DRAFT SOW Hop Seedling Project.pdf

United States Department of Agriculture (USDA) Agricultural Research Service (ARS) Pacific West Area (PWA) Forage Seed and Cereal Research Unit

3450 SW CAMPUS WAY

Corvallis, OR 97331

Statement of Work: Hop “Early‐Line” Evaluation Germplasm.

This project will involve planting, germination, screening and selection of resistant hop germplasm offspring from seed to whole plants. Specific temperature requirements for disease screening, periodic trimming of plants under consultation with USDA staff, daily watering and regular fertilizer applications will be required.

Specific steps are as follows:

1. Hop seeds will be planted by the contractor into ~100‐cell flats. Approximately 40‐60 K seeds per year will be provided by USDA staff. Goal for completion: November 20th

2. Contractor keeps the flats and flats will be kept moist and stored under cold conditions (~ 5 deg C) for 8 weeks

3. Contractor moves flats into a hot house for germination. Typical germination rates range from 50‐80 % of total seeds planted. Goal for completion: January 15th

4. USDA staff will enter the contractor facility and will inoculate plants with powdery mildew disease. The powdery mildew disease is an obligate pathogen and its primary host plant is hops and is not a disease threat to any other plant species. USDA staff will mark or designate plants for retention. Plants not marked for retention are discarded by the contractor. Typical culling rates vary among crosses but can range from 40 ‐ 50% of all germinated seedlings are culled. Remaining seedlings 20 – 40 K. Goal for completion: February 15th

5. Contractor will transplant retained plants into 2” pots with labels for each flat. Goal for completion: March 1st

6. Transplanted seedlings will be moved into a warm glasshouse. USDA staff will enter the contractor facility and will inoculate the plants with powdery mildew a second time.

Goal for completion: March 10th.

7. USDA staff will enter the contractor facility and mark or designate plants for retention.

Plants not marked for retention are discarded by the contractor. Goal for completion:

March 30th. Remaining seedlings will range from 15 – 30 K.

8. Retained plants will be potted up into 4” pots and placed in a warm, humid greenhouse with overhead irrigation/misting for inoculation with downy mildew spores. Goal for completion is April 15th.

9. USDA staff will enter the contractor facility and will inoculate plants with downy mildew disease. The downy mildew disease is an obligate pathogen with primary host as hops.

It is generally not a disease threat to any other plant species. USDA staff will mark or designate plants for retention. Plants not marked for retention are discarded by the contractor.

10. USDA staff will mark or designate plants for retention. Plants not marked for retention are discarded by the contractor. The goal of completion being May 15th. Contractor will re‐pot retained seedlings into 1‐gal pots. Remaining seedlings will range from 5 – 10 K.

11. Selected offspring will be returned to USDA‐ARS for further handling.