Determining the Optimal Nitrogen Rate for New Chipping Potato Varieties in the Columbia Basin

In the Columbia Basin, chipping potato varieties are gradually being adopted for processing into French fries and chips. However, limited information is available on their field performance and nitrogen requirements, highlighting the urgent need for a nutrient management guideline. A field trial was conducted at the Hermiston Agricultural Research and Extension Center field facility to evaluate the nitrogen requirements of two potato varieties, Waneta and NYGR14Q9-5, under different N application rates (0, 112, 224, 336, and 448 kg ha⁻¹). Results indicated that NYGR14Q9-5 showed a better field performance than Waneta, with an average total yield 26% greater. The specific gravity of NYGR14Q9-5 was 1.081, compared to 1.070 for Waneta. The tubers larger than 170 g accounted for 54% of the total yield of Waneta, while they made up 71% of the total yield of NYGR14Q9-5. Nitrogen application significantly affected both total and marketable yields. The highest yield was observed at an N rate of 112 kg ha⁻¹ for Waneta, while at 336 kg ha⁻¹ for NYGR14Q9-5. Continuous studies are needed to evaluate field performance and determine the optimal N rates for these varieties, supporting growers in successfully producing chipping potatoes in the region.