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Sheridan Research and Extension Center|UW Research and Extension Centers

Contact Us

ShREC
3401 Coffeen Ave.
Sheridan, WY 82801
Phone: (307) 673-2856
Fax: (307) 673-4384
Email: shrec@uwyo.edu

Valtcho Jeliazkov (Zheljazkov), Ph.D.

Valtcho Jeliazkov

Associate Professor, Department of Plant Sciences
Phone: 307-673-2647
Fax: 307-673-4384
E-mail: vjeliazk@uwyo.edu

Education
2001: Ph.D. Dept. of Plant and Soil Sciences, University of Massachusetts
1988: Ph.D. in Agronomy, Higher Institute of Agriculture, Plovdiv, Bulgaria
1983: M.Sc. in Agronomy, Higher Institute of Agriculture, Plovdiv, Bulgaria

Teaching
AECL 4190 Herbs, Spices & Medicinal Plants
PLNT 5190 Herbs, Spices & Medicinal Plants
AECL 4120 Organic Food Production
PLNT 5120 Organic Food Production

Research and Teaching Interests
  • Specialty crops, medicinal and aromatic plants, plant secondary metabolites
  • Oilseeds, biofuel crops, and forages
  • Reclamation, remediation, and native plants
  • Various aspects of soil/plant relationships and nutrient management of horticultural and agronomic crops
  • Development of environmentally benign cropping systems, improving economic and environmental sustainability of crop production
  • Evaluation of ‘waste materials’ as soil amendments, benefits and potential environmental hazards
  • Electron microscopy and X-ray microanalyses.

Society Membership
American Society of Horticultural Science
American Society of Agronomy
Crop Science Society of America
Canadian Society of Agronomy
American Council for Medicinally Active Plants

Refereed Journal Papers in the last 10 years

2014

Cantrell C.L., Zheljazkov, V.D., Carvalho, C.R., Astatkie, T., Jeliazkova, E.A., Rosa, L.H. (2014) Dual Extraction of Essential Oil and Podophyllotoxin from Creeping Juniper (Juniperus horizontalis). PLoS ONE 9(9): e106057. doi:10.1371/journal.pone.0106057

Moser, B.R., V.D. Zheljazkov, E.L. Bakota, R.L. Evangelista, A. Gawde, C.L. Cantrell, J.K. Winkler-Moser, A.N. Hristov, T. Astatkie, and E. Jeliazkova. 2014. Method for obtaining three products with different properties from fennel (Foeniculum vulgare) seed. Industrial Crops and Products. 60:335–342.

Zheljazkov, V.D., T. Astatkie, and V. Schlegel. 2014. Hydrodistillation Extraction Time Effect on Essential Oil Yield, Composition, and Bioactivity of Coriander Oil. Journal of Oleo Science. 60, 335-342.

Zheljazkov, V.D., T. Astatkie, S. Shiwakoti, S. Poudyal, T. Horgan, N. Kovatcheva, and A. Dobreva. 2014. Essential Oil Yield and Composition of Garden Sage as a Function of Different Steam Distillation Times.  HortScience. 49:785-790.​

Gawde, A., C.L. Cantrell, V.D. Zheljazkov, T. Astatkie, and V. Schlegel. 2014. Steam distillation extraction kinetics regression models to predict essential oil yield, composition, and bioactivity of chamomile oil. Industrial Crops and Products 58:61–67. http://dx.doi.org/10.1016/j.indcrop.2014.04.001

Zheljazkov, V.D., T. Astatkie, and E.A. Jeliazkova. 2014. Drying and Shade Effects on Spearmint Oil Yields and Composition. HortScience. 49(3):306–310.

2013

Zheljazkov, V.D., T. Astatkie, Barry O’Brocki, and E. Jeliazkova. 2013. Essential Oil Composition and Yield of Anise from Different Distillation Times. HortScience 48(11):1393-1396.

Zheljazkov, V.D., C.L. Cantrell, T. Astatkie, V. Schlegel, E. Jeliazkova and D. Lowe. 2013. Effect of Coal-Bed Methane Water on Spearmint and Peppermint. Journal of Environmental Quality. 42(6):1815-1821. doi:10.2134/jeq2013.05.0211.

Zheljazkov, V.D., T. Astatkie, T. Horgan, V. Schlegel, and X. Simonnet. 2013. Distillation Time Effect on Essential Oil Yield, Composition, and Antioxidant Capacity of Sweet Sagewort (Artemisia annua L.) Oil.  HortScience 48(10):1288-1292.

