Water Use Efficiency Lettuce
This study investigated the effect of Seasol, a seaweed extract, on lettuce growth and water use efficiency under different irrigation regimes. The results showed that water-stressed treatments produced reduced yields compared to standard irrigation treatments, indicating successful manipulation of plant growth through irrigation volumes. The application of Seasol improved the water use efficiency of lettuce plants, as indicated by increased fresh and dry lettuce head weights under 60% irrigation. Without Seasol applied, there was a statistically significant (p<0.05) drop in fresh weight of 30.8g or 20.5% from standard 100% irrigation rate to 60% irrigation rate. However, there was a non-statistically significant drop in fresh weight of 4.2g or 2.8% from standard irrigation rate without Seasol to 60% irrigation rate with Seasol. The treated lettuce also had longer, heavier roots and a consistently higher chlorophyll content compared to untreated lettuce, indicating improved drought resistance.
The post-trial leaf tests showed lower concentrations of nitrate and total nitrogen in Seasol treated lettuce under water stress, likely due to nutrient dilution. Overall, the results suggest that Seasol treatment can counteract the negative effects of water stress on lettuce growth. These findings are consistent with previous research on the use of seaweed extracts to improve plant growth under drought stress.
