Abstract: Over the past few decades there has been considerable research evaluating sensor-based technologies for in-season application of Nitrogen (N). The majority of this research has been done on wheat (Triticum aestivum L.) and corn (Zea mays L.), with little research on other crops. A field study was established in Brookings, SD to evaluate the GreenSeeker Hand Held optical sensor (NTech Industries, Ukiah, CA) for measuring in-season N status on canola (Brassica napus L). Sensor readings and plant biomass samples were collected at four different intervals through the rosette to early bud growth stages. The sensor measures reflectance in the red and Near Infrared (NIR) regions of the electromagnetic spectrum and calculates a Normalized Difference Vegetation Index (NDVI). The ability of the sensor readings to measure biomass, plant N uptake and predict seed yield and protein for each sampling date was determined. In general, in-season plant biomass, plant N concentration and seed yield increased with increasing N rate. Sensor readings (NDVI) showed a significant relationship with plant biomass, N uptake and seed yield regardless of sampling dates. Measurements collected in mid May resulted in the highest correlation with plant biomass, while the relationship increase with later sampling dates for yield. Results suggest that existing sensor-based variable nitrogen technology developed has the potential to be utilized for other non-traditional crops such as canola.