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2022 Midwest Vegetable Guide

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Root Crops – Horticulture 256 Midwest Veg Guide 2022 Celeriac This type of celery (Apium graveolens var. rapaceum) has been bred as a root crop with low-growing bushy foliage and a large, bearded, globe-shaped hypocotyl/root structure with a celery flavor. Start as transplants 8 to 10 weeks before planting, and plant in early spring before last frost date. Transplant in rows 24 to 30 inches apart with plants 6 to 8 inches apart in row. For an acre of transplanted celeriac, you will need 2 to 4 ounces of seed to start in the greenhouse. The full flavor is only reached after first frost. Time from transplanting to harvest ranges from 80 to 90 days. From seeding in cell trays, add 20 days. Horseradish This perennial Brassica (Armoracia rusticana) is grown commercially in Illinois and Wisconsin as an annual crop from root cuttings. The roots are not eaten raw, but grated as a spice for condiments and flavoring. Type I varieties produce large smooth roots and are highly resistant to turnip mosaic virus and white rust. Type III varieties produce large roots but are highly susceptible to those two diseases. Type II varieties produce large roots with bark-like exterior, with intermediate resistance to those two diseases. Numbered commercial varieties are maintained by a small breeding effort supported directly by the largest growers of the commodity. Plant root sets in early spring before last frost date. Sets should be 1/2 to 3/4 inches in diameter and 10 to 16 inches long. Root set ends that were closest to the plant (thicker end) and the ends that were farthest from the plant (thinner end) have to be planted thick end to thin end along the row, with the thick ends elevated about 2 inches higher than the thin end. This is accomplished by first scooping divots in rows 36 inches apart and 12 to 24 inches apart in-row. Then lay roots by hand into the divots with the thin end in the deepest part. That is roughly 10,000 sets per acre. Cover the roots with a disc-hiller to a depth of 5 to 8 inches. Horseradish plants put the most size on their roots in the late summer and fall. Mechanical harvests with an undercutting chain conveyor take place in November until freeze-up and continues as soon as soils can be worked in the spring. Time from transplanting to harvest ranges from 200 to 250 days. Radish, Rutabaga, and Turnip The roots of these Brassica plants are strong to mildly- flavored and come in diverse size, colors, and shapes. For all of these crops, the flavor is sweeter or milder when roots reach marketable size in cool conditions. Radishes (Raphanus sativus) come in globe-shaped bright red varieties that are the most common in United States markets, but market opportunities exist for the torpedo-shaped varieties, as well as for white, black, yellow, green, pink and deep red varieties. Most have white internal flesh, but some have pink internal flesh. Radishes become pungent during hot weather. They can be direct-seeded in single rows 16 to 30 inches apart, or in three-row beds with 10 to 12 inches between rows and 36 inches between beds, center to center. Plant 12 to 15 per foot of row. Seed 10 to 15 pounds per acre. Rutabagas (Brassica napus supsp. rapifera) are the largest and mildest-flavored of these root crops. They are commonly white or yellow skinned with white internal flesh. Some develop a pink, purple, or green blush on the shoulders of the root when exposed to the sun. They can be direct-seeded in single rows 24 to 30 inches apart. Plant 3 to 4 seeds per foot of row. Seed 1 to 2 pounds per acre. Turnip roots (Brassica rapa subsp. rapa) are larger than a radish, but smaller than a rutabaga, with a flavor that is an intermediate intensity between radish and rutabaga. The variety options are similar in appearance to rutabaga. They can be direct-seeded in single rows 14 to 18 inches apart. Plant 2 to 3 inches apart in row. Seed 1 to 2 pounds per acre. Both mechanical and hand harvest is common and starts when roots are of suitable size for the market. Time from seeding to harvest ranges from 30 to 60 days for radishes and turnips, or 80 to 100 days for rutabagas. Fertilizing pH: Maintain a soil pH of 6.0 to 6.8. For beets, maintain a soil pH of 6.5 to 7.0. Before planting, apply 60 pounds N per acre, 0 to 160 pounds P 2 O 5 per acre, and 0 to 200 pounds K 2 O per acre based on soil test results and recommendations from your state. For beets grown on sandy soils, light-colored silt and clay loams, and alkaline, dark-colored soils apply boron at 2.5 to 5 pounds per acre applied over the row at planting. Do not let boron contact seed. Beans, peas and cucurbits are sensitive to boron so use caution if these crops will follow beets, especially in the same season. For carrots grown on muck soil with a pH greater than 6.0, apply 6 pounds of manganese sulfate per acre applied over the row at planting, or in a starter band. For horseradish, add 1 to 2-1/2 pounds per acre boron and 15 to 25 pounds per acre sulfur with the initial N–P–K broadcast application. An optional sidedress application of 50 to 75 lb/acre N can be made 8 to 12 weeks after planting, but overapplication of nitrogen reduces root quality. For most other root crops, sidedress with 30 to 60 pounds N per acre 4 to 6 weeks after planting. Most radishes mature quickly and do not require sidedressing. Reduce the amount of fertilizer N applied by the value of N credits from green manures, legume crops grown in the previous year, compost and animal manures, and soils with more than 3 percent

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