The effect of water supply on bio-morphological and plant-physiological parameters of tomato transplants cultivated in wood fiber substrate

Recently the use of the mixture with wood fiber substrates for cultivation of vegetable transplants has received increasing attention. Several experim ents were conducted to investigate the effect of water supply on bio-morpho logical and plant-physiological parameters of tomato transplants cultivated in pure wood fiber substrates in order to optimize cultivation. Optimal growth of transplants in these substrates requires high moisture le vels. Comparing time-dependent with water-tension-dependent irrigation (phi = -30 hPa) showed that almost identical bio-morphological plant characteri stics were achieved. In an ebb/flood system, irrigation pulses are recommen ded at phi = -30 hPa for better leaf morphological parameters and optimal r oot development of tomato transplants in a coarse substrate. Measurements o f free proline in plants grown under these irrigation levels support these results. Critical water tension for irrigation pulses and content of free proline in tomato transplants were closely correlated (r(2)=0.95).