Water Use Efficiency

The major emphasis regarding water use efficiency has been in the development of alternative irrigation scheduling systems using sensor-based technology. Participants in this area have included Robert Geneve, Winston Dunwell, Dewayne Ingram, Susmitha Nambuthiri, Amy Fulcher, Sharon Kester and Cary Grable.

A new on-demand irrigation scheduling system has been developed for container-grown nursery plants using an irrigation set point established on the relationship between substrate water content photosynthesis photosynthetic rate. By maintaining the substrate moisture content just above this set point, a crop could be produced using 27% less water than conventional irrigation scheduling, and without adversely impacting quality, or production time. The plant on-demand irrigation scheduling system has since been employed successfully to reduce irrigation inputs on a number of crops including Hibiscus rosa-sinensis, dogwood (Cornus sp.), oakleaf hydrangea (Hydrangea quercifolia), boxwood (Buxus), Deutzia and redbud (Cercis canadensis) without incurring a growth or quality “penalty”.

Publications generated in this project include:

Nambuthiri, S., A. Fulcher, and R.L. Geneve. 2014. Microirrigation systems for pot-n-pot nursery production. In: Microirrigation Management in Trees and Vines. M.R. Goyal and E.W. Harmsen (eds.). Apple Press, Waretown, NJ. pp. 295-109.

Hagen, E, S. Nambuthiri, A. Fulcher, and R.L. Geneve. 2014. Comparing substrate moisture-based daily water use and on-demand irrigation regimes for oakleaf hydrangea grown in two container sizes. Scientia Horticulturae 179:132-139.

Geneve, R.L., S. Nambuthiri, E. Hagen, and A. Fulcher. 2014. Application efficiency for sprinkler irrigated container plants grown under sensor based irrigation scheduling. Acta Horticulturae, in press.

Fulcher, A., J. Buxton and R.L. Geneve. 2012. Using the relationship between container substrate moisture and photosynthesis to schedule irrigation in Hibiscus rosa-sinensis. Scientia Horticultureae 138:221-226.

Fulcher, A. and R.L. Geneve. 2011. Relationship between photosynthesis and substrate moisture for container-grown Hibiscus and Cornus. Acta Horticulturae 922:183-186.

Nambuthiri,S., R. Geneve and A. Fulcher. 2014. Evaluating irrigation scheduling based on daily evapo-transpiration or plant demand of container grown woody plants. Proceedings of Southern Nursery Association Research Conference 58: 290-292.

Nambuthiri, S., R. Geneve, and A. Fulcher. 2013. Evaluating irrigation scheduling based on evapo-transpiration or plant water demand of container grown nursery plants. Proceedings of Southern Nursery Association Research Conference 58: 190-192.

Hagen, E., S. Nambuthiri, A. Fulcher, and R. Geneve. 2012. Comparing substrate moisture-based daily water use and on-demand irrigation regimes for oakleaf hydrangea plants grown in two container sizes. Proc. International Plant Propagators’ Society. 62:161

Fulcher, A. and R.L. Geneve. 2009. Cornus, gas exchange, and drought. Proceedings of Southern Nursery Association Research Conference 54:22-27.

Fulcher, A., R.L. Geneve, J. Buxton, and R. Gates. 2008. The Relationship between photosynthetic activity, container moisture and growth in Hibiscus rosa-sinensis L. Proceedings of Southern Nursery Association Research Conference 53:549-552.