Daniel Hoover Willits

Professor and Director of Graduate Programs

EDUCATION:

• Ph.D.,University of Kentucky,1974, Agricultural Engineering
• MSE, University of Florida, 1967, Agricultural Engineering
• BSME, University of Florida, 1966, Mechanical Engineering

PROFESSIONAL EXPERIENCE:

• 2010 - , Assistant Dean for Academic Affairs, The Graduate School, NCSU
• 2008- 2010, Interim Assist Dean for Academic Affairs, The Graduate School, NCSU
• 2000- , Director of Graduate Programs, Bio. and Agri. Eng. Dept., NCSU.
• 1986- , Professor, Bio. and Agri. Eng. Dept., NCSU.
• 1979-86, Associate Professor, Bio. and Agri. Eng. Dept., NCSU.
• 1974-79, Assistant Professor, Bio. and Agri. Eng. Dept., NCSU.
• 1972-74, Graduate Fellow (NDEA), University of Kentucky.
• 1967-72, Group Mech Design Eng, USAF Crypt. Depot, Kelly AFB, TX.
• 1967-67, Graduate Assistant, University of Florida.

RESEARCH AREAS:

• Environmental control of greenhouses
• Plant/environment interactions
• Computer modelling of plant environments

PROFESSIONAL SOCIETIES AND OFFICES

American Society of Agricultural Engineers:

• PM-59, Nursery and Greenhouse Mech Committee: member and past chair
• SE-303, Plant Struc and Env Committee: member and past chair
• SE-05, Publication Review: former assoc editor
• PM-07, Power and Machinery Programs: past member and prgm coord

MAJOR COMMITTEES:

• University:
  • Graduate Administrative Board (2005 - )
  • Provost's Committee on Distance Learning (1999-2001)
  • Academic Policy Committee (Faculty Senate: 1998-2000)
  • Provost's Committee for Student Computing: (1993-94), chair (1994-95)
  • University Dining Committee: (1987-90)
  • University Coliseum Committee: (1981-85)
• College:
  • CALS Graduate Studies Committee (member, 2004-2005; chair, 2005 - )
  • COE Graduate Studies Committee: (2000 - )
  • CALS Distance Learning Committee (1999- )
  • CALS Academic Computer Advisory Committee: (1991- 1999), chair (1993-94)
  • CALS Strategic Planning Committee, Subgroup 9: (1993-94)
  • COE Graduate Studies Committee: (1982-86)
• Department:
  • Executive Committee (2000 - )
  • Graduate Studies Committee chair (1999 - )
  • Distance Learning Committee chair (1999 - )
  • Computer Advisory Committee: (1983- ), chair (1983-86; 1997- 00)
  • Graduate Studies Committee: (1976-93; 1999- ; chair 2000 - )
  • Curriculum Committee: (1989-90)
  • SPA Evaluation Committee: (1986)

GRANTS AND CONTRACTS:

• Willits, D.H., M. Teitel, A. Swartz, S. Shabtai, M. Peet, J. Tanny, Eli Matan. 2008. Stress and fault detection in greenhouse production by direct measurement of crop status. Proposal submitted to BARD. $375,580. Not funded.
• Willits, D.H. 2008. Enhancing E-learning Programs in BAE. UNC General Administration. $30,000.
• Shah, S., D. Willits, P. Westerman, L. Wang. 2008. Design, Evaluate, and Model a 'Second Generation' Regenerating Scrubber for Reducing Ammonia Emissions from Animal Houses. Submitted to NSF. $285,406. Declined
• Willits, D. H. 2007. Full Scale Testing of Ludvig Svensson Shade Cloths. Memorandum of Agreement with Ludvig Svensson, Inc., $8,919.
• Willits, D. H. 2006a. Radiation Characteristics of Reflective Shade Cloths. Memorandum of Agreement with Ludvig Svensson, Inc., $4,600.
• Losordo, T. M. and D. H. Willits. 2006b. A Thermal Evaluation of Super-intensive Shrimp Production Systems. South Carolina Department of Natural Resources. $10,008.
• Losordo, T. M. and D. H. Willits. 2006c. A Thermal Evaluation of Super-intensive Shrimp Production System: Year II, Model Validation and Design Assistance. South Carolina Department of Natural Resources. $20,730.
• Grabow, G.L., Parsons J.E., Huffman, R.L. and Willits, D.H. Development of On-Line Modules for Use in Environmental Engineering Programs in BAE. Distance Education and Learning Technology Applications Division, NCSU. $52,585 for two years.
• Willits, D.H., M. Teitel, T. Josef, M.M. Peet, S. Cohen and E. Matan. 2001-03. Comparing the performance of naturally ventilated and fan-ventilated greenhouses. BARD, Israel. $168,000 (US) and $156,000 (IS).
• Roberson, G.T. and D.H. Willits. 2001. Converting an agricultural safety and health course to distance education format. Distance Education and Learning Technology Applications Division, NCSU. $2,750.
• Willits, D.H. 2001. Planning a distance education program in environmental engineering. Distance Education and Learning Technology Applications Division, NCSU. $10,000.
• W.F. Hunt, J.J. Classen and D.H. Willits. 2001. Converting two environmental engineering courses to distance education format. Distance Education and Learning Technology Applications Division, NCSU. $17,500.
• Cheng, J., D.H. Willits and M.M. Peet. 2000-02. Ambient temperature anaerobic digester and greenhouse for swine waste treatment and bioresource recovery at Barham Farm. NCSU Animal and Poultry Waste Management Center. $196,896 for evaluation phase and $436,000 for implementation phase (directly to Julian Barham).
• Willits, D.H., M.M. Peet and J. Cheng. 2000. Estimating photosynthesis from fluorescence yield. College of Agriculture and Life Sciences Equipment Fund. $6,600.
• Willits, D. H., M. M. Peet and J. Cheng. 2000. Using a greenhouse tomato crop to recover bioresources from swine waste: system improvements. North Carolina Pork Council. $27,325
• Willits, D. H. 1999. Integrating swine waste management technology with greenhouse tomato production: electricity, waste heat and CO₂ utilization. North Carolina Agricultural Foundation. $41,725 for MS assistantship.
• Willits, D.H., M.M. Peet, J. Cheng, M. Sobsey, R.W. Bottcher, R.E. Sheffield, K. Keener, E. Estes, and K.D. Zering. 1999. Using a greenhouse tomato crop to recover bioresources from swine waste: a systems approach. North Carolina Agricultural Research Service, $246,000.
• Willits, D.H. 1998. The use of heat pumps in greenhouse operations. Fred C. Gloeckner Foundation, Inc., $20,000.
• Willits, D.H. 1998. Chlorophyll fluorescence as an objective means of determining heat stress in chrysanthemum. Fred C. Gloeckner Foundation, Inc. $6,400.
• Seginer, I., D.H. Willits, M. Raviv and M. M. Peet. 1996. Transpirational cooling of a greenhouse crop. BARD. $338,149.
• Fred C. Gloeckner Foundation, Inc. 1994. Shade cloth misting as a means of improving greenhouse cooling. $5,214. Principal Investigator
• Fred C. Gloeckner Foundation, Inc. 1993. Night temperature reduction as a means of improving floral initiation in poinsettia and chrysanthemum. $5,892. Principal Investigator
• NCSU Faculty Development Program. 1983. Use of Photosynthetic Response Surfaces to Develop Predictive Models for Greenhouse CO₂ Control. Proposal Development Grant. $500. Co-investigator.
• DOE/SEA Program Solar Energy Systems for Agriculture. 1981-84. CO₂ enrichment in solar energy collection/storage systems for greenhouses. $77,000. Principal Investigator.
• DOE/SEA Cooperative Agreement. 1978-80. Low-grade thermal energy storage systems for greenhouses. Three consecutive one-year grants totalling $66,531. Principal Investigator.

