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Dr. Udo Blum
Professor Emeritus
Research
Interests:
I am presently
interested in characterizing and identifying the mechanisms
by which allelopathic compounds, specifically phenolic
acids (e.g., ferulic acid, p-coumaric acid, vanillic acid,
p-hydroxybenzoic acid), released into the soil environment
may impact soil chemistry (e.g., soil nutrition, organic
pools, sorption and desorption), soil microbiology (e.g.,
population biology, natural selection, carbon utilization),
rhizosphere ecology (e.g., microbial population biology)
and population biology (e.g., germination, seedling emergence)
and physiology (e.g., mineral nutrition, carbon allocation,
water relations, growth) of dicot weeds in no-till agroecosystems.
Publications:
Blum,
U., and Rice, E. L. 1969. Inhibition of symbiotic nitrogen-fixation
by gallic and tannic acid, and possible roles in old-field
succession. Torrey Bot. Club 96 : 531-544.
Tingey,
D. T., and Blum, U. 1973. Effects of ozone on soybean nodules.
J. Environ. Qual. 2:341-342.
Akers, S. W., Anderson, C. E., and Blum, U. 1977. Characterization
of vacuolar bodies in Spartina alterniflora: I. Formation,
development, morphology, and ultrastructure. Amer. J. Bot.
64:635-640.
Akers,
S. W., Anderson, C. E., and Blum, U. 1977. Characterization
of vacuolar bodies in Sparatina alterniflora: II. Some
physical and chemical properties. Amer. J. Bot. 64:641-648.
Blum,
U., and Tingey, D. T. 1977. A study of the potential ways
in which ozone could reduce root growth and nodulation of
soybean. Atmospheric Environ. 11:737-739.
Letchworth,
M. B., and Blum, U. 1977. Effects of acute ozone exposure
on growth, nodulation and nitrogen content of ladino clover.
Environ. Pollut. 14:303-312.
Blum, U., Seneca, E. D., and Stroud, L. M. 1978. Photosynthesis
and respiration of Spartina and Juncus salt marshes in North
Carolina: Some models. Estuaries 1:228-238
Blum,
U., and Heck, W. W. 1980. Effects of acute ozone exposures
on snap bean at various stages of its life cycle. Environ.
Exp. Bot. 20:73-85.
Conn, J. S., Wentworth, T. R., and Blum, U. 1980. Pattern
of dioecism in the flora of the Carolinas. Amer. Midl. Natur.
103:310-315.
Kochhar, M., Blum, U., and Reinert, R. A. 1980. Effects
of O3 and (or) fescue on ladino clover: interactions.
Can. J. Bot. 58:241-249.
Conn,
J. S., and Blum, U. 1981. Differentiation of the sexes
of Rumex hastatulus in net energy allocation, flowering
and height. Torrey Bot. Club. 108:446-455.
Conn, J. S., and Blum, U. 1981. Sex ratio of Rumex hastatulus:
the effects of environmental factors and certation. Evolution
35:1108-1116.
Linthurst, R. A., and Blum, U. 1981. Growth modification
of Spartina alterniflora Loisel. by the interaction of pH
and salinity under controlled conditions. J. Exp. Mar. Biol.
Ecol. 55:207-218.
Blum, U., Smith, G. R., and Fites, R. G. 1982. Effects
of multiple O3 exposures on carbohydrate and mineral contents
of ladino clover. Environ. Exp. Bot. 22:143-154.
Cammen,
L. M., Blum, U., Seneca, E. L., and Stroud, L. M. 1982.
Energy flow in a North Carolina salt marsh: A synthesis
of experimental and published data. ASB. Bulletin 29:111-134.
Hall, A. B., Blum, U., and Fites, R. C. 1982. Stress modification
of allelopathy of Helianthus annuus L. debris on seed
germination. Amer. J. Bot. 69:776-783.
Montes,
R. A., Blum, U., and Heagle, A. S. 1982. The effects of
ozone and nitrogen fertilizer on tall fescue, ladino clover,
and a fescue-clover mixture. I. Growth, regrowth and forage
production. Can. J. Bot. 60:2745-2752.
