Model (Smooth White). For trial: Hollow Crown, Andover (resistant to both brown canker, Itersonilia perplexans, and Phoma canker), Gladiator (resistant to Itersonilia canker).

SOIL

Deep, loose fertile soils that have good water-holding capacity and a pH of 6.0 or above are necessary for the development of long, straight roots. Well-drained sandy loams, peat, and mucks are ideal for parsnip production.

SEEDING AND SPACING

Parsnip seed numbers approximately 12,000 per ounce. Sow seed as early in the spring as possible at a rate of 3 to 5 lb/acre to a depth of 1/4 to 3/4 inches. Space plants within the row 2 - 4 inches apart and space rows at least l8 inches apart.

FERTILIZER

A soil test is the most accurate guide to fertilizer requirements. The following are general guidelines. Broadcast and disc, or band, at time of planting the following:

Nitrogen: 30-50 (N) 30-50 lb/acre.
Phosphate: 145-155 (P2O5) lb/acre.
Potash: 110-130 (K2O) lb/acre as sulfate of potash

Sidedress with 25-35 lb N/acre about 6 weeks after seeding.

HARVESTING, HANDLING, AND STORAGE

Parsnips yield approxtimately 160-200 cwt/acre. Parsnips may be dug, topped, and stored in cold storage, in a cellar, or in an outdoor pit. They become sweeter and better flavored after a short period of cold storage. They may also be left in the ground over winter or until needed. Although parsnips can be harvested several ways, single or multiple-row harvesters can be custom built by Krier Engineering, 4774 Morrow Rd., Modesto, CA. Contact Mr. Alex Krier, 800-344-3218, for more information.

STORAGE (Quoted or modified from USDA Ag. Handbook 66 and other sources)

Store parsnips at 32 F and 98 to 100 % relative humidity. Parsnips have nearly the same storage requirements as topped carrots and should keep for 4 to 6 months at 32 F. Only sound, healthy roots should be stored -- never bruised or damaged ones. The main storage problems with parsnips are decay, surface browning, and their tendency to shrivel. The surface browning or yellowing is due to enzymatic oxidation of phenolic compounds. Refrigeration will retard both the discoloration and decay.

Parsnips may be subjected to considerable amount of freezing without serious damage. For example, roots exposed at 20 F for 3 hours showed little damage other than slight softening and discoloration when thawed over 24 hours at 70 F. However, they should be protected from hard freezing and should be handled with great care while frozen. Parsnips held at 32 to 34 F for 2 weeks after harvest attain a sweetness and high quality equal to that of roots subjected to frosts for 2 months in the field. Parsnips dry out readily in storage; hence, it is essential that the humidity of the storage be kept high. They will remain crisper and firmer, with less weight loss and better color, if stored at a relative humidity of 98 to 100 % rather than 90 to 95 %. In Canadian research, a jacketed type storage provided optimum conditions for parsnip storage. Ventilated polyethylene crate liners aid in preventing moisture loss. Waxing is not particularly effective in preventing wilting and may hasten browning.

Storage diseases are gray mold, parsnip canker, bacterial soft rot, and watery soft rot.

PACKAGING

Parsnips are commonly packaged in 25-lb film bags, or 12-lb cartons, holding 12 cello bags, 1 lb each.

DISEASE CONTROL

The Pacific Northwest Disease Control Handbook has no control entries for this crop. Proper rotations, field selection, sanitation, spacings, fertilizer and irrigation practices can reduce the risk of many diseases. Fields can be tested for presence of harmful nematodes. Using seed from reputable sources reduces risk from "seedborne" diseases.