*3.4. Growth and Yield Parameters*

Plants in the T90 treatments were taller than the plants in the Tcontrol, T30, and T60 treatments, with a mean plant height of 134.6 cm for plants in the T90 treatment, while the shortest plants (113.3 cm) were in the T30 treatment. An inverse relationship was observed between the mean plant height and WTD, which was similar to the relationship between the WTD and the groundwater contribution. When the water level was increased from 90 to 60 cm (measured from the soil surface) in the lysimeters, the canola plant height decreased from 134.6 to 113.3 cm.

Treatment differences were significant for total biomass, pod weight, and seed weight per plant (Table 4). The highest mean total biomass, pod weight, and seed weight were 22.1, 12.6, and 6.3 gr, respectively, for the T90 treatment. The lowest mean total biomass, pod weight, and seed weight results were 15.1, 9.5, and 4.8 gr, respectively, for the T30 treatment. These results indicate that the shallower water table depth decreased canola harvesting. Overall, the statistical results suggest a negative correlation between the canola plant growth and the yield parameters and WTD. A similar correlation between the WTD and crop harvesting results was reported by Mejia et al. [8]. According to the 2 year lysimeter experiment results, corn and soybean grain yield weights increased when the WTD decreased from 50 cm to 75 cm [8].

Plants in the control treatment consumed the most water (Tables 2 and 3), while plants in the T90 treatment had the highest yield values compared to other treatmnets (Table 4). As explained earlier, plants inTcontrol used the optimum amount of irrigation water, 740 mm, while plants in T90 consumed 501 mm of water from the groundwater. However, better growth and yield results were obtained from plants in the T90 treatment.


**Table 4.** Statistical analysis of the canola growth and yield parameters.

Note: Lowercase letters; a, b, c, and <sup>d</sup> show statistical significance at *p* = 0.05. The values followed by the same letter in each column are not significantly different.