Zheljazkov, V.D.,  T. Horgan,  T. Astatkie, and V. Schlegel. 2013. Distillation Time Modifies Essential Oil Yield, Composition, and Antioxidant Capacity of Fennel (Foeniculum vulgare Mill). Journal of Oleo Science. 62(9):665-672. http://dx.doi.org/10.5650/jos.62.665

Zheljazkov, V.D., T. Astatkie, and E. Jeliazkova. 2013. Year-round Variations in Essential Oil Content and Composition of Male and Female Juniper. HortScience. 48(7):883–886. 2013.

Zheljazkov, V.D., B. Vick, W.M. Ebelhar, N. Buehring, and T. Astatkie. 2013. Effect of N on Yield and Chemical Profile of Winter Canola in Mississippi. Journal of Oleo Sciece. 62(7):453-458. http://dx.doi.org/10.5650/jos.62.453

Zheljazkov, V.D., C.L. Cantrell, T. Astatkie, and E. Jeliazkova. 2013. Mentha canadensis L., a subtropical plant, can withstand first few fall frosts when grown in northern climate. Industrial Crops and Products. 49:521-525. http://dx.doi.org/10.1016/j.indcrop.2013.05.034

Zheljazkov, V.D., T. Astatkie, and E. Jeliazkova. 2013. Effect of foliar application of methyl jasmonate and extracts of juniper and sagebrush on essential oil yield and composition of 'Native' spearmint. HortScience. 48(4): 462-465.

Zheljazkov, V.D., C.L. Cantrell, T. Astatkie, and E. Jeliazkova. 2013. Distillation Time Effect on Lavender Essential Oil Yield and Composition. Journal of Oleo Science. 62(4):195-199.

Zheljazkov, V.D., C.L. Cantrell, M.A. Donega, and T. Astatkie. 2013. Bioprospecting for podophyllotoxin in the Big Horn Mountains, Wyoming. Industrial Crops and Products, 43:787-790.

2012

Zheljazkov, V.D., C.L. Cantrell, M.A. Donega, T. Astatkie, and B. Heidel. 2012. Podophyllotoxin Concentration in Junipers in the Big Horn Mountains in Wyoming. HortScience 47(12):1696-1697.

Zheljazkov, V.D., T. Astatkie, E. Jeliazkova, A.O. Tatman, and V. Schlegel. 2012. Distillation time alters essential oil yield, composition and antioxidant activity of female Juniperus scopulorum trees. Journal of Essential Oil Research. 25(1):62-69.

Zheljazkov, V.D., C.L. Cantrell, T. Astatkie, and E. Jeliazkova. 2012. Fall frosts effects on the essential oil of "Native" spearmint in Wyoming. HortScience 47(11):1603-16060

Zheljazkov, V.D., B.A. Vick, B.S. Baldwin, N. Buehring, T. Astatkie, and B. Johnson. 2012. Effect of Plant Date, Nitrogen Rate, and Hybrid on Sunflower. Journal of Plant Nutrition, 35(14):2198-2210.

Zheljazkov, V.D., T. Astatkie, E.A. Jeliazkova, and V. Schlegel. 2012. Distillation time alters essential oil yield, composition, and antioxidant activity of male Juniperus scopulorum trees. Journal of Oleo Science. 61(10):537-546.

Munroe, M., V. Zheljazkov, T. Astatkie, and G. Stratton. 2012. Comparison of lead extraction and detection procedures for six Canadian soils. Communications in Soil Science and Plant Analysis. 43(17): 2303-2313

Cantrell, C.L., V.D. Zheljazkov, W.A. Osbrink, A. Castro, V. Maddox, L.E. Craker, T. Astatkie. 2013. Podophyllotoxin and essential oil profile of Juniperus and related species. Industrial Crops and Products. 43:668-676.

Tekippe, J.A., A.N. Hristov, K.S. Heyler, V.D. Zheljazkov, J.F.S. Ferreira, C.L. Cantrell, G.A. Varga. 2012. Effects of plants and essential oils on ruminal in vitro batch culture methane production and fermentation. Can. J. Anim. Sci. 92(3):395-408

Zheljazkov, V.D., T. Astatkie, and V. Schlegel. 2012. Distillation time changes oregano essential oil yields and composition but not the antioxidant or antimicrobial activities. HortScience 47(6):777-784

Zheljazkov, V.D., T. Astatkie, and V. Schlegel. 2012. Effects of distillation time on the Pinus ponderosa essential oil Yield, composition, and antioxidant activity. HortScience 47(6):785-789

Ferreira, J.F.S., V.D. Zheljazkov, and J.M. Gonzales. 2013. Artemisinin concentration and antioxidant capacity of Artemisia annua distillation byproduct. Industrial Crops and Products. 41:294-298

Cannon, J.B., C.L. Cantrella, T. Astatkie, and V.D. Zheljazkov. 2013. Modification of yield and composition of essential oils by distillation time. Industrial Crops and Products. 41:214- 220.