AWARDS AND HONORS:

• Keynote Speaker, Int Symp on Greenhouse Cooling: Methods, Technologies and Plant Response, 24-27 April, 2006, Almeria, Spain.
• Keynote Speaker, Int. Conf. on Greenhouse Tech. towards the 3rd Mill., 6-8 Sept 1999, Haifa, Israel.
• ASAE Paper Award, 1987.
• ASAE Paper Award, Honorable Mention, 1987.
• Sigma Xi, 1974.
• Tau Beta Pi, 1974.
• Gamma Sigma Delta, 1973.
• NDEA Fellow, 1972-74.
• Air Force Commendation Medal, USAF, 1971.
• Phi Kappa Phi, 1967.
• Distinguished Military Graduate, ROTC, 1966.

Refereed Articles

1. Yao, H., S.B. Shah, D.H. Willits, P.W. Westerman, L. Wang Li, T.K. 2011. Marshall. Ammonia emissions from broiler cake stockpiled in a naturally ventilated shed. Trans of the ASABE, 54(5):1893-1904.
2. *Li, S.H., D.H. Willits, C.L. Browdy, M.B. Timmons, T.M. Losordo. 2009. Thermal modeling of greenhouse aquaculture raceway systems. Aquacultural Engineering (41) 1-13.
3. *Li, S. and D. H. Willits. 2008. An Experimental Evaluation of Thermal Stratification in a Fan-Ventilated Greenhouse. Trans of the ASABE. 51(4): 1443-1448.
4. *Li, S. and D. H. Willits. 2008. Modeling Thermal Stratification in Fan-Ventilated Greenhouses. Trans of the ASABE. 51(5): 1735-1746
5. *Li, S. and D. H. Willits. 2008. Comparing low-pressure and high-pressure fogging systems in naturally ventilated greenhouses. Biosystems Engineering 101(1):69-77.
6. Willits, D.H. 2006. Fan Ventilated Greenhouse Cooling: Some Considerations for Design. Acta Hort. 719: 83-96.
7. Willits, D.H., S. Li and C.A. Yunker. 2006. The Cooling Performance of Naturally Ventilated Greenhouses in the Southeastern US. Acta Hort. 719:73-80.
8. *Li, S., D. Willits and C.A. Yunker. 2006. Experimental Study of a High Pressure Fogging System in Naturally Ventilated Greenhouses. Acta Hort. 393-400.
9. Willits, D.H. and Y. R. Gurjer. 2004. Heat pumps for the heating and night-cooling of greenhouse crops: a simulation study. Trans of the ASAE. Vol. 47(2): 575-584
10. Willits, D.H. 2003. The Effect of Cloth Temperature on the Cooling Efficiency of Shade Cloths in Greenhouses. Trans of the ASAE 46(4): 1215-1221
11. Willits, D.H. 2003. Cooling fan-ventilated greenhouses: a modeling study. Biosystems Engineering 84(3): 315-329.
12. Willits, D.H. 2003. The Effect of Cloth Temperature on the Cooling Efficiency of Shade Cloths in Greenhouses. Transactions of the ASAE, 46(4): 1215–1221
13. Willits, D.H. and Peet, M.M. 2001. Measurement of chlorophyll fluoresence as a heat stress indicator in tomato: Laboratory and greenhouse comparisons. J. Amer. Soc. Hort. Sci. 126(2):188-194.
14. Willits, D. 2001. The effect of cloth characteristics on the cooling performance of external shade cloths for greenhouses. J. Agric. Eng. Res. 79(3):331-340
15. Willits, D.H. and Peet, M.M. 2000. Intermittent application of water to an externally mounted greenhouse shade cloth to modify cooling performance. Transactions of the ASAE 43(5):1247-1252.
16. Willits, D.H. and D.A. Bailey. 2000. The effect of night temperature on chrysanthemum flowering: heat tolerant vs. heat sensitive cultivars. Scientia Hort. 83(3):325-330.
17. Willits, D. H. and M. M. Peet. 2000. Intermittent Application of Water to an Externally Mounted, Greenhouse Shade Cloth to Modify Cooling Performance. Trans of the ASAE 43(5):1247-1252.
18. Willits, D.H. 2000. Constraints and limitations in greenhouse cooling: Challenges for the next decade. Acta Hort. 534:57-66.
19. Willits, D.H. and Peet, M.M. 1999. Using chlorophyll fluorescence to model leaf photosynthesis in greenhouse pepper and tomato. Acta Hort. 507, pp 311-315.
20. Willits, D.H. and M.M. Peet. 1998. The effect of night temperature on greenhouse grown tomato yields in warm climates. Agr. and For. Meteor. 92:191-202.
