Experiment was conducted at the National Horticultural Research Institute (NIHORT), Ibadan between March and June, 2014 on the influence of different soil amendments on insect population and yield of carrot. NIG-44, NIG-45 and Starke Ayres varieties were Sown on raised plot size 3m x 3m and spaced 30cm x 30cm. The design was a Randomized Complete Block Design (RCBD) consisting of four treatments and replicated three times. The treatments were Poultry manure, Cow dung, NPK 15:15:15 fertilizer and Control (no nutrient application). Poultry manure and Cow dung each at 20 ton ha-I were applied on the respective treatment plots one week before sowing while 60 kg ha-I of NPK 15:15:15 fertilizer was applied per plant in ring form six weeks after sowing.The major insect observed on the leaves during the production period was a dark coloured shiny beetle Systena blanda whose occurrence was significantly high at the early vegetative stage of the plant growth but the population gradually reduced as the plant matured. Population of the beetle was significantly higher on Variety NIG-44 which was not significantly different from NIG-45. However, lower population of the insect was observed in Starke Ayres variety. NIG-44 and NIG-45 with the application of NPK 15:15:15 produced significantly higher number of leaves and higher plant height followed by cowdung and then poultry manure while all the varieties planted without any amendments produced significantly lower number of leaves and plant height. However, in the three varieties planted, plots applied with poultry manure produced significantly higher fruit weight and fruit diameter while variety NIG-45 and Starke Ayres with NPK 15: 1 5: 15 produced significantly higher fruit length.