Zheljazkov, V.D., and T. Astatkie. 2012. Effect of distillation time on Mentha canadensis essential oil yield and composition. HortScience. 47(5):643-647.

2011

Zheljazkov, V.D. and T. Astatkie. 2011.  Effect of plant species and benomyl on lead concentration and removal from lead-enriched soil. HortScience. 46(12):1604-1607.

Zheljazkov, V.D. and T. Astatkie. 2012. Distillation waste water can modify peppermint (Mentha ×piperita L.) oil composition. Industrial Crops and Products. 36 (2012) 420- 426.

Zheljazkov, V.D., T. Horgan, T. Astatkie, D. Fratesi, and C.C. Mischke. 2011. Study on shrimp waste water and vermicompost as a nutrient source for bell peppers. HortScience. 46:1493-1496.

Zheljazkov, V.D., T. Astatkie, and A.N. Hristov. 2012.  Lavender and hyssop productivity, oil content, and bioactivity as a function of harvest time and drying. Industrial Crops and Products. 36(1):222-228.

Zheljazkov, V.D., B. Vick, M.W. Ebelhar, N. Buehring, and T. Astatkie. 2012. Nitrogen applications modify seed and oil yields and fatty acid composition of winter mustard. Industrial Crops and Products. 36:28-32.

Tekippe, J.A., A.N. Hristov, K.S. Heyler, T.W. Cassidy, V.D. Zheljazkov, J.F.S. Ferreira, S.K. Karnati, and G.A. Varga. 2011. Rumen fermentation and production effects of Origanum vulgare L. in lactating dairy cows. Journal of Dairy Science. 94:5065–5079.

Dobreva, A., N. Kovatcheva, T. Astatkie, and V.D. Zheljazkov. 2011. Improvement of essential oil yield of oil-bearing rose (Rosa damascena Mill.) due to surfactant and maceration.  Industrial Crops and Products. 34(3):1649-1651.

Kovatcheva, N., V.D. Zheljazkov, and T. Astatkie. 2011. Productivty, oil content, composition, and bioactivity of oil-bearing rose accessions. HortScience. 46(5):710-714.

Zheljazkov, V.D., C.L. Cantrell, T. Astatkie, and J.B. Cannon. 2011. Lemongrass productivity, oil content, and composition as a function of N, S, and harvest time. Agronomy Journal. 103:805-812.

Zheljazkov, V.D., and T. Astatkie. 2011. Effect of Residual Distillation Water of 15 Plants and Three Plant Hormones on Scotch Spearmint (Mentha × gracilis Sole). Industrial Crops and Products. 33(3):704-709

Zheljazkov, V.D., C.L. Cantrell, and T. Astatkie. 2011. Variation in Podophyllotoxin Concentration in Leaves and Rhizomes of American mayapple (Podophyllum peltatum L.). Industrial Crops and Products. 33(3): 633-637

Zheljazkov, V.D., and T. Astatkie. 2011. Effect of Distillation Waste Water and Plant Hormones on Spearmint Growth and Composition. J. Sci. Food Agric. Journal of the Science of Food and Agriculture.91(6):1135-1141

Zheljazkov,V.D., Brady A. Vickb, Brian S. Baldwin, Normie Buehring, Christine Coker, Tess Astatkie, and Billy Johnson. 2011. Oil Productivity and Composition of Sunflower as a Function of Hybrid and Planting Date. Industrial Crops and Products. 33:537-543.

2010

Zheljazkov, V.D., C.L. Cantrell, and T. Astatkie. 2010. Yield, content, and composition of peppermint and spearmints as a function of harvesting time and drying. Journal of Agricultural and Food Chemistry. 58:11400–11407.

Zheljazkov, V.D., C.L. Cantrell, and T. Astatkie. 2010. Yield and composition of Japanese cornmint fresh and dry material harvested successively. Agronomy Journal. 102(6):1652-1656.

Zheljazkov, V.D., T. Astatkie, T. Horgan, and S. Marie Rogers. 2010. Effect of plant hormones and distillation water on mints. HortScience. 45(9):1338-1340.

Zheljazkov, V.D., C.L. Cantrell, and T. Astatkie. 2010. Study on Japanese cornmint in Mississippi. Agronomy Journal. 102(2):696-702.

Zheljazkov, V.D., C.L. Cantrell, T. Astatkie, and M.W. Ebelhar. 2010. Productivity, Oil Content and Composition of Two Spearmint Species in Mississippi. Agronomy Journal. 102(1):129-133.