21. *Jacobson, B.M., D.H. Willits and P.V. Nelson. 1998. Dynamic internode elongation in chrysanthemum. Applied Engineering in Agriculture 14(3):311-316.
22. *Jacobson, B.M. and D.H. Willits. 1998. Developing relationships between environmental variables and stem elongation in chrysanthemums. Trans of ASAE 41(2):825-832.
23. Peet, M. M., D. H. Willits and R. Gardner. 1997. Response of Ovule Development and Post-Pollen Production Processes in Male-Sterile Tomatoes to Chronic, Sub-Acute High Temperature Stress. J. Exp. Bot. 48:101-112.
24. Peet, M.M. and D.H. Willits. 1995. Role of excess water in tomato fruit cracking. Hortscience 30(1):6568.
25. *Niedziela, Carl. E., Jr., Paul V. Nelson, Daniel H. Willits and Mary M. Peet. 1993. Short-term salt-shock effects on tomato fruit quality, yield and vegative prediction of subsequent fruit quality. J of the Amer Soc of Hort Sci 118(1):12-16
26. *Tripp, K.E., *W.K. Kroen, M.M. Peet, and D.H. Willits. 1992. Fewer whiteflies found on CO₂-enriched greenhouse tomatoes with high C : N ratios. HortScience 27:1079-1080.
27. Willits, D.H., P.V. Nelson, M.M. Peet, M.A. Depa and J.S. Kuehny. 1992. Modeling nutrient uptake in chrysanthemum as a function of growth rate. J. Am. Soc. Hort. Sci. 117:769-774.
28. *Tripp, K.E., M.M. Peet, D.H. Willits, D.M. Pharr. 1991. CO₂-enhanced foliar deformation of tomato: relationship to foliar starch concentration. J of Amer Soc of Hort Sci 116:876-880.
29. *Tripp, Kim E., Mary M. Peet, D. Mason Pharr, Daniel H. Willits, Paul V. Nelson. 1991. CO₂-enhanced yield and foliar deformation among tomato genotypes in elevated CO₂ environments. Plant Physiol 96:713-719.
30. *Kuehny, J.S., M.M. Peet, P.V. Nelson, and D.H. Willits. 1991. Nutrient dilution by starch in CO₂ enriched chrysanthemum. J of Exp Botany 42(239):711- 716.
31. *Stoop, Johan M.H., Dan H. Willits, Mary M. Peet, and Paul V. Nelson. 1991. Carbon gain and photosynthetic response of chrysanthemum to PPFD cycles. Plant Physiol 96:529-536.
32. *Stoop, J.M., M.M. Peet, D.H. Willits and P.V. Nelson. 1990. Photosyn thetic dynamics in Chrysanthemum in response to single step increases and decreases in photon flux density. Plant Physiol 94, 46-53.
33. Willits, D.H. and M.M. Peet. 1989. Predicting yield responses to different CO₂ enrichment schemes: cucumbers and tomatoes. Agricultural and Forest Meteorology, 44:275-293.
34. *Bowers, Crowell G., Jr., Daniel H Willits and Henry D. Bowen. 1988. Comparison of temperature correction methods for hot wire anemometers. Transactions of the ASAE 31(5):1552-1555 (Technical Note).
35. Willits, D.H. and M.M Peet. 1987. Factors affecting the performance of rockstorages as solar energy collection/storage systems for greenhouses. Transac- tions of the ASAE 30(1):221-232.
36. *Bottcher, R.W. and D.H. Willits. 1987. Numerical computation of two dimensional flow around and through a peaked roof building. Transactions of the ASAE 30(2):469-475.
37. Peet, M.M. and D.H. Willits. 1987. Greenhouse CO₂ enrichment alternatives: Effects of increasing concentration or duration of enrichment on cucumber yield. J. Amer. Soc. Hort. Sci. 112(2):236-241.
38. *Abbott, J.D., M.M. Peet, D.H. Willits, D.C. Sanders, and R.E. Gough. 1986. Effects of irrigation frequency and scheduling on fruit production and radial fruit cracking in soil and soilless bag-cultured greenhouse tomatoes. Scientia Hortic. 28:209-217.
39. *#Bowers, C.G., Jr., D.H. Willits, and H.D. Bowen. 1986. Criteria for determining bouyancy effects on turbulent forced convection in an asymetrically heated horizontal channel. Transactions of the ASAE 29(2):550-555.
