Jerusalem Artichoke Association of Canada
Disease, Insects and their control
Relative to other crops, the Jerusalem artichoke has few serious pest and disease problems. However, severe yield reduction can occur when fungal or bacterial infestation affect the tubers. A few disease have been reported to affect the Jerusalem artichoke. Sclerotinia (white mold) is the primary disease that affect dry edible bean, sunflower and soybean but also that wilt, degradation of tubers and rot the stalks of Jerusalem artichokes. All susceptible crops should be rotated with small grains or corn. Close rotations with dry edible beans, sunflower, safflower and mustard, soybeans should be avoided. Downy mildew, rust and southern stem light have also been reported although these are not of economic concern. There are currently no labeled fungicides for Jerusalem artichokes.
As aforementioned, insects have not been a serious problem although the potential is greater on larger plantations. Stem boring insects have been reported but have not caused important damage. Currently there are no registered insecticides for Jerusalem artichokes.
Storage rots appear to be a serious problem for Jerusalem artichokes. These can be controlled by storing the tubers at 0 to 2C, removal of diseased tubers and by minimizing mechanical damage and controlling the relative humidity (optimum 90-95%). At lower relative humidity, the tubers tend to shrivel and are more likely to decay.
Jerusalem artichoke is a very competitive plant. To reduce emerging weeds, an early season cultivation is recommended with a tillage operation to improve hilling of rows. Currently, there are no registered herbicides for use in Jerusalem artichoke. Tubers over-winter very well in the soil. Thus volunteer Jerusalem artichokes can be a serious weed problem for other crops. It can spread into other crops and even grow taller than corns. Tillage operations after tubers have exhausted their food supply and before new tubers begin to form, significantly retard the spread of Jerusalem artichoke. Roundup® (glyphosate) is an herbicide that can be used to get rid of volunteer Jerusalem artichoke. 2,4-D and Banvel® are also used to control the spread of Jerusalem artichoke.
Cultivation of Jerusalem artichokes
Growth habits and environment requirements
Native to temperate regions of North America, Jerusalem artichokes (Helianthus tuberosus) can tolerate an annual precipitation of 31 to 282 cm, and an average temperature of 6.3 to 26.6°C and pH of 4.5 to 8.2. Jerusalem artichokes can adapt to a wide range of soil types and pH levels in a sunny position but slightly alkaline soils are favorable for the production of tubers. Because of their thin skin, the tubers can easily be damaged when harvested, thus lighter well-drained sandy loams are more suitable for their growth, although plants tend to be more productive when grown in a rich soil. Jerusalem artichokes are particularly suited to dry regions and poor soils, have more yield of tubers than potatoes. The plant can tolerate sub-zero temperature while tubers can survive freezing temperatures for several months even if the frost kills the stems and leaves. The cold tolerant nature of tubers allow them to be preserved in the ground during the cold winter until harvest. Helianthus tuberosus require longer periods of light from seedling to maturation and shorter periods for the formation of tubers in summer, since they are sensitive to day-length hours. For optimal production of tubers, the plant is planted in early spring to a depth of 10-15 cm. The seed tubers are spaces 30-60 cm apart in each row with rows 45-120 cm apart. The optimal soil temperature for planting is 6-7°C since tubers are dormant at cold temperature below 5°C. Jerusalem artichokes are usually planted in well-drained soil slightly alkaline. Irrigation is not normally needed and the plant is ready to be harvested in 125 days. Although Jerusalem artichoke are thought to grow well in marginal soils, tuber and top yields are limited when soil moisture is less than 30% of the field capacity during period of tuber formation (early September to November). Thus, it is sometimes necessary to irrigate for seed germination and tuber production in dry areas. On the other hand, yields tend to be poor on heavy clays particularly if there is waterlogging - the crop does not appear to grow abundantly in poorly drain soils. H. Tuberosus are considered to be moderately tolerant to salinity; they could be safely grown in salt-affected land with 25-50% seawater irrigation. The yield is poorly on peat soils in Quebec. Tubers that are planted in loose sandy loam soil produce adequately and loose soil allow easy harvest.
After planting, tubers sprout in about 10 to 17 days, the soil temperature must be at least 6-7°C before germination begins. Jerusalem artichokes are propagated using small tubers or pieces of tubers weighing about 55 g and having 2-3 buds each. Pieces of tuber are cut to approximately 1-2 oz in size. Planting depths are similar to potatoes – covered by 2 to 4 inch of soil. Hilling is also practiced to increase the retention of moisture and to concentrate tubers to enable easy harvest.