Kochhar,
M., Reinert, R. A., and Blum, U. 1982. Effects of Festuca
arundinacea and/or clover Trifolium repens debris and fescue
leaf leachate on clover as modified by 03 and Rhizoctonia
solani. Environ. Pollution 28:255-264.
Blum, U., Heagle, A. S., Burns, J. C., and Linthurst, R.
L. 1983. The effects of ozone on fescue-clover forage:
Regrowth, yield and quality. Environ. Exp. Bot. 23:121-132.
Blum, U., Mrozek, E., Jr., and Johnson, E. 1983. Investigation
of ozone (O3) effects on 14C distribution in ladino clover.
Environ. Exp. Bot. 23:369-378.
Dalton,
B. R., Blum, U., and Weed, S. B. 1983. Allelopathic substances
in ecosystems: Effectiveness of sterile soil components
in altering recovery of ferulic acid. J. Chem. Ecol. 9:1185-1201.
Hall,
A. B., Blum, U., and Fites, R. C. 1983. Stress modification
of Helianthus annuus L. debris on seedling biomass production
of Amaranthus retroflexus L. J. Chem. Ecol. 9:1213-1222.
Montes,
R. A., Blum, U., Heagle, A. S., and Volk, R. J. 1983. The
effects of ozone and nitrogen fertilizer on tall fesuce,
ladino clover, and a fescue-clover mixture. II. Nitrogen
content and fixation. Can. J. BOt. 61:2159-2168.
Kochlar,M., Reinert, R.A., and Blum, U. 1982. Effects of Festuca arundinacea and /or clover Trifolium repens debris and fescue leaf leachate on clover as modified by 03 and Rhizoctonia solani. Environ. Pollution 28:255-264.
Blum,
U., Dalton, B. R., and Rawlings, J. O. 1984. Effects of
ferulic acid and some of its microbial metabolic products
on the radicle growth of cucumber. J. Chem. Ecol. 10:1169-1191.
Seneca, E. D., and Blum, U. 1984. Response to photoperiod
and temperature by Spartina alterniflora (Poaceae) from
North Carolina and Spartina foliosa from California. Amer.
J. Bot. 71:91-99.
Blum, U., and Dalton, B. R. 1985. Effects of ferulic acid,
an allelopathic compound, on leaf expansion of cucumber
seedlings grown in nutrient culture. J. Chem. Ecol. 11:279-301.
Blum, U., Dalton, B. R., and Shann, J. R. 1985. Effects
of various mixtures of ferulic acid and some of its microbial
metabolic products on cucumber leaf expansion and dry
matter in nutrient culture. J. Chem. Ecol. 11:619-641.
Blum,
U., Dalton, B. R., and Shann, J. R. 1985. Effects of ferulic
and p-coumaric acids in nutrient culture on cucumber leaf
expansion as influenced by pH. J. Chem. Ecol. 11:1567-1582.
Blum,
U., Weed, S. B., and Dalton, B. R. 1987. Influence of various
soil factors on the effects of ferulic acid on leaf expansion
of cucumber seedlings. Plant and Soil 98:111-130.
Dalton,
B. R., Weed, S. B., and Blum, U. 1987. Plant phenolic acids
in soils: A comparison of extraction procedures. Soil Sci.
Soc. Amer. J. 51:1515-1521.
Johnson,
E. L., Heck, W. W., Fites, R. C., and Blum, U. 1987.
Effects of irradiance on amino and organic acid levels
in ladino clover. Environ. Expt. Bot. 27:441-448.
Shann, J. R., and Blum, U. 1987. The uptake of ferulic and
p-hydroxybenzoic acids by Cucumis sativus. Phytochemistry
26 : 2959-2964.
Shann, J. R., and Blum, U. 1987. The utilization of exogenously
supplied ferulic acid in lignin biosynthesis. Phytochemistry
26:2977-2982.
Waters, E. R., and Blum, U. 1987. The effects of single
and multiple exposures of ferulic acid on the vegetative
and reproductive growth of Phaseolus vulgaris BBL-290.
Amer. J. Bot. 74:1635-1645.
Blum, U., and Shafer, S. R. 1988. Microbial populations
and phenolic acids in soils. Soil Biol. Biochem. 20:793-800.
