Abstract:
Plants of lettuce (Lactuca sativa L. cv Great Lakes 118) were irrigated by different levels of
NO3NH4 as source of nitrogen and NaCl as source of salinity to investigate the effect of addition
nitrogen on plant growth under salinity condition. Three levels of Nitrogen (N): 0, 50 and 100
ppm were prepared from 0, 145 and 285 ppm of NO3NH4. Four levels of Salinity: 500 (fresh
water), 700, 900 and 1100 ppm were prepared by adding 0, 200, 400 and 600 ppm of NaCl in
fresh water. The leaf numbers (LN), leaf area (LA), specific leaf weight (SLW), head fresh
weight (HFW), head dry weight (HDW) and water content of leaves (WC) were measured for
each treatments at the end of the experiment. The results indicate that the lettuce used did not
appear to be significantly affected by the high level of salinity applied in this experiment. On the
other hand, the addition of nitrogen in the form of NO3NH4 had a positive effect on the growth of
plants under salinity conditions, and appears to prevent the toxicity of the plant from Na+
and Cl.
We conclude that lettuce plants have shown a reasonable degree of tolerance to irrigation water
salinity when specific levels of nitrogen fertilization are available |