40. *#Bottcher, R.W., D.H. Willits, and G.R. Baughman. 1986. Experimental analysis of wind ventilation of poultry buildings. Transactions of the ASAE 29(2):571-578.
41. Willits, D.H. 1986. The effect of different fan control strategies on unit heater performance. Applied Engineering in Agriculture 2(2):174-178.
42. *Abbott, J.D., M.M. Peet, D.H. Willits, and R.E. Gough. 1985. Water management of greenhouse tomatoes. HortScience 20(4):688-690.
43. Willits, D.H., P. Chandra and M.M. Peet. 1985. Modeling solar energy storage systems for greenhouses. J. of Agri. Eng. Res. 32:73-93.
44. *Brumfield, R.G., A.J. Coutu, P.V. Nelson, D.H. Willits, R.S. Sowell, R.G. Anderson. 1984. Determining marketing efficiency of floricultural production firms by market channel, market period and size of firm. J. Amer. Soc. Hort. Sci. 109:578-83.
45. Peet, M.M. and D.H. Willits. 1984. CO₂ enrichment of greenhouse tomatoes using a closed loop heat storage: Interactions with cultivar and level of nitrogen supply. Scientia Horticulturae 24(1):21-32.
46. *Delwiche, S.R. and D.H. Willits. 1984. The effect of condensation on heat transfer through polyethylene film. Trans. of the ASAE 27(5):1476-1482.
47. *Karnoski, T.C., D.H. Willits and R.W. Skaggs. 1984. Porous bulbs to control water contents in container media. Hortscience 19(3):393-95.
48. Peet, M.M. and D.H. Willits. 1982. The effect of density and postplanting fertilization on response of lettuce to CO₂ enrichment. Hortscience 17(6):948-49.
49. Rohrbach, R.P, J.E. Franke and D.H. Willits. 1982. A firmness sorting criterion for blueberries. Trans. of the ASAE 25(2):261-65.
50. Chandra, P. and D.H. Willits. 1981. Pressure drop and heat transfer characteristics of air-rockbed thermal storage systems. Solar Energy 27(6):547- 53.
51. *Brumfield, R.G., P.V. Nelson, A.J. Coutu, D.H. Willits and R.S. Sowell. 1981. Cost of producing Easter lillies in three firm sizes and two market channels. J. Amer. Soc. Hort. Sci. 106(5):561-64.
52. *Brumfield, R.G., P.V. Nelson, A.J. Coutu, D.H. Willits and R.S. Sowell. 1981. Overhead costs of greenhouse firms differentiated by size of firm and market channel. NCARS Technical Bulletin No. 269, North Carolina Agricultural Research Service, Raleigh, NC.
53. Willits, D.H., P. Chandra, and C.H. Miller. 1981. A solar energy collection/storage system for greenhouses: observed and simulated performance. (Paper no. 6405 of the Journal Series of the NCARS). In Agricultural Energy, pub by American Society of Agricultural Engineers, St. Joseph, MI 2:524-29.
54. Willits, D.H., T.K. Karnoski, and E.H. Wiser. 1980. A microputer based control system for greenhouse research: Part II. Software. Trans. of the ASAE 23(3):693-98.
55. Willits, D.H., T.K. Karnoski, and W.F. McClure. 1980. A microprocessor based control system for greenhouse research: Part I. Hardware. Trans. of the ASAE 23(3):688-92,698.
56. Willits, D.H. and E.H. Wiser. 1980. Interrupting Basic. Kilobaud/- Microcomputing (Paper no. 5590 of the Journal Series of NCARS), Jan:180-84.
57. Chen, L.H., D.H. Willits and R.S. Sowell. 1978. Computer simulation of nursery potting operations. Trans. of the ASAE 21(3):427-30.
58. Willits, D.H., I.J. Ross, G.M. White and H.E. Hamilton. 1976. A mathematical drying model for porous material: Part II Experimental Results. Trans. of the ASAE 19(3):562-68.
59. Willits, D.H., I.J. Ross, G.M. White and H.E. Hamilton. 1976. A mathematical drying model for porous material: Part I Theory. Trans. of the ASAE 19(3):556-61.
60. Willits, D.H. and I.J. Ross. 1975. An automatic weighing system for use in drying studies. Trans. of the ASAE 18(4):711-13.
61. Willits, D.H., J.M. Myers and I.J. Ross. 1968. A low pressure pelleting process for citrus pulp. Trans. of the ASAE 12(4):443-447.