Rebbeck,
J., Blum, U., and Heagle, A. S. 1988. Effects of ozone on
the regrowth and energy reserves of a ladino clover-tall
fescue pasture. J. Applied Ecol. 25:659-681.
Blum, U., Gerig, T. M., and Weed, S. B. 1989. Effects of
mixtures of phenolic acids on leaf area expansion of cucumber
seedlings grown in different pH Portsmouth A1 soil materials.
J. Chem. Ecol. 15:2413-2423.
Blum, U., and Rebbeck, J. 1989. The inhibition and recovery
of cucumber roots given multiple treatments of ferulic acid
in nutrient culture. J. Chem. Ecol. 15:917-928.
Booker,
F. L., Seneca, E. D., and Blum, U. 1989. Effects of weathered
fuel oil on solute leakage, respiration and plasmolysis
in excised root sections of Spartina alterniflora Loisel.
and Limonium carolinianum (Walt.) Britt. Environ. Expt.
Bot. 29:249-259.
Dalton,
B. R., Blum, U., and Weed, S. B. 1989. Differential sorption
of exogenously applied ferulic, p-coumaric, p-hydroxybenzoic,
and vanillic acids in soil. Soil Sci. Soc. Amer. J. 53:757-762.
Dalton,
B. R., Blum, U., and Weed, S. B. 1989. Plant phenolic acids
in soils: Sorption of ferulic acid by soil and soil components
sterilized by different techniques. Soil Biol. Biochem.
21:1011-1018.
Gerig, T. M., Blum, U., and Meier, K. 1989. Statistical
analysis of the joint inhibitory action of similar compounds.
J. Chem. Ecol. 15:2403-2412.
Heagle, A. S., Rebbeck, J., Shafer, S. R., Blum, U., and
Heck, W. W. 1989. Effects of long-term ozone exposure and
soil moisture deficit on growth of a ladino clover-tall
fescue pasture. Phytopathology 79:128-136.
White,
R. H., Worsham, A. D., and Blum, U. 1989. Allelopathic potential
of legume debris and aqueous extracts. Weed Science 37:674-679.
Klein,
K., and Blum, U. 1990. Inhibition of cucumber leaf expansion
by ferulic acid in split-root experiments. J. Chem. Ecol.
16 : 455-463.
Klein, K., and Blum, U. 1990. Effects of soil nitrogen level
on ferulic acid inhibition of cucumber leaf expansion. J.
Chem. Ecol. 16:1371-1383.
Lyu, S.-W., Blum, U., Gerig, T. M., and O'Brien, T. E. 1990.
Effects of mixtures of phenolic acids on phosphorus uptake
by cucumber seedlings. J. Chem. Ecol. 16:2559-2567.
Lyu, S.-W., and Blum, U. 1990. Effects of ferulic acid,
an allelopathic compound, on net P, K, and water uptake
by cucumber seedlings in a split-root system. J. Chem. Ecol.
16:2429-2439.
Blum,
U., Wentworth, T. R., Klein, K., Worsham, A. D., King, L.
D., Gerig, T. M., and Lyu, S.-W. 1991. Phenolic acid content
of soils from wheat-no till, wheat-conventional till, and
fallow-conventional till soybean cropping systems. J. Chem.
Ecol. 17:1045-1068.
Gerig,
T. M., and Blum, U. 1991. Effects of mixtures of four phenolic
acids on leaf area expansion of cucumber seedlings grown
in Portsmouth B1 soil materials. J. Chem. Ecol. 17:29-40.
Holappa, L. D., and Blum, U. 1991. Effects of exogenously
applied ferulic acid, a potential allelopathic compound,
on leaf growth, water utilization, and endogenous abscisic
acid levels of tomato, cucumber, and bean. J. Chem. Ecol.
17:865-886.
Hollingworth, R. G., Blum, U., and Hain, F. P. 1991. The
effects of adelgid-altered wood on sapwood conductance of
fraser fir Christmas trees. IAWA Bull. 12:235-239.
Shafer, S. R., and Blum, U. 1991. Influence of phenolic
acids on microbial populations in the rhizosphere of cucumber.
