Field experiments were conducted with four different dimensions of carrot roots (5, 10, 15 & 20) and four different P levels (0, 50, 75 and100 kg ha^-1) to evaluate the response of carrot growth, development, seed yield umble^‑1 under the semi-arid climatic condition. Total 16 treatments in various combinations were used in four replications.Results showed that large and thick root dimension of 20 cm effected days to flowering and produced early flowering as compared to other treatments. P fertilization also influenced carrot phenology and noted that early flowering produced by carrots with P fertilization up to 100 kgha^-1. Taller plantswere produced by 10 cm root size, which was statistically similar to 15 cm root dimension while dwarf seedling were recorded in 5 cm root dimension. Increasing phosphorous level showed ameliorating effect towards carrot growth and shoot improvement and noted highest carrot shoot with 100 kg P ha^-1.It was worthy noted that P fertilization was promising for improvement in umbel plant^-1and we observed with P application of 100 kg ha^-1. Similarly optimum root dimension of about 15 cm resulted in more number of umbel plant^-1 that was decreased with small size of root thickness. Highest seed yield umbel^-1 was recorded in plants treated with 100 kg P ha^-1.  Similarly root dimension of 20 cm produced more seed yield umbel^-1, whereas least seed yield umbel^-1 was recorded in roots of stickling size of 5 cm.

Key words: Carrot, (Daucuscarrota), phosphorous, seed production, roots dimension