Dwivedi, D. K.Kumar, Pankaj2018-02-062018-02-062017http://krishikosh.egranth.ac.in/handle/1/5810040472An experiment was conducted in the year 2016-17 on potato with potato variety (Kufri Ashoka) with seven treatments viz., T1: 50% RDF of NPK, T2: 100% RDF of NPK, T3: 150% RDF of NPK, T4: 100% RDF of PK, T5: 100% RDF of NK, T6: 100% RDF of NP and T7 All the growth parameters like per cent plant emergence, plant height, shoots per plant, leaves per plant, dry matter accumulation and bulking rate were significantly influenced by the different rate of NPK application. Among all treatments, T: Absolute control (without NPK) were laid out in aRandomized Block Design with four replications. Five competitive plants were selected randomly from each treatment to record data on various growth and yield parameters at Tirhut College of Agriculture Farm, Dholi (Muzaffarpur), Bihar during rabi season. The soil of the experimental plot was Entisol, sandy loam in texture and low in available NPK with a pH of 8.30. It has semi-arid, sub-tropical climate, which is greatly influenced by South-West monsoon with an average annual rainfall of 1270 mm 3proved significantly superior in all growth parameters, yield attributing characters, N, P and K content, uptake in plant, available N, P2O5 and K2O in soil, economics, fertilizer use efficiency except agronomic efficiency and production use efficiency during the experimentation. Escaping of any major nutrient result in a poor all growth parameters and yield attributing characters. The treatment T3 –150% RDF of NPK was found significantly superior over all the treatments. TreatmentT3 –150% RDF of NPK recorded significantly higher number of tubers per plant, weight of tubers per plant and grade wise yield of tubers in the categories of 25-50 g, 50-75 g and > 75 g. The T3 –150% RDF of NPK registered significantly higher fresh tuber yield over other treatment. Thus the increment in potato tuber yield was noticed by increasing levels of nitrogen, phosphorus and potassium. Also the marketable yield, vine yield, tuber: vine ratio and harvest index was recorded highest in treatmentT3 –150% RDF of NPK. Chemical studies like N,P and K –content and uptake by tuber and vine as well as total uptake was maximum under treatment,T3 –150% RDF of NPK. Likewise, fertilizer use efficiency for N, P and K was significantly higher under treatment with highest nitrogen, phosphorus and potassium application. Agronomic use efficiency for nitrogen, phosphorus and potassium was found significantly superior in treatment, T2 –100% RDF of NPK. Productionuse efficiency for nitrogen, phosphorus and potassium was found significantly superior in treatment, T4: 100% RDF of PK,T5: 100% RDF of NK and T6: 100% RDF of NP. The fresh tuber yield was recorded significantly higher by the treatmentT3 –150% RDF of NPK (263.53q/ha). The gross return (₹210824/ha),net return (₹130085/ha) and B: C ratio (1.61) was recorded significantly higher by the treatmentT3 –150% RDF of NPK. An increase in nitrogen, phosphorus and potassium levels also enriched the post-harvest nitrogen, phosphorus and potassium level of the experimental field.ennullThesis