J. Chem. Ecol. 17:369-389.
Bergmark, C. L., Jackson, W. A., Volk, R. J., and Blum,
U. 1992. Differential inhibition by ferulic acid of nitrate
and ammonium uptake in Zea mays L. Plant Physiology 98:639-645.
Blum,
U., Gerig, T. M., Worsham, A. D., Holappa, L. D., and King,
L. D. 1992. Allelopathic activity in wheat-conventional
and wheat-no-till soils: Development of soil extract bioassays.
J. Chem. Ecol. 18:2191-2221.
Booker,
F. L., Blum, U., and Fiscus, E. L. 1992. Short-term effects
of ferulic acid on ion uptake and water relations in cucumber
seedlings. J. Expt. Bot. 43:649-655.
Blum,
U., Gerig, T. M., Worsham, A. D., and King, L. D. 1993.
Modification of allelopathic effects of p-coumaric acid
on morning-glory seedling biomass by glucose, methionine,
and nitrate. J. Chem. Ecol. 19:2791-2811.
Gerig,
T. M., and Blum, U. 1993. Modification of an inhibition
curve to account for effects of a second compound. J. Chem.
Ecol. 19:2783-2790.
Blum, U., Worsham, A. D., King, L. D. and Gerig, T. M.
1994. Use of water and EDTA extractions to estimate available
(free and reversibly Bound) phenolic acids in Cecil soils.
J. Chem. Ecol. 20:341-359.
Lehman, M. E., Blum, U., and Gerig, T. M. 1994. Simultaneous
effects of ferulic and p-coumaric acids on cucumber leaf
expansion in split-root experiments. J. Chem. Ecol. 20:1773-1782.
Pue,
K. J., Blum, U., Gerig, T. M., and Shafer, S. R. 1995. Mechanism
by which non inhibitory concentrations of glucose increase
inhibitory activity of p-coumaric acid on morning-glory
seedling biomass accumulation. J. Chem. Ecol. 21:833-847.
Blum, U. 1996. Allelopathic interactions involving phenolic
acids. J. Nematology 28:259-267.
Blum, U. 1997. The benefits of citrate over EDTA for extracting
phenolic acids from soils and plant debris. J. Chem. Ecol.
23:347-362.
Blum, U., King, L. D., Gerig, T. M., Lehman, M. E., and
Worsham A. D. 1997. Effects of clover and small grain cover
crops and tillage techniques on seedling emergence of some
dicotyledonous weed species. Amer. J. Alternative Agriculture.
12:146-161.
Lehman,
M. E. and Blum, U. 1997. Cover crop debris effects on weed
emergence as modified by environmental factors. Allelopathy
J. 4:69-88.
Blum, U. 1998. Effects of microbial utilization of phenolic
acids and their phenolic acid breakdown products on allelopathic
interactions. J. Chem. Ecol. 24:685-708.
Shafer, S. R., Blum, U., Horton, S. J., and Hesterberg,
D. L., 1998. Biomass of tomato seedlings exposed to an allelopathic
phenolic acid and enriched atmospheric carbon dioxide. Water,
Air, and Soil Pollution. 106:123-136.
Blum, U., Shafer, S. R., and Lehman, M. E. 1999. Evidence
for inhibitory allelopathic interactions involving phenolic
acids in field soils: Concepts vs. an experimental model.
Critical Reviews in Plant Sciences 18:673-693.
Lehman, M. E. and Blum, U. 1999. Influence of pretreatment
stresses on inhibitory effects of ferulic acid, an allelopathic
phenolic acid. J. Chem. Ecol. 25:1517-1529.
Lehman, M. E. and Blum, U. 1999. Evaluation of ferulic acid
uptake as a measurement of allelochemical dose: Effective
concentration. J. Chem. Ecol. 25:2585-2600.
Blum, U., Staman, K. L., Flint, L. J. and Shafer, S. R.
2000. Induction and/or selection of phenolic acid-utilizing
bulk-soil and rhizosphere bacteria and their influence on
phenolic acid phytotoxicity. J. Chem. Ecol. 26:2059-2078.
Staman, K., Blum, U., Louws, F., and Robertson, D. 2001.