Papers, Proceedings, Abstracts and Reports

1. Willits, D. H., T. Meir, J. Tanny, M. M. Peet, C. Shabtai, and M. Eli. 2006. Comparing the performance of naturally ventilated and fan-ventilated greenhouses. BARD Final Scientific Report US-3189-01, Bet Dagan, 179 pages.
2. Willits, D.H., C.A. Yunker and S. Li. 2006. Air Exchange Rates in a Naturally Ventilated Greenhouse using Different Vent Configurations. Paper no. 064095 presented to the 2006 Annual Meeting of ASABE, Portland, OR.
3. *Li, S., D. Willits and C. Yunker. 2005. Experimental Study on Fogging System in Naturally Ventilated Greenhouses. Paper No. 054139 presented to the annual meeting of the ASAE, Tampa, FL.
4. Willits, D. and S. Li. 2005. A Comparison of Naturally Ventilated vs. Fan Ventilated Greenhouses in the Southeastern US. Paper No. 054155 presented to the annual meeting of the ASAE, Tampa, FL.
5. Harlow, C., Peet, M. Ponce, A.K., Cheng, J., Willits, D. and M. Casteel. 2003. Utilizing a greenhouse tomato crop to recover bio-resources from swine waste. ASHS-2003 Centennial Conference October 3-6, 2003, Providence, RI. P. 729-730. HortScience 38(5) August 2003 (poster presentation).
6. Cheng, J., T. E. Shearin, M. M. Peet, and D. H. Willits. 2003. Utilization of Treated Swine Wastewater for Greenhouse Tomato Production. Proceedings of the 4th International Symposium on Wastewater Reclamation and Reuse, November 12-14, 2003, Mexico City, Mexico.
7. Cheng, J., M. M. Peet, and D. H. Willits. 2003. Ambient temperature anaerobic digester and greenhouse for swine waste treatment and bioresource recovery at Barham farm. Proceedings of the 2003 North Carolina Animal Waste Management Workshop, October 16-17, 2003, Durham, NC, USA.
8. Shearin, T. E., J. Cheng, M. M. Peet, and D. H. Willits. 2003. Utilization of nutrients in anaerobically-pretreated swine wastewater for greenhouse tomato production. Proceedings of the Ninth International Symposium on Animal, Agricultural and Food Processing Wastes (ISAAFPW), October 12-15, 2003, Durham, NC, USA.
9. Willits, D.H., J.M. Marbis, J. Cheng, M.M. Peet, T. Shearin. 2003. Waste Heat Utilization in a Greenhouse Used for the Removal of Nutrients from a Swine Waste Stream. Paper no. 034043 presented to the annual meeting of ASAE, Las Vegas, Nevada.
10. Willits, D. H. 2003. The Penman-Monteith Equation As a Predictor of Transpiration in a Greenhouse Tomato Crop. Paper no. 034095 presented to the annual meeting of ASAE, Las Vegas, Nevada.
11. Willits, D. H. 2002. The effect of shade cloth temperature on the cooling efficiency of shade cloths in greenhouses. Paper no. 024113 presented to the annual meeting of ASAE, Chicago, IL.
12. Gurjer, Y. R. and D. H. Willits. 2002. The use of heat pumps for the heating and cooling of greenhouses. Paper no. 024235 presented to the annual meeting of ASAE, Chicago, IL.
13. Cheng, J., Peet, M., Willits, D. and Pace, J. 2001. Integrated Farming for Sustainable Agriculture. International Conference on Agricultural Science and Technology, November 7-9 2001, Beijing, China.
14. Cheng, J., Pace, J., Peet, M., Willits, D. and T. Shearin. 2001. Using a greenhouse tomato crop to recover the nutrients from swine wastewater. Animal and Poultry Waste Management Center International Symposium on Agricultural Production and Environmental Issues. Oct. 3-5, RTP, NC.
15. Peet, M.M., Ponce, K., Willits, D.H., Cheng, J. 2001. Bioremediation of Swine Waste using Greenhouse Tomatoes: A Systems Approach. 98th Conference of the American Society for Horticultural Science. July 22-25, 2000, Sacramento, CA. HortScience 36:472 (poster presentation #465 at ASHS and also presented at Sustainable Ag. Conference, Rock Hill, SC, Nov. 2-4)
16. Willits, D. H. 2000. Design of environmental control systems for greenhouses: A comparison of four engineering standards plus input from the industry. ASAE Paper no. 00-4060, pp 18.
17. Willits, D. H. 2000. The effect of ventilation rate, evaporative cooling, shading and mixing fans on air and leaf temperatures in a greenhouse tomato crop. ASAE Paper no. 00-4058, pp 18.
18. Seginer, I., D. H. Willits, M. Raviv and M. M. Peet. 2000. Transpirational cooling of greenhouse crops. BARD Final Scientific Report IS-2538-95R, Bet Dagan.
19. Willits, D.H. 1999. The effect of canopy density, ventilation rate and evaporative cooling on the transpiration of a greenhouse tomato crop. ASAE Paper no. 99-4227, pp 18.
20. Peet, M. M., S. Sato, D. Willits and R.G. Gardner. 1998. Critical period for sensitivity to heat stress in tomatoes. Proceedings, 27th National Agricultural Plastics Congress. Feb. 18-21, 1998. Tucson, Arizona. ed.
21. Willits, D. H. and D. A. Bailey. 1996. The effect of alternative night cooling treatments on the warm weather production of chrysanthemum. Paper no. 964004 presented to the annual meeting of the ASAE, Phoenix, AZ.
22. Willits. D. H. 1995. Effect of cloth characteristics on mistedshade cooling performance. Paper no. 954490 presented to the annual meeting of the ASAE, Chicago, IL.