Zheljazkov, V.D., C.L. Cantrell, T. Astatkie, and M.W. Ebelhar. 2010. Peppermint Productivity and Oil Composition as a Function of Nitrogen, Growth Stage, and Harvest Time. Agronomy Journal. 102(1):124-128.

2009

LeRiche, E.L., G. Wang-Pruski, and V.D. Zheljazkov. 2009. Distribution of elements in potatoes (Solanum tuberosum L.) and their relationship to after-cooking darkening. HortScience. 44(7):1866-1873.

Zheljazkov, V.D., V.K. Cerven, C.L. Cantrell, and M.W. Ebelhar. 2009. Effect of N, location, and harvesting stage on peppermint productivity, oil content, and oil composition. HortScience. 44:1267–1270.

Gawde, A.J., C.L. Cantrell, and V.D. Zheljazkov. 2009. Dual extraction of essential oil and podophyllotoxin from Juniperus virginiana. Industrial Crops and Products. 30:276-280.

Zheljazkov, V.D., B.A. Vick, B. Baldwin, N. Buehring, and T. Astatkie. 2009. Oil Content and Saturated Fatty Acids in Sunflower (Helianthus annuus L.) as a Function of Planting Date, N Rate and Hybrid. Agronomy Journal. 101(4): 1003-1011.

Gawde, A.J. V.D. Zheljazkov, V. Maddox, and C.L. Cantrell. 2009. Bioprospection of Eastern red cedar from nine physiographic regions in Mississippi. Industrial Crops and Products. 30:59-64.

Zheljazkov, V.D., G.W. Stratton, J. Pincock, S. Butler, E.A. Jeliazkova, N.K. Nedkov, and P.D. Gerard. 2009. Wool waste as organic source for container grown plants. Waste Management. 29:2160-2164.

Zheljazkov, V.D., B. Avula, A.M. Jones, V. Maddox, and D.E. Rowe. 2009. Lignan and nutrient concentrations in American Mayapple (Podophyllum peltatum L.) in the Eastern United States. HortScience. 44(2):349-353.

2008

Zheljazkov, V.D., G.W. Stratton, and T. Sturz. 2008. Uncomposted wool and hair-wastes as soil amendments for high-value crops. Agronomy Journal. 100:1605–1614.

Zheljazkov, V.D., and P. McNeil. 2008. Comparison of five digestion procedures for recovery of nutrients and trace elements in plant tissue. Journal of Plant Nutrition. 31(11):1937-1946.

Zheljazkov, V.D., E. Jeliazkova, N. Kovatcheva, and A. Dzhurmanski. 2008. Metal uptake by medicinal plant species grown in soils contaminated by a smelter. Environmental and Experimental Botany. 64:207-216.

Zheljazkov, V.D., J.L. Silva, M. Patel, J. Stojanovic, Y. Lu, T. Kim, and T. Horgan. 2008. Human Hair as Nutrient Source for Horticultural Crops. HortTechnology. 18(4):592-596.

Wilson, J., V.D. Zheljazkov, B. Rathgeber, D. Burton, and C.D. Caldwell. 2008. Reduction of phosphorus availability in poultry and dairy manure using mineral amendments. Soil Science and Plant Nutrition. 54:600-605.

Zhejazkov, V.D., C.L. Cantrell, M.W. Ebelhar, D. Rowe, and C. Coker. 2008. Productivity, oil content, and oil composition of sweet basil as a function of nitrogen and sulfur fertilization. HortScience. 43(5):1415-1422.

Zheljazkov, V.D., C.L. Cantrell, W.B. Evans, M.W. Ebelhar, and C. Coker. 2008. Yield and composition of Ocimum basilicum L. and Ocimum sanctum L. grown at four locations. HortScience. 43(3):737-741.

Zheljazkov, V.D., K.M. Bowes, C.D. Caldwell, J.A. Pincock, J.C. Roberts, and L. Mapplebeck. 2008. Cultivar and sowing date effects on seed yield and oil composition of coriander in Atlantic Canada. Industrial Crops and Products. 28:88-94.

Urbaniak, S.D., C.D. Caldwell, V.D. Zheljazkov, R. Lada and L. Luan. 2008. The effect of seeding rate, seeding date and seeder type on the performance of Camelina sativa L. in the Maritime Provinces of Canada. Canadian Journal of Plant Science. 88:501-508.

Zheljazkov, V.D., B.A. Vick, M.W. Ebelhar, N. Buehring, B. Baldwin, T. Astatkie, and J.F. Miller. 2008. Yield, oil content, and composition of sunflower (Helianthus annuus L.) grown at multiple locations in Mississippi. Agronomy Journal. 100:635-642.

