Increasing the efficiency of water use in agriculture
Background
It may be possible to use deficit irrigation to exploit the plant’s long distance signalling networks to enhance water use efficiency in agriculture and increase reproductive crop quality, in part by restricting vegetative crop development and the commitment of resources to this end. As soil dries, shoot water status can be sustained by signalling-induced restrictions in stomatal aperture.
If in addition to this, we can develop genotypes which do not produce chemical leaf growth inhibitors as soil dries or have leaf growth processes that are insensitive to these signals, then we can perhaps also sustain biomass accumulation and yield of vegetative plant parts when water supply for agriculture is restricted. This strategy is dependent on identifying the different chemical signals that limit both stomatal conductance and leaf expansion during drought – if indeed there are different regulators of the two processes.
While decreased plant water use (caused by the limitation to both stomatal conductance and leaf expansion) can allow the plant to husband immediately available water resources, another strategy might be for the roots to explore deeper parts of the soil profile Manipulation of this variable may provide extra water supply to growing shoots and allow maintenance of shoot growth processes at low bulk soil water status.
Publications
- Davies, W.J., Wilkinson, S. and Loveys B. (2002) Stomatal control by chemical signalling and the exploitation of this mechanism to increase water use efficiency in agriculture. New Phytologist 153, 449-460.
- Mingo, D., Theobald, J., Bacon, M.A., Davies, W.J. and Dodd, I.C. (2004) Biomass allocation in tomato plants grown under partial rootzone drying: enhancement of root growth. Functional Plant Biology 31, 971-978
- Davies, WJ, Hartung, W. (2004) Has extrapolation from biochemistry to crop functioning worked to sustain plant production under water scarcity? In, New Directions for a Diverse Planet. Proceedings of the International Crop Science Congress, Brisbane.
- Dodd, I.C., Theobald, J.C., Bacon, M.A. and Davies, W.J. (2006) Alternation of wet and dry sides during partial rootzone drying irrigation alters root-to-shoot signalling of abscisic acid. Functional Plant Biology 33, 1081-1089
- Davies WJ (2006) Responses of Plant Growth and Functioning to Changes in Water Supply in a Changing Climate. In, Plant Growth and Climate Change. Eds. JIL Morison and M Morecroft. Blackwells, Oxford. Pp 96-117.
- Morison, J.I.L., Baker, N.R., Mullineaux, P.M. and Davies (2007) Improving water use in crop production. Phil. Trans. Royal Soc. Special Issue on Sustainable Agriculture 363, 639-658