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Siberian peashrub

Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.

  1. Uses
  2. Folk Medicine
  3. Chemistry
  4. Description
  5. Germplasm
  6. Distribution
  7. Ecology
  8. Cultivation
  9. Harvesting
  10. Yields and Economics
  11. Energy
  12. Biotic Factors
  13. References

Uses

"During World War II, the Siberian peasants reportedly carried their chicken flocks through the winter feeding the seed of one small woody pland, Caragana arborescens." (Snell, 1983). Some ethnic groups have used young pods for vegetables. Seeds serve as a valuable wild life food. Bark provides a fiber. Leaves yield an azure dye. Because of its cold and drought tolerance, it is widely planted in the US and Canada for windbreaks. In the northern Great Plains, it is also used for hedges and outdoor screening. Because of its nitrogen-fixing capacity, it is valued as a soil-improving plant. In the Arctic Circle it is valued as a supplementary fodder for reindeer herds. It is valuable in these colder climates, but in warmer climates like New England as the eastern and western coastal areas of the US, better ornamentals are available. According to Snell (1983), Caranga "serves well as a windbreak, ground cover, soil builder, poultry cover, cattle forage, vegetable for human use, fiber plant, bee plant, dye plant, and ornamental landscape specimen."

Folk Medicine

According to the Dictionary of Chinese Traditional Medicine (Kiangsu, 1977), the whole plant, known as ning tiao, is used for cancer of the breast, and the orifice to the womb, and for dysmenorrhea and other gynecological problems.

Chemistry

According to USDA analyses, the ash content of the seed runs 3.4-3.6, protein 35.5-36.4%, oil content 13.2-13.6%. Contains a lectin or phytohemagglutinin.

Description

Deciduous shrub or small tree 6-8 m tall; stipules becoming spiny, leaves alternate, paripinnate, 5-9 cm long, with 3-6 pairs of obovate to elliptic-oblong leaflets, to 2.5 cm long. Flowers yellowish, pea-shaped, one to four in each cluster, the calyx teeth short, as broad as long. Fruit stalked to 5 cm long, with 6 reddish-brown, oblong to spherical seeds, 2.5-4 0 mm in diam. (Seeds ca 40,000-42,000/kg).

Germplasm

Reported from the Eurosiberian Center of Diversity, Siberian peashrub is reported to tolerate alkalinity, drought, cold, poor soil, and wind. Some named variations are forma xorbergii, var. crasseaculeata, var. nana, and var. pendula, the latter with handsome drooping branches. (2n = 16)

Distribution

Native to Siberia and Manchuria. Extends over about 160 million ha in Siberia 77deg.-120deg. E, 48deg.-60deg. N. In the US its growth is stunted south of Nebraska.

Ecology

Apparently ranges from Cold Temperate Steppe to Moist through Boreal Moist to Wet Forest Life Zones, Siberian peashrub tolerates annual precipitation of 4 to 8 dm, annual temperature of 2 to 7°C reaching Zone 2 (Hardiness Zone) of the United States and Canada.

Cultivation

According to Hortus III (1976), pea trees grown for their flowers should be planted in.sunny locations in sandy soil. Seeds are generally sown outdoors in autumn, or in spring after soaking the seed in warm water. Softwood cuttings can be set in early June. Also propagated by root cuttings, layering, or grafting. Certain pesticides, captain, thiram, and mercuric chlorate can increase germination, possibly by inhibiting disease. No significant differences in characteristics of 1-year-old seedlings were noted following Rhizobia inoculation of seeds prior to field sowing. However, one source recommended inoculation for best results. Many nurserymen recommend planting 75-150 seeds per linear meter. A Russian report recommended planting 2.5 cm deep. In one North Dakota nursery, Siberian peashrub is seeded during the last week in July or the first week in August. A cover crop of oats is seeded between the tree rows early enough to give winter protection. Shrubs are large enough to dig the following fall (Ag Handbook 450).

Harvesting

In the US, the optimum time for collecting seed is less than two weeks, usually in July or August. Since seeds are ready to collect as soon as the fruit ripens, the pods should be gathered by hand as soon as they open. For vegetable trials, greener pods should of course be harvested.

Yields and Economics

Shrubs take ca 3-5 years to reach commercial bearing age (Ag Handbook 450). Good crops occur nearly every year.

Energy

With no data available, I speculate that this species could produce 4-10 MT/DM/yr fixing nitrogen in the process. Nitrogen-fixing rhizobia were reported in the species before 1900. There is considerable variation in the 14 strains now reported, all belonging to the slow-growing cowpea-soybean-lupine type rhizobia. Host infective patterns were quite uniform but some nonreciprocal cross-inoculation was observed. Caragana rhizobia reisolated from nodules they formed on Trifolium pratense retained the ability to nodulate Caragana. Throughout the life of a Caragana nodule, the volume of tissue functionally active in N-fixation remains more or less constant. As the nodule becomes larger, the ratio of the N-fixing volume to total nodule mass becomes smaller. On a one-month-old nodule, the ratio of functional bacteroidal tissue to total nodule mass is about 1:1, in 2-month-olds, 1:2; in 6-month-olds 1:5. Of particular interest is the coexistence of juvenile and senescent tissue in close proximity for long periods. Growth equilibrium, development, and function of the nodule, do not appear unbalanced during its existence (Allen and Allen, 1981).

Biotic Factors

Agriculture Handbook 165 lists: Agrobacterium rhizogenes (hairy root), Ascochyta sp. (leaf blight), Botrytis cinerea (pod blight), Cucurbitaria anae (on branches), Hendersonia septem-septata (on twigs), Pellicularia filamentosa (root rot of seedlings), Phomopsis caraganae and Phomopsis rudis (on branches), Phyllosticta gallarum (leaf spot), Phymatotrichum omnivorum (root rot), Phytophthora cactorum (wilt of seedlings), Rhizoctonia solani (damping-off), Septoria sp. (leaf blight), and Sphaeropsis sp. (on branches). Nursery stock may need pesticides to prevent damage by spiders, blister beetles, and other leaf-eating insects. Grasshoppers are especially destructive, sometimes completely defoliating the plants. Plants have also been extensively damaged by browsing deer, but mammal repellent has been effective (Ag Handbook 450).

References

Complete list of references for Duke, Handbook of Energy Crops
Last update July 3, 1996