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Populus deltoides Bartr. ex Marsh.

Salicaceae
Eastern cottonwood

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 unpublished.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

The timber is used principally for lumber, veneer, pulpwood, excelsior, and fuel (Laver, 1981). Widely used in the US and Canada for shelterbelt and amenity plantings (Ag. Handbook 450). Recently, it has been championed as one of the leading potential species for silviculture biomass production. Salicylic acid, derivable from this species, is now synthesized and selling at ca $2.50 to $3.00 per kilo. Salicylic acid in technical form is used as a coupling agent in dye intermediates, in the foundry industry as a curing agent in the production of shell molding compounds, as an agent for retarding the vulcanization process in rubber, as a preservative for glues and leather goods, and in alkyl/alkyd resins and latex paints (CMR, Dec. 13, 1982).

Folk Medicine

The bark tincture has been used to treat rheumatism, gout, and scurvy and infections of the chest, kidneys, and stomach. The buds have been used as a vulnerary and pectoral. In Europe, the fresh flowers are steeped in cold water to purify the blood. Used by Amerindians as a folk cancer remedy. Ojibwa used aspen buds, stewed in bear fat, for earache, bronchitis, or cough. Bella Coola decocted the rotten leaves as an herbal bath for general body pain and used the buds in poultices for hip or lung pain. Carrier chewed the root to apply as a hemostat and decocted the buds for colds and respiratory problems. Chippewa decocted the buds for colds and respiratory problems; heart ailments, sprains, and strains, and the root for backache, female problems, metrorrhea, and weakness. Delaware used the bark for female ailments. Nanticoke used bark for sprains. Ojibwa used the down like cotton on wounds. Potawatomi cooked buds in tallow to make an ointment for eczema and sores. "Tacamahaca" was used by Amerindians for maturing tumors. Smoky Mountain settlers used the buds like the Indians to make a salve for myalgia and soreness (Duke, 1983c).

Chemistry

The bark contains salicortin, salicin, salicyl alcohol, pyrocatechin, a-salicyloylsalicin, grandidentatin, grandidentoside, populoside, trichocarposide, and 6-methyldihydroquercetin. Leaves contain salicortin, salicin, salicyl alcohol, pyrocatechin, 1-0-p-cumaroyl-b-D-glycoside, populoside, a-salicyloylsalicin, chrysin-7-glucoside, and deltoidin (2-0-salicyloylsalicin). Tremulacin, brenzcatechin, and quercetin-3,3'-dimethyethes are also reported (List and Horhammer, 1969–1979).

Description

Large tree to 20–30(-50) m tall, diam. 0.5 to 2 m; bark grayish-green and smooth at first, later blackish and furrowed. Leaves broadly deltoid, 8–15 cm long, nearly as broad, glabrous on both sides, short-acuminate, dentate with incurved glandular or callous tipped teeth; bases truncate to subcordate, with 2–3 basal glands; petiole strongly flattened laterally. Bracts of aments fringed or fimbriate, the divisions narrow. Staminate aments 7.5–12.5 cm long, thick, stamens ca 60 or more, anthers red. Pistillate aments green and slender, 2–3 dm long; ovaries glabrous; stigmas 3 or 4. Capsules ovoid, 6–10 mm long, glabrous, green, the peduncle 3–10 mm long; seeds cottony (Brown and Brown, 1972).

Germplasm

Reported from the North American Center of Diversity, eastern cottonwood, or cvs thereof, is reported to tolerate frost, heavy soil, sand, slope, and waterlogging. Because of its intolerance to competition and the absence of suitable seedbeds under existing stands, it does not usually succeed itself (Laver, 1981).

Distribution

Quebec to North Dakota, south to Florida and Texas (Ag. Handbook 450).

Ecology

Estimated to range from Warm Temperate Dry to Moist through Cold Temperate Dry to Moist Forest Life Zones, eastern cottonwood is reported to tolerate annual precipitation of 6 to 15 dm, annual temperature of 8 to 14°C, and pH of 4.5 to 8. Said to persist on infertile sands, fine sandy loams, and fairly stiff clays, but thrives on moist well-drained, fine sandy loams or silts close to streams (Laver, 1981).

