Monday, November 13, 2006

Improvement of water use efficiency and yield of greenhouse tomato using matric potential sensor.

Jean Caron1, Isabelle Lemay2, Martine Dorais3, and Steeve Pepin2. (1) Dep. des Sols, Univ. Laval, Pavillon Comtois, Pavillon Comtois, Quebec, QC G1K 7P4, CANADA, (2) Universite Laval, Ste-Foy, QC G1K 7P4, Canada, (3) Agriculture et agroalimentaire Canada, Ste-Foy, QC G1K 7P4, Canada

For many years, environmental and economical constraints have forced growers to look for new substrates for replacing rockwool in greenhouse tomato production. Peat sawdust mixes have long been proposed as organic alternatives to rockwool, with however lower yields likely linked to irrigation and aeration problems. The development of high performing and easy to use matric potential sensors has provided an opportunity to refine this irrigation strategy.  The objective of this study was to investigate the zone of hydric comfort of actively growing tomato plant to define appropriate irrigation setups and then to use these setups to grow tomato in comparison with rockwool. Defining new setups appropriate to 2 :1 (v/v) sawdust:peat substrate allowed total and marketable yield increases of 10.5 % and 10.3 % respectively in comparison with rockwool, without reducing tomato quality. Hence, an adapted irrigation strategy could allow growers to use a sustainable growing media, cheaper than rockwool while increasing their yield and economical performances.