Can simultaneous inhibition of seedling growth and stimulation
of rhizosphere bacterial populations provide evidence for
phytotoxin transfer from plant residues in the bulk soil
to the rhizosphere of sensitive species? J. Chem. Ecol.
27:807-829.
Blum,
U. King, L. D. and Brownie, C. 2002. Effects of wheat residues
on dicotyledonous weed emergence in a simulated no-till
system. Allelopathy J. 9:159-176.
Wright, A. N., Warren, S. L., Blazich, F. A. and Blum U.
2004. Root and shoot growth periodicity of Kalmia latifolia 'Sarah' and Ilex crenata 'Compacta'. HortScience 39:243-247.
Blum, U. and Gerig, T. M. 2005. Relationships between phenolic
acid concentrations, transpiration, water utilization, leaf
area expansion, and uptake of phenolic acids: Nutrient culture
studies. J. Chem. Ecol. 31:1907-1932.
Blum, U. and Gerig, T. M. 2006. Interrelationships between
p-coumaric acid, evapotranspiration, soil water content,
and leaf expansion. J. Chem. Ecol. 32:1817-1834.
Book Chapters
Heck, W. W., Blum, U. Reinert, R. A. and Heagle, A. S. 1982.
Effects of air pollution on crop production. In: Strategies
of Plant Reproduction (BARC Symposium No. 6 -Werner J. Meudt,
Ed.) Allanheld, Osmun, and Co. Pub. Inc., London. Pages
333-350.
Heck, W. W., Blum, U., Boss, W. F., Heagle, A. S., Linthurst,
R. A. Reinert, R. A., Reynolds J. F. and Rogers, H. 1984.
Perspectives of air pollution research on plants. In:
Reviews In Environmental Toxicology I. (E. Hodgson, Ed.)
Elsevier Science Publishers, Amsterdam. Pages 173-249.
Blum, U. 1986. Plants defend themselves chemically. In:
Research for Tomorrow - 1986 Yearbook of Agriculture. (J.
J. Crowley Ed.) USDA, Beltsville. Pages 139-142.
Blum,
U. 1995. The value of model plant-microbe-soil systems for
understanding processes associated with allelopathic interactions.
In: Allelopathy: Organisms, Processes, and Applications.
(Inderjit, K.M.M. Daskshini and F. A. Einhellig Eds.) ACS
Symposium Series No. 582. American Chemical Society, Washington
DC. Pages 127-131.
Blum,
U. 1999. Designing laboratory plant debris-soil bioassays:
Some reflections. In: Principles and Practices in Plant
Ecology: Alleochemical Interactions. (Inderjit, K.M.M.
Daskshini and C. L. Foy Eds.) CRC Press, Boca Raton. Pages
17-23.
Blum,
U., Austin, M. F. and Shafer, S. R. 1999. The fates and
effects of phenolic acids in a plant-microbe-soil model
system. In Recent Advances in Allelopathy I. A Science for
the Future. (F. A. Macias, J. G. C. Galindo, J. M. G. Molinillo,
and H. Cutler Eds.) Cadiz University Press, Puerto Real.
Pages 159-166.
Blum,
U. 2001. Allelopathy. In Encyclopedia of Plant Pathology.
(O. C. Maloy and T. D. Murray, Eds.) John Wiley and Sons,
Inc., New York. Pages 33-34.
Blum, U. 2004. Fate of phenolic allelochemicals in soils:
The role of soil and rhizosphere microorganisms. In: Allelopathy:
Chemistry & Modes of Action of Allelochemicals. (F.
A. Macias, J. G. C. Galindo, J. M. G. Molinillo, and
H. Cutler Eds). CRC Press, Boca Raton. Pages 57 -76.
Blum,
U. 2006. Allelopathy: A soil system perspective. In Allelopathy.
A Physiological Process with Ecological Implications. (M.
J. Reigosa, N. Pedrol, and L. Gonzalez EDS). Springer, Dordrecht,
The Netherlands. Pages 299-340.
Blum, U. 2007. Can data derived from field and laboratory
bioassays establish the existence of allelopathic interactions
in nature? In: Allelopathy: New Concepts and Methodology.
