(Patel et al., 2019) for pearl millet where maximum number of productive tillers and earhead length were recorded with foliar application of water soluble fertilizer (19:19:19) and ZnSO4 @ 0.5%. Similarly Sundaresh and Basavaraja (2017)reported application of potassium enhanced the root growth, translocation of photosynthates and increased photosynthetic activity in finger millet. Yield of kodo millet. The grain and straw yields of kodo millet as influenced by different nutrient management techniques are presented in Table 2. The maximum grain yield (2028 kg ha-1), straw yield (6822 kg ha-1) and harvest index (0.30) were recorded with the application of RDF + 33 kg K ha-1 + Foliar spray of ZnSO4 @ 0.5% and FeSO4 @ 1% at active tillering and flower initiation stage. T6 has recorded significantly higher yields over all other treatments and the lowest yield was recorded in absolute control (1379 kg ha-1) and it was on par with RDF + 33 kg K ha-1 + MN Mixture @ 12.5 kg ha-1. The increased grain and straw yields with RDF + 33 kg K ha-1 + Foliar spray of ZnSO4 @ 0.5% and FeSO4 @ 1% at AT & FI stage was mainly due to the enhanced fertilization which improves vegetative growth and yield attributing characters in kodo millet. The results confirm the findings of Srinivasa et al. (2019) has recorded higher grain yield (2266 kg ha-1) and straw yield (3814 kg ha-1) with the application of recommended dose of N, P2O5 + 40 kg K2O. Fulpagare et al. (2018) recorded similar results of higher grain yield (40 q ha-1) and stover yield (72.6 q ha-1) in pearl millet with RDF (60:30:25 NPK kg ha-1 + FYM @ 5t ha-1) + Foliar application of 0.1% chelated iron + 0.1 % chelated zinc. The application of potassium improved meristematic activity like cell enlargement elongation and it involves in root development, translocation of photosynthates and grain filling process (Charate et al., 2018). Application of zinc as a foliar spray was involved in IAA synthesis and metabolic process of plants (Ram et al., 2021) and iron promoting the early vigour and growth through enhancing the uptake of nutrients resulting in higher photosynthesis rate, metabolic and physiological process in plants (Babar et al., 2021). Economics. Highest gross (Rs. 89313) and net returns (Rs. 52559) and B:C ratio (2.43) were recorded with application of RDF + 33 kg K ha-1 + Foliar spray of ZnSO4 @ 0.5% and FeSO4 @ 1% at active tillering and flower initiation stage. The maximum cost of cultivation (Rs. 37174/ha) was recorded in T5 (RDF + 33 kg K ha-1 + MN Mixture @ 12.5 kg ha-1). This was mainly due to sufficient application of potassium and foliar nutrition of FeSO4 and ZnSO4 at active tillering and flowering initiation. The basal application of potassium produced higher grain and straw yield over other treatments.