Impacts of Reduced Nitrogen Application During Late Growing Season on Potato Tuber Quality and Profitability

View the project final report

Commodities

• Agronomic: potatoes

Practices

• Crop Production: application rate management, fertigation
• Education and Training: extension
• Energy: energy conservation/efficiency
• Farm Business Management: budgets/cost and returns
• Production Systems: general crop production

Harvesting and storage of immature potato tubers frequently results in significant economic losses in fresh market operations due to physical damage during harvest, weight loss and susceptibility to bruising in storage. A primary cause of immaturity is excessive nitrogen fertilization. Increased nitrogen can produce higher potato yields, however harvest damage and storage losses may offset any economic returns from increased yield. The proposed research will focus on understanding the effects of different rates of late-season application of nitrogen on tuber maturity of four russet potato cultivars. Nitrogen rates for each cultivar will be evaluated based on tuber yield, tuber skin durability (skin set), tuber moisture loss and pressure bruise susceptibility. The project goal is to determine if potatoes grown in a sustainable system of reduced nitrogen inputs can produce improved economic returns.

Due to our short season, and in anticipation of the success of this proposal, we are proposing to start field research in summer 2010.

1. May-August 2010: Conduct literature review and research planning. Plant field trials of four different cultivars at SLVRC and apply treatment rates of nitrogen. Prepare spreadsheets and organize for experimental harvest.

2. September-November 2010: Evaluate tuber maturity and yield and harvest damage. Prepare samples for storage experiments to determine shrink and pressure bruising. Conduct initial analysis of yield data, harvest damage data and moisture loss data, as well as cost and benefit analysis.

3. February-April 2011: Evaluate shrink and pressure bruise from storage experiments. Analyze results and present results at grower meetings. Evaluate methodology and results to determine potential improvements for second year research. Prepare seed and land for second year field trials.

4. May-August 2011: Plant second year field trials for four varieties at SLVRC and apply treatment rates of nitrogen. Prepare spreadsheets and organize for experiment harvest.

5. September-November 2011: Evaluate yield and harvest damage and establish second year storage experiments for determining shrink and pressure bruising. Conduct initial analysis of yield data, harvest damage data and moisture loss data.

6. February-May 2011: Evaluate shrink and pressure bruise from storage experiments. Analyze results and present results at grower meetings. Compare results across both years' experiment data. Prepare submissions for peer-reviewed journals and commercial publications. Send surveys to growers on changes made to fertilizer regime and adoptions of research results. Prepare final SARE report.