Monday, January 12, 2015

Sunchokes , A sustainable crop that benefits humans and pollinators.

PrincipleNutrient ValuePercentage of RDA
Energy73 Kcal3.7%
Carbohydrates17.44 g13%
Protein2 g4%
Total Fat0.01 g<1%
Cholesterol0 mg0%
Dietary Fiber1.6 g4%
Folates13 µg3%
Niacin1.3 mg8%
Pantothenic acid0.397 mg8%
Pyridoxine0.077 mg6%
Riboflavin0.060 mg4.5%
Thiamin0.200 mg17%
Vitamin A20 IU<1%
Vitamin C4 mg7%
Vitamin E0.19 mg1%
Vitamin K0.1 µg<1%
Sodium4 mg<1%
Potassium429 mg9%
Calcium14 mg1.4%
Copper0.140 mg15%
Iron3.40 mg42.5%
Magnesium17 mg4%
Manganese0.060 mg2%
Selenium0.7 µg1%
Zinc0.12 mg1%
Carotene-β12 µg--
Carotene-α0 µg--
Lutein-zeaxanthin0 µg--

The Jerusalem artichoke (Helianthus tuberosus), also called sunroot,sunchokeearth apple ortopinambour, is a species of sunflower native to eastern North America, and found from eastern Canada and Maine west to North Dakota, and south to northern Florida and Texas It is also cultivated widely across the temperate zone for its tuber, which is used as a root vegetable growing to 1.5–3 m (4 ft 11 in–9 ft 10 in) tall with opposite leaves on the upper part of the stem but alternate below.The leaves have a rough, hairy texture and the larger leaves on the lower stem are broad ovoid-acute and can be up to 30 cm (12 in) long, and the higher leaves smaller and narrower.

The flowers are yellow and produced in capitate flower heads, which are 5–10 cm (2.0–3.9 in) in diameter, with 10–20 ray florets.

The tubers  are elongated and uneven, typically 7.5–10 cm (3.0–3.9 in) long and 3–5 cm (1.2–2.0 in) thick, and vaguely resembling ginger root  in appearance, with a crisp texture when raw. They vary in colour from pale brown to white, red, or purple.

The artichoke contains about 10% protein, no oil, and a surprising lack of starch. However, it is rich in the carbohydrate inulin  (76%), which is a polymer of the monosaccharide fructose. Tubers stored for any length of time will convert their inulin into its component fructose. Jerusalem artichokes have an underlying sweet taste because of the fructose, which is about one and a half times sweeter than sucrose.

Sunchokes have also been promoted as a healthy choice for type 2 diabetics, because fructose is better tolerated by people who are type 2 diabetic. It has also been reported as a folk remedy for diabetes.[Temperature variances have been shown to affect the amount of inulin the Jerusalem artichoke can produce. When not in tropical regions, it has been shown to make less inulin than when it is in a warmer region.

Strains vary by skin color, root shape, and maturation time. White-skinned strains include the early-maturing ‘Stampede’ variety, which develops crisp, round roots quickly enough to be grown in climates with short summers. The roots of slower-growing ‘Clearwater’ and ‘White Fuseau’ are longer, which makes them easier to scrub and peel.

Red-skinned strains include ‘Red Fuseau,’ which has red skin over topshaped roots with few attached round nodules, making the roots easy to clean. The roots of ‘Red Rover,’ ‘Waldspinel,’ and a few other red varieties are so long that these varieties are sometimes called “fingerling sunchokes.”

Sunchokes do very well under light insect feeding from Japanese beetles and the like. There is no need to worry about the insect damage to the plant, they take it like a champ, and therefore require no pest management. 
The plant will put sometimes over 100 flowers which are loved by bees and butterflies. These flowers usually come out after your regular sunflowers have already died off making it an excellent crop for extending feeding sources for pollinators . Stepping on some of the canes while they are growing or "lodging "often helps to produce more tubers. 

Planting should be early in the spring, when the soil can be satisfactorily worked. Later planting results in reduced yields. Whole tubers or pieces of tubers that are no less than two ounces and have two or three prominent buds should be planted. Smaller seed pieces will reduce yields but larger seed pieces (over 2 oz) will not significantly increase them. Do not allow cut seed pieces to dry before planting. Plant 3 to 5 inches deep, in rows 36 to 42 inches wide with 15 to 24 inches between plants.

Cultivate shallowly and only as needed to control grass and weeds as the planting is being established. During plant establishment, grass and weed problems will be reduced by shading since plants grow over 6 ft high. Tubers begin to form in August and may become 4 inches long and 2 to 3 inches in diameter.

The crop should not be harvested until after frost. Tubers dug later in the season are sweeter but have less inulin. Tops should be cut with a mower. Plow open the furrow, pick up the tubers, place in field containers, and remove from the field. Hand rakes can be used to great advantage in locating the tubers. Because of their small size it is necessary to use a small, modified potato harvester to mechanically harvest the tubers.

The skin of the chokes is very thin. Care should be taken in handling to avoid skinning, cuts and bruises. The skin is also susceptible to rapid moisture loss so the crop should be put in storage immediately after harvest. Cold storage facilities should have high humidity (85 to 95% relative humidity) and a temperature near 32 0F. Under these conditions, tubers can be kept for several months. If the tubers are to be washed, fresh water sanitized with bleach should be used.

I usually store them in Ziploc plastic bags with a moistened paper towel on top of them. 

There is considerable variation in yields but generally growers may expect from 5 to 7 tons per acre.

Please keep in mind that all you have to do is plant them once because they are a wee bit invasive. You will never be able to get every tuber and every rhizome out and the plant will reseed itself. You of course can control this by burying edge treatments to keep them contained into a certain area or plant them in very large potted containers. The pollinators love these flowers and are all over them and once you get used to tasting sunchokes you will too. Some of the restaurants we sell them to primarily make Jerusalem artichoke soup or do a 50-50 mash mixing them with potatoes. I personally like them as a replacement for water chestnuts in my stirfries and baked Jerusalem artichoke chips are now the rave.