A field experiment was conducted during the Rabi season 2017–2018 (October–March) at the University of Agriculture, Peshawar research farm to examine the influence of different nitrogen (N) and phosphorus (P) levels on two different oat varieties: Australian and Ukrainian. The treatments included control and three levels of nitrogen and phosphorus at 30, 60, and 90 kg ha−1. The treatments were arranged in randomized complete block design (RCBD) and replicated three times. The findings showed that the oat varieties were significantly different from one another in yield and yield parameters. The Australian variety recorded higher emergence (49 plants m−2), days to emergence (15 days), days to flowering (122 days), days to maturity (145 days), plant height (142.7 cm), number of leaves (6.03 leaves plant−1), number of tillers (92.2 tillers m−1), biological yield (8,179.2 kg ha−1), and grain yield (3,725.6 kg ha−1) than the Ukrainian variety. Similarly, different N and P levels, the maximum days to emergence, days to flowering, and days to maturity were recorded in a control plot. The application of 105 kg N + 90 kg P ha−1 was statistically similar to the application of 105 kg N + 60 kg P ha−1. Maximum emergence (60 plants m−2), number of leaves (7.0 leaves plant−1), plant height (118.6 cm), number of tillers m−1 (102.6), biological yield (9,687.5 kg ha−1), and grain yield (4,416.7 kg ha−1) were determined in Australian variety. Based on the findings of this study, the Australian variety performed better in terms of yield and yield components and the application of N and P fertilizers at the rate of 105 kg N + 60 kg P ha−1 produced the best results in both oat varieties.
