, Siti Aishah, H.
, Edaroyati Puteri, M. W.and Radziah, O.
Experiments were carried out under rain shelter to investigate the effect of deficit irrigation on
the growth, nutrient element accumulation and water use efficiency of tomato. Tomato of the MT
I variety were transplanted in poly bags and subjected to four (4) different irrigation levels. The
irrigation levels included soil water potential values of 33 Kpa (full irrigation at 100 % field
capacity) as control and deficit treatments of 68, 53 and 39 % of field capacity (FC),
corresponding to soil water potential values of 1319.60, 890.24 and 511.89 Kpa respectively.
Deficit irrigation treatments were imposed from 2 to 14 weeks after transplanting (WAT) and
data collected on plant height, total leaf area, plant dry weight, leaf water potential, stomatal
conductance, net photosynthetic rate, nutrient element accumulation and yield water use
efficiency. The results showed that deficit irrigation treatments significantly reduced all
parameters studied. There was a significant, positive linear relationship between leaf area, dry
weight, leaf water potential, net photosynthetic rate and irrigation levels. Deficit treatments of
68, 53 and 39 % FC reduced leaf water potential by 56, 50 and 35 % and yield water use
efficiency by 38, 22 and 10 % respectively over the control. The effect on the water use
efficiency suggests that sustained deficit irrigation may not be a useful strategy for water
conservation in tomato production under prevailing conditions.