23. Willits, D. H. and D. A. Bailey. 1994. Night cooling as a means of improving warm weather chrysanthemum production: The effect of night temperature on growth and flower development in mums. Paper no. 94-4072 presented to the annual summer meeting of the ASAE, Kansas City, MO.
24. Peet, M.M. and D.H. Willits. 1994. High night temperature effects on tomato: Interactions with developmental stage and season. In: Plant Stress in the Tropical Environment. Proceedings of a Workshop held in KailuaKona, Hawii on Sept 2025, 1992. Ed by T. Davenport and M. Harrington, E. O. Painter Printing Co., Homestead, FL, 118122.
25. Willits, D. H., P. V. Nelson, M. M. Peet, M. A. Depa and J. S. Kuehny. 1993. Modeling chrysanthemum growth rates as a function of PPF, CO₂ and Temperature. Paper no. 93-4050 presented to the ASAE Summer Meeting, Spokane, WA.
26. Willits, D. H. and M. M. Peet. 1993. The effect of evaporative cooling on the efficiency of external greenhouse shade cloths. Paper no. 93-4042 presented to the ASAE Summer Meeting, Spokane, WA.
27. Peet, M.M. and D.H. Willits. 1992. High nighttime temperatures decrease fruitset and yield of greenhouse tomatoes. HortScience 27:596 (abstract).
28. Willits, D.H. and M.M. Peet. 1992. Nighttime cooling using heat pumps in warm-weather greenhouse tomato production. Paper no. 92-4005 presented to the ASAE Summer Meeting, Charlotte, NC.
29. Willits, D.H., P.V. Nelson, M.M. Peet, M.A. Depa and J.S. Kuehny. 1992. Nutrient uptake in chrysanthemum as affected by light, CO₂ level and age. Paper no. 92-4030 presented to the ASAE Summer Meeting, Charlotte, NC.
30. Peet, M.M., D.H. Willits, K.E. Tripp, W.K. Kroen, D.M. Pharr, M.A. Depa and P.V. Nelson. 1991. CO₂ enrichment responses of chrysanthemum, cucumber and tomato: photosynthesis, growth, nutrient concentrations and yield. In: Indo- United States Workshop on Impact of Global Climatic Changes on Photosynthesis and Plant Productivity, ed. by Y.P. Abrol, Govindjee, P.N. Wattal, D.R. Ort, A. Gnanam and A.H. Teramura. New Delhi.
31. *Sipal, C.A., D.H. Willits and R.S. Sowell. 1991. Economics of rockbed cooling. Paper no. 91-4044 presented to the summer meeting of ASAE, Albuquerque, NM.
32. *Jacobson, B.M., D.H. Willits and P.V. Nelson. 1991. Measuring diurnal internode elongation in chrysanthemums. Paper no. 91-4046 presented to the summer meeting of ASAE, Albuquerque, NM.
33. Willits, D.H., I. Ahmad and M.M. Peet. 1991. A model for greenhouse cooling. Paper no. 91-4041 presented to the summer meeting of ASAE, Albuquerque, NM.
34. *Tripp, K.E., M.M. Peet, D.M. Pharr, D.H. Willits. 1990. Enrichment of tomatoes: relationship of foliar stress symptoms to starch concentration and carbon exchange rates. Plant Physiol 93, 56 (abstract).
35. Peet, M.M., D.H. Willits, K.E. Tripp, D.M. Pharr, M.A., Depa, J.S. Kuehny, P.V. Nelson. 1990. Case studies of CO₂ enrichment responses: chrysanthemum, cucumbers and tomatoes. Proceedings of Global Climate Change Symposium, NCARS Bul. 479, North Carolina Agricultural Research Service, NCSU, Raleigh, NC.
36. Willits, D.H., M.M. Peet, M. Depa, J.K. Kuehny and P.V. Nelson. 1990. Modulation of nutrient uptake in chrysanthemum by irradiance, CO₂, season, and developmental stage. in British Plant Growth Regulator Group Monograph 20, "Mechanisms of plant perception and response to environmental stimuli", ed. by T.H. Thomas, pub by The British Society for Plant Growth Regulation.
37. Willits, D.H. and R.P. Rohrbach. 1989. One approach to local area networking an academic department. Paper no. 89-3506 presented to the winter meeting of ASAE, New Orleans, LA, December 12-15, 1989.
38. Willits, D.H., R.W. Bottcher, J.L. Marshall, and M.R. Overcash. 1989. Factors affecting the performance of external shade cloths. Paper no. 89-4034 presented to the summer meeting of ASAE, Quebec, Quebec, Canada, June 25-28, 1989.
39. *Church, G.A., III, and D.H. Willits. 1989. Flow and energy solution for rockbed design and control. Paper no. 89-4037 presented to the summer meeting of ASAE, Quebec, Quebec, Canada, June 25-28, 1989.
40. *Stoop, J.M., D.H. Willits, P.V. Nelson, and M.M. Peet. 1989. Photosynthetic dynamics in chrysanthemum in response to step changes in photon flux density. Paper presented to the Southern Section of the American Society of Plant Physiol., Feb 5-9, Athens, Ga.
41. *Tripp, K.E., M.M. Peet, D.M. Pharr, D.H. Willits. 1989. CO₂ toxicity in greenhouse tomato: interaction with carbohydrate metabolism. Plant Physiol. Supp., 89:6 (abstract)
42. *Tripp, K.E., M.M. Peet, D.M. Pharr, D.H. Willits. 1988. CO₂ toxicity in greenhouse tomatoes: role of carbohydrate metabolism. Hortscience 23: 154-155 (abstract)
43. *Kuehny, Jeff, Mary Depa, Paul Nelson, Dan Willits, and Mary Peet. 1987. Dependence of nutrient uptake in Chrysanthemum morifolium on growth rate as influenced by CO₂ and irradiance. Hortscience 22(5):1095 (abstract)
44. Peet, Mary, Daniel Willits, Mary Depa, and Paul Nelson. 1987. CO₂ and irradiance level effects on photosynthesis, nutrient uptake and growth of chrysanthemum. Plant Phys. 83(4):33 (abstract).
45. *Depa, M.A., P.V. Nelson, D.H. Willits, M.M. Peet. 1986. Effect of CO₂ level and light intensity on nutrient uptake in chrysanthemum. Hortscience 21(3):763 (abstract).
