Tomato (Lycopersicon esculentum Mill) production in Ethiopia is constrained by a number of factors among which the application of sub-optimal fertilizer and high yielder variety selection are the most important in Guder area. Therefore, this experiment was conducted at Ambo University Guder campus, Ethiopia to study the influence of NPS fertilizer on yield and yield components of tomato varieties. The experiment was laid out in a randomized complete block design with factorial arrangement in three replications, with five levels of NPS fertilizer 0, 50, 100, 150, 200kg ha-1 and three tomato varieties namely Fetan, Cochoro and ARP tomato d2. Data were collected on phenology, yield and yield components of the crop. The results showed that number of fruit clusters per plant, number of fruits per plant, days to 50% fruiting and total marketable yield was highly influenced by the interaction effect of varieties and NPS fertilizer. However, fruit number per cluster and plant height, was significantly influenced by the main effect of variety. Application of 150kg and 200kg NPS ha-1 has significantly increased number of fruits per plant and fruit yield per plant in all tomato varieties than other treatment. However, the highest marketable fruit yield of 26.57 t ha-1 was obtained from the application of 150kg NPS ha -1 with Fetan variety. The maximum net benefit of about Birr 252091ha-1 with marginal rate of return 3122% was gained from the application of 150kg NPS ha-1. Hence, the use of 150kg NPS ha-1 fertilizer can be promoted for the improvement of tomato production in the study area.

Keywords: NPS fertilizer, Tomato varieties, growth parameters, fruit yield.