(Y. Fujii and S. Hiradate, Eds.) Science Publishers, New
Hampshire. Pages 31-38.
Blum, U. 2011. Plant-plant allelopathic interactions. Phenolic acids, cover crops and weed emergence. Springer Science Business Media,Dordrecht
Teaching Publications
Blum, U. (with contributions by N. Allen and D. Robertson)
1998. Laboratory Manual. Plant Biology BO 295. Plant Biology,
NCSU. 58 pages
Blum, U. (with contributions by N. Allen, D. Robertson, K. Shank, K. Staman, and S. Wyatt) 1999. Laboratory Manual. Plant Biology BO 250 L. Ed. 2. Plant Biology, NCSU. 52 pages
Blum, U. (with contribution by N. Allen) 2000. Laboratory Manual. Plant Biology BO 250 L. Ed. 3. Plant Biology, NCSU. 57 pages.
Blum,
U. 2000. Lecture Course Pack. Plant Biology BO 250.
Plant Biology, NCSU. 92 pages.
Blum, U. (with contributions by N. Allen and D. Robertson)
2001. Laboratory Manual. Plant Biology BO 250 L. Ed. 4.
Plant Biology, NCSU. 60 pages.
Blum, U. 2001. Lecture Course Pack. Plant Biology BO 250.
Ed. 2. 100 pages.
Other Publications and Reports
Seneca, E. D., L. M. Stroud, U. Blum and G. R. Noggle. 1974.
An analysis of the effects of the Brunswick Nuclear Power
Plant on the productivity of Spartina alterniflora (smooth
cordgrass) in Oak Island, Dutchman Creek and Walden Creek,
Snow's Marshes, Brunswick County, NC. 1973-1974. First Annual
Report, April, 1974. pp. 1 to 68.
Seneca, E. D., L. M. Stroud, U. Blum and G. R. Noggle. 1975.
An analysis of the effects of the Brunswick Nuclear Power
Plant on the productivity of Spartina alterniflora (smooth
cordgrass) in the Dutchman Creek, Oak Island, Snow's Marsh,
and Walden Creek Marshes, Brunswick County, NC. 1974-1975.
Second Annual Report, April, 1975. pp. 1-137.
Seneca, E. D., L. M. Stroud, U. Blum and G. R. Noggle. 1976.
An analysis of the effects of the Brunswick Nuclear Power
Plant on the productivity of Spartina alterniflora (smooth
cordgrass) in the Dutchman Creek, Oak Island, Snow's Marsh,
and Walden Creek Marshes, Brunswick County, NC. 1975-1976.
Third Annual Report, September, 1976. pp. 1-335.
Seneca, E. D., L. M. Stroud and U. Blum. 1977. An analysis
of the effects of the Brunswick Nuclear Power Plant on the
productivity of Spartina alterniflora (smooth cordgrass)
in the Dutchman Creek, Oak Island, Snow's Marsh, and Walden
Creek Marshes, Brunswick County, NC. 1976-1977. Fourth Annual
Report, December, 1977. pp. 1-80.
Seneca, E. D., L. M. Stroud and U. Blum. 1979. An analysis
of the effects of the Brunswick Nuclear Power Plant on the
productivity of Spartina alterniflora (smooth cordgrass)
in the Dutchman Creek, Oak Island, Snow's Marsh, and Walden
Creek Marshes, Brunswick County, NC. 1977-1978. Fifth Annual
Report, January 1979. pp. 1-223.
Cammen, L. M., U. Blum, E. D. Seneca and L. M. Stroud. 1980.
Preliminary energy budget for a salt marsh. In the Cape
Fear Rivery Estuary, NC UNC Sea Grant College Publication
UNC-SG-WP-80-3. pp. 1-35.
Seneca, E. D., R. A. Linthurst, L. M. Stroud and U. Blum.
1980. An analysis of the effects of the Brunswick Nuclear
Power Plant on the productivity of Spartina alterniflora (smooth cordgrass) in the Dutchman Creek, Oak Island, Snow's
Marsh, and Walden Creek Marshes. Sixth and Final Report,
February 1980. pp. 1-354.
Dr. Udo Blum