46. Peet, M.M., D.H. Willits, M.A. Depa, and P.V. Nelson. 1986. Development of a database for modeling CO₂ and light effects on photosynthesis and growth in Chrysanthemum moriflorium. Hortscience 21(3):887 (abstract).
47. *Bottcher, R.W., D.H. Willits, and M.B. Timmons. 1985. Predicting wind ventilation by the pressure coefficient method. Paper no. 85-4010 presented to the 1985 Summer Meeting of ASAE, June, East Lansing, Michigan.
48. Peet, M.M. and D.H. Willits. 1985. Photosynthetic and stomatal response of tomatoes and cucumbers to long term CO₂ enrichment. Plant Physiology (Supplement) 77:4.
49. Peet, M.M. and D.H. Willits. 1984. Source/sink factors affecting cultivar response to CO₂ enrichment. Acta Horticulturae Vol 162:121-128.
50. Willits, D.H. and M.M. Peet. 1984. CO₂ enrichment in solar energy collection/storage systems for greenhouses. Proceedings of the 4th Annual Solar and Biomass Energy Workshop, USDA-DOE, April 17-19, Atlanta, GA.
51. *Delwiche, S.R. and D.H. Willits. 1983. The effect of condensation on heat transfer through polyethylene film. Paper No. 83-4017 presented to the 1983 Summer Meeting of ASAE, June 26-29, Bozeman, Montana.
52. Peet, M.M. and D.H. Willits. 1982. Use of a CO₂ enriched solar energy collection/storage greenhouse for vegetable production in the Southeast. Abstract for the 79th Annual Meeting of AHS, Aug. 8-13, Ames, Iowa.
53. Sowell, R.S., D.H. Willits, P.V. Nelson, R.G. Brumfield, D.G. Sanford and A.J. Coutu. 1982. Optimizing greenhouse production management decisions using linear programming. Paper No. 82-504 presented to the 1982 Summer Meeting of ASAE, June 27-30, Madison, Wis.
54. Willits, D.H. and M.M. Peet. 1981. CO₂ enrichment in a solar energy collection/storage greenhouse. Paper No. 81-4525 presented to the 1981 Winter Meeting of ASAE, Dec. 15-18, Chicago, IL.
55. Willits, D.H., M.M. Peet and P. Chandra. 1981. The effect of transpiration on the solar collection potential of a greenhouse. Paper No. 81-4041 presented to the 1981 Summer Meeting of ASAE, June 21-24, Orlando, FL.
56. *Karnoski, T.C., D.H. Willits and R.W. Skaggs. 1981. Porous ceramic bulbs as a means of controlling moisture levels in container media. Paper No. 81- 1085 presented to the 1981 Summer Meeting of ASAE, June 21-24, Orlando, FL.
57. *Brumfield, R.G., P.V. Nelson, A.J. Coutu, D.H. Willits and R.S. Sowell. 1981. Marketing costs of floricultural firms by market channel. Presented to the 78th Annual Meeting of the Amer. Soc. for Hort. Sci., Aug. 9-14, 1981.
58. Rohrbach, R.P., J.E. Franke and D.H. Willits. 1980. A proposed firmness sorting criterion for blueberries. Paper No. 80-1530 presented to the 1980 Winter Meeting of ASAE, Dec. 2-5, Chicago, IL.
59. Rogers, H.H., C.H. Miller, D.H. Willits and R.J. Downs. 1980. Kinetic measurement of whole plant photosynthesis: light and temperature. Suppl. to Plant Physiol.: 83 (Annual Meeting of American Society of Plant Physiol., Washington State Univ., Pullman, Aug. 3-7).
60. Chandra, P. and D.H. Willits. 1980. Thermal behavior of a greenhouse collection/storage system. Paper No. 80-4025 presented to the 1980 Summer Meeting of ASAE.
61. Rohrbach, R.P., D.H. Willits and J.E. Franke. 1979. Blueberry firmness investigations using a microcomputer. Proc. of North American Blueberry Research Workers Conf., Oct. 16-18, Univ. of Arkansas, Fayetteville.
62. Willits, D.H., P. Chandra and C.H. Miller. 1979. Performance of collection storage system for greenhouses. Proc. 4th Annual Conf. on Solar Energy for Heating Greenhouses and Greenhouse-Residence Combinations, April 1-4, Piscataway, NJ, pp. 73-82.
63. Willits, D.H., T.C. Karnoski, W.F. McClure and E.H. Wiser. 1978. A microprocessor-based control system for greenhouse environment. Paper No. 78-5547 presented to the 1978 Winter Meeting of ASAE, Dec. 18-20, Chicago, IL.
64. Chen, L.H., D.H. Willits and R.S. Sowell. 1977. Computer simulation of nursery potting operations. Paper No. 77-1063 presented to the 1977 Summer Meeting of ASAE, June 26-29, Raleigh, NC.
65. Willits, D.H., C.G. Bowers, Jr., P.V. Nelson and B.K. Huang. 1976. A solar energy storage system for greenhouses. Paper No. 76-3507 presented to the 1976 Winter Meeting of ASAE, Dec. 14-17, Chicago, IL.
66. Willits, D.H. 1976. Computer analyses of potting operations. Proceedings of the Southern Nurseryman s Association Research Workers Conference, July 31- August 2, Atlanta, GA.
67. Willits, D.H., I.J. Ross, G.M. White, H.E. Hamilton. 1974. A mathematical drying model for manure based on the concept of a receding evaporative interface. Paper No. 74-4512 presented to the 1974 Winter Meeting of ASAE, Dec. 10-13, Chicago, IL.
68. Willits, D.H. and I.J. Ross. 1974. An automatic weighing system for use in drying studies. Paper No. 74-5012 presented to the 1974 Summer Meeting of ASAE, June 23-26, Stillwater, OK.
69. Willits, D.H., J.M. Myers and I.J. Ross. 1968. A low pressure pelleting process for citrus pulp. Paper No. 68-331 presented to the 1968 Summer Meeting of ASAE, June, Logan, UT.

