Contact Information:

407 Agricultural Sciences and Industries Building University Park, PA 16802
  • Phone: 814-863-1018
  • Fax: 814-863-7043
  • E-mail: gwr@psu.edu

Appointment:

  • 75% Extension
  • 25% Research

Links:

Gregory W. Roth

Gregory W. Roth
Professor of Agronomy and State Program Leader for Renewable and Alternative Energy

Responsibilities and Interests:

In my position as the extension grain crops specialist, I develop educational programs for extension agents, agribusiness groups and producers on timely issues such as managing crops during drought stress, GMO issues, potential of specialty corn hybrids, managing for grain quality, organic grain production and producing corn for silage. I also conduct applied field research on various issues. A key research focus has been managing corn for silage production using different hybrids and management strategies and then using various models to estimate the profitability of the these practices on dairy farms. We also evaluate the yield and quality traits of transgenic corn hybrids and their adaptability to our region. We are also studying the potential of added value wheat and barley varieties to try to create more opportunities for crop producers in the state.

Education:

Professional Background:

Selected Publications:

  1. G.W. Roth, D.B. Beegle, S.M Heinbarugh, and M.E. Antle. 2006. Starter fertilizers for corn on soils testing high in phosphorous in Northeastern USA. Agron. J. (in press)
  2. M.W. Myers, W.S. Curran, M.J. Vangessel, Brad Majek, B.A. Scott, D.A. Mortensen, D.D. Calvin, H.D. Karsten, and G.W. Roth. 2005. The effect of weed density and application timing on weed control and corn grain yield. Weed Technology. 19:102-107.
  3. M.W. Myers, W.S. Curran, M.J. Vangessel, Brad Majek, D.A. Mortensen, D.D. Calvin, H.D. Karsten, and G.W. Roth. 2005. Effect of soil disturbance on annual weed emergence in the Northeastern United States. Weed Technology. 19:274-282.
  4. B.L. Dillehay, D.D. Calvin, G.W. Roth, J.A. Hyde, R.J. Kratochvil, J.M. Russo and D.G. Voight. 2005. Verification of a European Corn Borer (Lepidoptera Crambidae) loss equation in the major corn production region of the Northeastern United States. J. Econ. Entomol. 96(1): 103-112.
  5. Thomison, P.R., G. W. Roth, R. W. Elmore, and J.G. Lauer. 2004. A model for testing new seed technologies. Journal of Extension 42(4): http://www.joe.org/joe/2004august/iw5.shtml.
  6. Werner, E.L., W.S. Curran, J.K. Harper, G.W. Roth and D.P. Knievel. 2004. Velvetleaf (Abutilon theophrasti) interference and seed production in corn silage and grain. Weed Technology 18 (3): 779-783.
  7. Myers, M.W., W.S. Curran, M. J. Vangessel, D.D. Calvin, D.A. Mortensen, B.A. Majek, H.D. Karsten, and G. W. Roth. 2004. The effect of weed density and application timing on weed control and corn (Zea mays) grain yield. Weed Science 52:913-919.
  8. Dillehay, B.L, G.W. Roth, D. D. Calvin, G.L. Kuldau, J. Hyde and R. Kratochvil. 2004. Performance of Bt-corn hybrids, their near isolines and leading corn hybrids in Pennsylvania and Maryland Agron. J. 96(3):818-824
  9. Lauer, J.G., G. W. Roth and M. Bertram. 2004. Impact of defoliation on corn forage. Agron. J. 96: 1459-1463.
  10. Roth, G.W., D.B. Beegle, and M.E. Antle. 2003. Evaluation of starter fertilizers for corn on soils testing high for phosphorous. Comm. in Soil Sci. and Plant Anal. 34:1381-1392.
  11. Rotz, C.A., G.W. Roth, and W.L. Stout. 2002. Economic and environmental implications of small grain production and use on Pennsylvania dairy farms. Applied Engineering in Agriculture. Vol. 18(4): 417–428.
  12. Roth, G.W., J.K. Harper, A.A. Hower, and R.A. Kyper. 2002. Potential of Shorter Corn/Alfalfa Rotations for Dairy Farms. Journal of Sustainable Agriculture 20(2): 41-52 (principal author)
  13. Esbenshade, W.R., W.S. Curran, G.W. Roth, N.L. Hartwig, and M. D. Orzolek. 2001. Effect of row spacing and herbicides on burcucumber (Sicyos angulatus) control in herbicide resistant corn (Zea mays). Weed Technology 15 (2): 348-354.