Cultivation

Seeds are microbiotic, but,with proper drying and cold storage in sealed containers, their viability can be maintained for several years. Natural seed regeneration can be obtained on moist sites with exacting site preparation. Seed should not be covered nor pressed into the soil of the seedbed. Young seedlings are very susceptible to drying out, and the seedbed must be kept water-saturated for germination and at least one month thereafter (ca 1 oz seed per 100 ft2 seedbed; or about 300 seeds per sq ft) for broadcast, 100 seeds per linear foot for drilling. About 4 weeks after germination, beds should be thinned to 20 plants per square foot. Nursery beds are often stream sterilized or fumigated with methyl bromide to help control damping off. Finely divided sphagnum moss is a good medium for culturing poplar seedlings in the greenhouse (Ag. Handbook 450).

Harvesting

In the Lower Mississippi Valley, seed ripening and dispersal takes place from mid-May through late August, while in the Northeastern US, it occurs slightly later. Cottonwoods produce large seed crops nearly every year.

Yields and Economics

Geyer studied two provenances of cottonwood germplasm, one from Missouri, the other from Nebraska. At Tuttle Creek, Kansas (Eudora soil series, silty-clay loam, pH 7.5, 2.0% organic matter, 146 kg available P/ha, 560 kg exchangeable kg/ha; annual precipitation 838 mm, annual mean temperature 13°C) the Missouri germplasm produced 24,000 kg/ha ovendry biomass over four years spaced at 0.3 by 1.2 m, 29,400 kg/ha spaced at 0.6 by 1.2 m, and 27,100 kg/ha spaced at 1.2 by 1.2 m. This averages out to annual biomass production of 6 MT/ha at 0.3 by 1.2, 7 MT/ha at 0.6 by 1.2, and 7 MT/ha at 1.2 by 1.2 m. At the sandier Milford site (cass fine sandy loam, pH 7.7, 0.6% organic matter, 22 kg P and 336 kg K; annual precipitation 787 mm, the Missouri germplasm produced 22,000 kg/ha ovendry biomass spaced at 0.3 by 1.2 m, 20,600 kg/ha spaced at 0.6 by 1.2, and 21,100 kg/ha spaced at 1.2 by 1.2. Annual biomass production (aboveground) thus averages out to about 6 MT/ha at 0.3 by 1.2, 5 MT/ha at 0.6 by 1.2, and 5 MT/ha at 1.2 by 1.2 m. Biennial harvests were made in December when no leaves were on the trees. The stumps sprouted vigorously the following spring. Bark accounted for about 28% of the small parts of the tree on a dry weight basis, 16% of the large parts, running about 19% for the whole tree. The heat of combustion for the small parts was 4,695 cal/g, 4,416 for the large parts. At Tuttle Creek, the Nebraska germplasm produced 27,400 kg/ha ovendry biomass over four years spaced at 0.3 by 1.2 m, 25,800 kg/ha spaced at 0.6 by 1.2 m, and 28,000 kg/ha spaced at 1.2 by 1.2 m, averaging 7 MT/ha/yr at 0.3 by 1.2, 6 MT at 0.6 by 1.2 and 7 MT at 1.2 by 1.2 m. At the sandier Milford site, the Nebraska germplasm produced 28,200 kg/ha ovendry biomass spaced at 0.3 by 1.2 m, 28,500 kg/ha spaced at 0.6 by 1.2, and 24,000 kg/ha spaced at 1.2 by 1.2 averaging out to about 7 MT/ha/yr at 0.3 by 1.2, 7 MT at 0.6 by 1.2, and 6 MT at 1.2 by 1.2 m. Bark accounted for about 41% of the small parts of the tree on a dry weight basis, 23% of the large parts, running about 28% for the whole tree. The heat of combustion for the small parts was 4,385 cal/g, 4,288 for the large parts. Average annual of several species tested in eastern Kansas ran from 3.6 to 6.7 ovendry MT/ha, with close spacings producing the greatest tonnage, greater than those reported from similar studies in southeastern and northeastern US. Geyer compares these studies with similar studies in Pennsylvania, spaced at 0.6 by 0.6 m, yielding 0.6 MT/ha in year 1, 3.7 in year 2, 6.0 in year 3, and 6.2 in year 4. Another Kansas study showed 5.8 MT/ha/yr in 3 year old Populus 'Tristis No. l' (Geyer, 1981). Henry and Salo (1981) calculate the energetic cost of a silvicultural biomass farm as 1.67 billion (109) Btu for supervision, 0.53 for field supply, 7.87 for harvesting, 8.78 for handling the biomass, 17.32 for transport of the biomass, 112.48 for irrigation, 128.33 for fertilizaton and cultivation for a total consumption of ca 277 109 Btu, returning 4,250 x 109 Btu as energy, for a net gain of 3,972 x 109 Btu. (For a farm designed to have an annual production of 250,000 ovendry tons of biomass, enough to support an electric power plant of ca 50 MW.)

