OPTIMIZATION OF IRRIGATION OF ROMAINE LETTUCE (LACTUCA SATIVA L.) CULTIVATED IN MUCK SOIL

In Canada, increasing environmental awareness by field vegetable growers has resulted in significant research efforts to optimize use of water and fertilizers for lettuce production in muck soils.
A growth chamber project was initiated to determine the optimal soil matric potential required for initiating lettuce irrigation during the first stage of growth.
Romaine lettuce transplants (‘Sunbelt’) were seeded in sphagnum peat cubic blocks and grown in greenhouse conditions for 14 days.
They were then transplanted into 84-L plastic containers filled with large undisturbed blocks of either young or decomposed muck soil and placed in a growth chamber.
Metal halide and incandescent lamps supplied a PPF of 500 µmol m^-2 s^-1 for a photoperiod of 16 hours.
Temperatures were maintained at 21°C during the day and at 17°C during the night.
Transplants were drip irrigated whenever 4 different matric potentials were reached (-10, -20, -30 and -50 kPa), as monitored with wireless electronic tensiometers.
Plant fresh weight, leaf number, as well as photosynthesis were measured fourteen days after transplanting.
Optimal lettuce growth was obtained at matric potentials of -32 and -22.5 kPa for young and well decomposed muck soils, respectively.

International Symposium on High Technology for Greenhouse Systems: GreenSys2009

L. Plamondon, L. Gaudreau, A. Gosselin, J. Caron, D. Van Winden, S. Jenni

growth chamber, soil matric potential, yields

https://doi.org/10.17660/ActaHortic.2011.893.133