TABLE 1.

Plant dry weight, roots dry weight, shoot dry and fresh weight, harvest index, relative growth rate (RGR), shoot dry weight standard deviation (SD) and shoot dry weight standard deviation percentage of hydroponically-grown lettuce plants in Test 1 and Test 2.

Test	Plant dry weight (g plant–1)	Roots dry weight (g plant–1)	Shoot dry weight (g plant–1)	Shoot fresh weight (g plant–1)	Harvest index	RGR (mg mg–1 day–1)	Shoot dry weight (SD)	Shoot dry weight (SD%)
Test 1	5.13 ± 0.26	0.73 ± 0.04	4.40 ± 0.23	87.42 ± 4.61	0.86 ± 0.001	0.089 ± 0.003	1.01	23.01
Test 2	12.68 ± 0.35	1.05 ± 0.05	11.63 ± 0.33	278.61 ± 6.19	0.92 ± 0.003	0.083 ± 0.001	1.46	12.59
Student’s t-test	***	***	***	***	***	ns	–	–

All data are expressed as mean ± standard error, n = 20. ns, *** Non-significant or significant at P ≤ 0.001, respectively. SD: standard deviation.