  14. Esbenshade, W.R., W.S. Curran, G.W. Roth, N.L. Hartwig, and M. D. Orzolek. 2001. Effect of tillage, row spacing, and herbicide on the emergence and control of burcucumber (Sicyos angulatus) in soybean (Glycine max). Weed Technology 15 (2):229-235.
  15. Esbenshade, W.R., W.S. Curran, G.W. Roth, N.L. Hartwig, and M. D. Orzolek. 2001. Effect of establishment date and crop competition on burcucumber fecundity. Weed Science 49(4): 524-527.
  16. Rotz, C. A. , G. W. Roth, K.J. Soder, and R. R. Schnabel. 2001. Economic and environmental implications of soybean production and use on Pennsylvania dairy farms. Agron. J. 93:418-428.
  17. Rotz, C.A., K.J. Soder and G.W. Roth. 2001. Environmental and economic impacts of a corn and rye double crop system on a Pennsylvania dairy farm. p. 166-170. Proc. American Forage and Grassl. Conf. Springdale, Arkansas. AFGC, Georgetown, TX.
  18. Messersmith, D.T., W.S. Curran, G.W. Roth, N.L. Hartwig, M.D. Orzolek. 2000. Tillage and herbicides affect burcucumber management in corn. Agron. J. 92-181-185.
  19. Messersmith, D. T., W. S. Curran, N. L.Hartwig, M. D. Orzolek, and G. W. Roth. 1999. Evaluation of several herbicides for burcucumber (Sicyos angulatus) control in corn. Weed Technol. 13:520-524.
  20. Swartz, L., E. Chamberlain, D. Voight and G.W. Roth. 1999. Performance of Bt Corn hybrids in Pennsylvania and New Jersey. New Jersey Grain and Forage Journal 6:61-64
  21. Shoener, A., and G. W. Roth. 1999. Corn yield response to plant population in a high yield environment. New Jersey Grain and Forage Journal 6:12-15.
  22. Roth, G.W. and J.G. Lauer. 1997. Agronomist's perspective of corn hybrids for silage. p. 15-24. In Silage:field to feedbunk. Proc. NRAES North American Conference, Hershey, PA, Feb. 11-13, 1997, NRAES, Ithaca, NY.
  23. Roth, G.W. and J.O. Yocum. 1997. Use of hybrid growing degree day ratings for corn in the Northeast U.S. Journal of Prod. Ag. 10:283-288.
  24. Allen, M., S. Ford, J. Harrison, C. Hunt, J. Lauer, R. Muck, G. Roth, S. Soderlund, and D. Undersander. 1995. Corn silage production, management, and feeding. NCR 574. ASA, Madison, WI. 42 pp.
  25. Roth, G. W. and J. K. Harper. 1995. Forage Sorghum. Agronomy Facts 48. Penn State Cooperative Extension, Univ. Park, Pa.
  26. Nandula,V., W. C. Curran and G. W. Roth. 1995. Effectiveness of nicosulfuron and primisulfuron on wirestem muhly (Muhlenbergia frondosa) control in no-till corn (Zea mays). Weed Tech. 9:331-338.
  27. Nandula, V., W. C. Curran , G. W. Roth and N.L Hartwig. 1995. Effectiveness of adjuvants with nicosulfuron and primisulfuron for wirestem muhly (Muhlenbergia frondosa) control in no-till corn (Zea mays). Weed Tech. 9:525-530.
  28. Roth G. W, S. Fathi, R. H. Fox, J. R. Rosenberger and W. P. Piekielek. 1995. Effect of harvest method and feed value on the economic optimum nitrogen rate for corn. Commun. Soil Sci. Plant Anal. 26(7&8):1009-1021. Abstract.
  29. Roth, G. W., D. D. Calvin and S. M. Lueloff. 1995. Tillage, nitrogen timing and planting date effects on western corn rootworm injury to corn. Agron J. 87:189-193. Abstract.
  30. Roth, G.W. 1994. Hybrid quality and yield differences for corn silage in Pennsylvania. Journal of Production Agriculture 7:50-54. Abstract.
  31. Hartzler, R.W. and G.W. Roth. 1993 Effect of prior year's weed control on herbicide effectiveness in corn (Zea mays). Weed Technology 7:611-614.
  32. Ganoe, K.H. and G.W. Roth. 1992. Kernel milk line as an indicator of harvest timing for whole plant corn. Journal of Production Agriculture 5:519-523.
  33. Roth, G.W., D.B. Beegle and P.J. Bohn. 1992. Field evaluation of a pre-sidedress soil nitrate test and quicktest for corn in Pennsylvania. Journal of Production Agriculture 5:476-481. Abstract.
  34. Roth, G.W., D.B. Beegle, R.H. Fox, J.D. Toth, and W.P. Piekielek. 1991. Evaluation of a quicktest kit to determine soil nitrate. Commun. Soil Sci. Plant Anal. 22(3&4):191-200.
  35. Roth, G.W. and R.H. Fox. 1990. Soil nitrate accumulations following corn fertilized at various N rates in Pennsylvania. J. Env. Qual. 19:243-248.