Tomato plant architecture as affected by salinity: Descriptive analysis and integration in a 3-D simulation model

Limited information is available on the effect of salinity on plant architecture; not only on final plant height, number of leaves, and leaf area, but also on plant growth and development from the leaflet to the whole plant scale. Tomato plants (Solanum lycopersicum L. 'Marmara') were grown in greenhouses at four salinity levels (4, 7, 10, and 13 mS.cm(-1)). Plant development (leaf and inflorescence initiation), leaf growth rate, and final leaf dimensions were measured along the stem according to leaf rank and treatment. A decrease in leaflet growth and in the number of leaflets per leaf was associated with a lower growth rate and longer growth period in salinity stressed plants. Stem internode length was also reduced by salinity. At the plant scale, plant height and leaf area decreased with an increase in salinity. These parameters were the main inputs of a 3-D model of plant architecture, which enabled a complete description of plant architecture from the elementary to the canopy scale. This model of plant architecture was evaluated by comparing hemispherical photos of the plant taken with a camera with those generated by the model. The model was used to estimate light interception which should be useful to calculate photosynthesis at the plant scale.