EVALUATING LEAF WATER POTENTIAL, STOMATAL RESISTANCE AND CANOPY SURFACE TEMPERATURE OF TOMATOES AS INDICES FOR IRRIGATION TIMING
Usefulness of leaf water potential, stomatal resistance, and canopy surface temperature as indices for irrigation timing of tomatoes was studied. A mid-plot line source sprinkler lateral insured a wide range of irrigation levels ranging from replacement of soil moisture deficit during each irrigation to essentially a zero application level. While the plant was affected by water stress, and dry matter and fruit production was reduced, the stomatal resistance to gaseous exchange and generally canopy surface temperature were not affected. However by late season leaf water potential was 3 bar more negative in the dry treatment. The results suggest that measurements of leaf water potential or stomatal resistance do not offer a sensitive enough index for timing of irrigation at least with currently available commercial instruments. In most of the measurements canopy surface temperature showed little difference between irrigation levels, suggesting similar lack of sensitivity of this parameter.
Kamgar, Ali A., Henderson, D. W. and Pruitt, W. O. (1980). EVALUATING LEAF WATER POTENTIAL, STOMATAL RESISTANCE AND CANOPY SURFACE TEMPERATURE OF TOMATOES AS INDICES FOR IRRIGATION TIMING. Acta Hortic. 100, 181-192