Popular Articles and Newsletters

1. Willits, Daniel H. 2005. Improve your cooling. GMPro - Greenhouse Management and Production 25(4):26-28.
2. Willits, Dan H. and Bailey, Douglas A. 1999. The effects of night temperature on chyrsanthemum flowering. Greenhouse Product News 9(2):32-33,42.
3. Willits, D. H. 1994. Misting external shade cloths Part II: Does it matter what kind of cloth? North Carolina Flower Growers' Bulletin, Vol 39, No. 6, December, pp15.
4. Willits, D. H and M. M. Peet. 1994. Misting external shade cloths; Part I: Relief from the heat? North Carolina Flower Growers' Bulletin, Vol 39, No. 2, April, 1994, pp15.
5. Willits, D.H. and M.M. Peet. 1993. Misting external shade cloths -- relief from the heat? North Carolina Greenhouse Vegetable Growers' Association Newsletter, NCGVGA, Inc.
6. Willits, D.H. 1993. Greenhouse cooling. North Carolina Flower Growers' Bulletin 38(2):15-18.
7. Willits, D.H. and M.M. Peet. 1993. Effect of night cooling on warm weather yield and fruit set in greenhouse tomato. N.C. Greenhouse Vegetable Growers Assoc Newsletter, March, 1993.
8. Peet, M. M. and D. H. Willits. 1992. Tomato Fruit Cracking. Greenhouse Grower. Spring 1992.
9. Willits, D.H. 1992. Greenhouse cooling. N.C. Greenhouse Vegetable Growers Association Newsletter, June, 1992.
10. Willits, D.H. 1991. Greenhouse shading. North Carolina Flower Growers' Bulletin 36(5):8-10.
11. Willits, D.H. 1991. Greenhouse engineering research at NCSU. North Carolina Flower Growers' Bulletin 36(4):1-4.
12. Peet, M.M. and D.H. Willits. 1989. CO₂ enrichment pays. American Vegetable Grower, August, 1989.
13. Peet, M.M, D.H. Willits, and E.B. Polling. 1988. Rockwool: Promising in tomato/strawberry studies. American Vegetable Grower, June, pp 54,56,58.
14. Willits, D.H. 1988. Improve unit heater efficiency. Greenhouse Grower, April, pp 30,32,35.
15. Willits, D.H. and M.M. Peet. 1987. Greenhouses and rockbeds: are they compatible? Greenhouse Grower, August, pp 88-91
16. Willits, D.H. 1983. Computer control: Is it time? North Carolina Flower Growers Bulletin 27(2):2-5.
17. *Brumfield, R.G., P.V. Nelson, A.J. Coutu, R.G. Anderson, D.H. Willits and R.S. Sowell. 1982. Improve your marketing efficiency by analyzing cost differences. Florists Review, Sept, 2:14-15,37-38.
18. Willits, D.H. 1982. Improving unit heater efficiency. North Carolina Flower Growers Bulletin 26(6):1-4.
19. Dodson, J.D., D.H. Willits, and E.H. Wiser. 1980. Microcomputers: Basic facts and terminology. North Carolina Extension Service AM-25, N.C. State Univ., Raleigh, NC, May.
20. Willits, D.H. 1975. Heating greenhouses with solar energy. North Carolina Flower Growers Bulletin 19(5):1-4.

* - Graduate student

# - Asae paper award

Oral Presentations:

1. Willits, D. H. 2003. Controlling the Greenhouse Environment. Guest lecture presented in HS 590C, Special Problems in Greenhouse Vegetable Production, 2/11/03.
2. Willits, D.H. 2002. Environmental control in greenhouses. Presentation to the NC Greenhouse Vegetable Growers Meeting, Wake County Agricultural Services Center, Raleigh, NC, Oct 7, 2002.
3. Willits, D. H. 2001. Greenhouse Cooling. Guest lecture presented in HS 590C, Special Problems in Greenhouse Vegetable Production.
4. Willits, D.H. 2001. Computer Control in Greenhouses. Presentation to the NC Greenhouse Vegetable Growers Meeting, Brownstone Hotel, Raleigh, NC, Oct 24, 2001.
5. Willits, D.H. 1999. Greenhouse cooling: trade-offs, constraints and recommendations. Presentation to the NC Greenhouse Vegetable Growers Meeting, Oct. 28, Raleigh, NC.

Copyright ©2008 by D. H. Willits