Zheljazkov, V.D., L.E. Craker, B. Xing, N.E. Nielsen, and A. Wilcox. 2008. Aromatic plant production on metal contaminated soils. Science of the Total Environment. 395:51-62.

Zheljazkov, V.D., C.L. Cantrell, B. Tekwani, S. Khan. 2008. Content, composition, and bioactivity of the essential oil of three basil genotypes as a function of harvesting. Journal of Agricultural and Food Chemistry. 56(2):380-385.

Zheljazkov, V.D., A. Callahan, and C.L. Cantrell. 2008. Yield and oil composition of thirty-eight basil (Ocimum basilicum L.) accessions grown in Mississippi. Journal of Agricultural and Food Chemistry. 56(1):241-245.

Urbaniak, S.D., C.D. Caldwell1, V.D. Zheljazkov, R. Lada and L. Luan. 2008. The effect of cultivar and applied nitrogen on the performance of Camelina sativa L. in the Maritime Provinces of Canada. Canadian Journal of Plant Science. 2008. 88:111-119.

2007

Parsons, K.J., V.D. Zheljazkov, J. MacLeod, and C.D. Caldwell. 2007. Soil and tissue P, K, Ca and S as affected by dairy manure application in a no-till corn, wheat and soybean rotation. Agronomy Journal. 99:1306-1316.

Zheljazkov, V.D., C.L. Cantrell, M.W. Ebelhar, C. Coker, and W.B. Evans. 2007. Quality assessment and yield of baikal skullcap (Scutellaria baicalensis) grown at multiple locations across Mississippi. HortScience. 42(5):1183-1187.

Zheljazkov, V.D., K. Patterson, K.J. Parsons, and G. Sampson. 2007. Tolerance of bare-root ornamental perennials to selected herbicides. Canadian Journal of Plant Science. 439–442.

2006

LeRiche, E.L., G. Wang-Pruski, and V.D. Zheljazkov. 2006. Mineral concentration and distribution in tubers of fertilized and unfertilized potato cultivars Shepody and Russet Burbank as determined by VP-SEM/EDS. Canadian Journal of Plant Science. 86:1349-1353.

Zheljazkov, V.D., I. Zhalnov, and N. Nedkov. 2006. Herbicides for weed control in blessed thistle (Silybum marianum). Weed Technology. 20(4):1030-1034.

Zheljazkov, V.D., T. Astatkie, C.D. Caldwell, J. MacLeod, and M. Grimmett. 2006. Compost, manure, and gypsum application to timothy/red clover forage. Journal of Environmental Quality. 35:2410-2418.

Zheljazkov, V.D., L.E. Craker, and B. Xing. 2006. Effects of Cd, Pb, and Cu on growth and essential oil contents in dill, peppermint, and basil. Environmental and Experimental Botany. 58(1-3):9-16.

2005

Zheljazkov, V.D. 2005. Assessment of wool-waste and hair-waste as soil amendment and nutrient source. Journal of Environmental Quality. 34:2310-2317.

2004

Bowes, K. and V.Zheljazkov, 2004. Essential oil yields and quality of fennel grown in Nova Scotia. HortScience. 39(7):1640-1643.

Bowes, K. V. Zheljazkov, C. Cadwell, J. Pinckock, and J. Roberts. 2004. Influence of seeding date and harvest stage on yields and essential oil composition of three cultivars of dill (Anethum graveolens L.) Grown in Nova Scotia. Canadian Journal of Plant Science. 84:1155-1160.

Bowes, K. and V. Zheljazkov. 2004. Ocimum sanctum L. and Ocimum basilicum L. Grown in Nova Scotia, Canada show potential as essential oil crops. Journal of the American Society for Horticultural Science. 129(6):789-794.

Zheljazkov, V.D. and P.R. Warman. 2004. Phytoavailability and Fractionation of Cu, Mn, and Zn in soil following application of two composts to four crops. Environmental Pollution. 131(2):187-195.

Zheljazkov, V.D. and P.R. Warman. 2004. Application of high Cu compost to dill and peppermint. Journal of Agricultural and Food Chemistry. 52:2615-2622.

Zheljazkov, V.D. and P.R. Warman. 2004. Source Separated Municipal Solid Waste Compost Application to Swiss Chard and Basil. Journal of Environmental Quality. 33:542-552.

2003

Zheljazkov, V.D. and P.R. Warman. 2003. Application of High Cu Compost to Swiss Chard and Basil. Science of the Total Environment. 302:13-26.

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