Energy

According to the phytomass files (Duke, 1981b), annual productivity in Populus ranges from 3 to 22 MT/ha. Fast growing poplars in Sweden, harvested young, have given biomass yields of 14–28 MT/ha. The maximum possible production of fast growing poplars, with optimum fertilization and moisture, is 44 MT/ha in the Netherlands, but normal production levels are closer to 6 (Palz and Chartier, 1980). The MAI of ca 22 MT DM/ha have been reported for hybrid poplars in Sweden, Henry and Salo (1981) assume that silvicultural energy farms in Louisiana will generate 15.3 times as much energy as they consume, compared to 10.6 times in Wisconsin. Here we see the 10:1 ratio we saw also in oilseeds, much higher than the average energetic yields for conventional crops.

Biotic Factors

Agriculture Handbook No. 165 lists the following as affecting this species: Agrobacterium tumefaciens, Cercospora populina, C. populicola, C. reducta, Ciborinia confundens, Cryptodiaporthe salicina, Dothichiza populea, Fomes applanatus, F. igniarius, Graphium rubrum, Hypoxylon spp., Marssonina populi, Melampsora abietis-canadensis, M. medusae, M. occidentalis, Melanconis occulta, Mycosphaerella macularis, M. populifolia, M. populorum, Nectria sp., Phoradendron flavescens var. macrophyllum, Phyllosticta intermixta, P. maculans, Phymatotrichum omnivorum, Physalospora obtusa, Pleurotus ostreatus, Polyporus spp., Septoria populi, S. populicola, Steccherinum ochraceum, Stigmina sp. Taphrina aurea, T. johansonii, Trametes hispida, Uncinula salicis, Valsa nivea, V. sordida, Venturia tremulae. In addition, Browne (1968) lists the following as affecting this species: Bacteria: Aplanobacter populi. Fungi: Armillaria mellea, Cladosporium subsessile, Cryptodiaporthe populea, Drepanopeziza populorum, D. punctiformia, Fomes fomentarius, Ilypoxylon pruinatum, Leucostoma niveum, Melampsora laricipopulina, M. populnea, Mycosphaerella populorum, Nectria coccinea, N. ditissima, N. galligena, N. haematococca, Neofabraea populi, Oxyporus populinus, Pezicula populi, Phellinus igniarius, Phyllosticta populina, Septotinia populiperda, Trametes sauveolens, Venturia macularis. Coleoptera: Capnodis miliaris, Chrysomela interrupta, C. scripta, Tragocephala variegata, Zeugophora abnormis, Z. scutellaris. Diptera: Phytagromyza populicola. Hemiptera: Pemphigus populitransversus, Phloemyzus passerini. Hymenoptera: Pontania bozemani, Trichiocampus viminalis. Lepidoptera: Acronicta lepusculina, Choristoneura conflictana, Leucoma salicis, Nymphalis antiopa, Paranthrene tabaniformis, Sesia tibialis. Mammalia: Capra hircus, Oryctolagus cuniculus (Browne, 1968). Adults and larvae of the cottonwood leaf beetle (Chrysomela scripta) feed on the foliage and succulent stems of seedlings, killing or retarding growth in plantations and nurseries. Equally injurious are cottonwood twig borers (Gypsonoma haimbachiana) and cotton root and stem borers (Paranthrene dollii). Borers of the southern and central states (Plectrodera scalator) and the poplar borer (Saperda calcarata), found principally in the northern part of the range, cause lumber defects (Laver, 1981).

References

Complete list of references for Duke, Handbook of Energy Crops
Last update January 8, 1998 by aw