. 2012 Mar 14;110(2):405–414. doi: 10.1093/aob/mcs051

Table 4.

Response of Cotula coronopifolia and Meionectes brownii to aquatic adventitious roots removal at different time intervals (never, once after 14 d, every second day) while under partial and complete submergence

Species	Submergence treatment	Aquatic root removal	RGR (aquatic root mass excluded) (g g⁻¹ d⁻¹)*	Chla in submerged leaves (mg g⁻¹ DM)	Chla in submerged stems (mg g⁻¹ DM)	DM of aquatic roots removed (g DM)	Total DM aquatic roots grown (g DM)
C. coronopifolia	Partial	Never	0·017 ± 0·001^a	1·01 ± 0·78^a	0·29 ± 0·02^a	n.a.	2·539 ± 0·224^a
C. coronopifolia	Partial	Once on day 14	0·008 ± 0·003^b	1·42 ± 0·02^a	0·23 ± 0·03^a	1·196 ± 0·095^a	1·992 ± 0·248^a
C. coronopifolia	Partial	Every 2nd day	0·001 ± 0·001^c	1·23 ± 0·65^a	0·25 ± 0·05^a	0·228 ± 0·075^b	0·243 ± 0·078^b
C. coronopifolia	Complete	Never	0·005 ± 0·003^b	2·68 ± 0·14^b	0·91 ± 0·05^b	n.a.	0·639 ± 0·204^c
C. coronopifolia	Complete	Once on day 14	–0·005 ± 0·003^c	2·14 ± 0·19^c	0·62 ± 0·05^c	0·238 ± 0·018^b	0·490 ± 0·033^c
C. coronopifolia	Complete	Every 2nd day	–0·007 ± 0·005^c	1·88 ± 0·16^c	0·52 ± 0·01^c	0·201 ± 0·046^b	0·219 ± 0·046^b
M. brownii	Partial	Never	0·014 ± 0·001^a	0·89 ± 0·22^a	0·39 ± 0·04^a	n.a.	1·481 ± 0·745^a
M. brownii	Partial	Once on day 14	0·009 ± 0·002^b	0·60 ± 0·12^a	0·30 ± 0·02^a	0·999 ± 0·188^a	1·874 ± 0·625^a
M. brownii	Partial	Every 2nd day	0·007 ± 0·005^b	0·96 ± 0·15^a	0·33 ± 0·09^a	0·340 ± 0·240^b	0·404 ± 0·301^b
M. brownii	Complete	Never	0·022 ± 0·001^c	3·73 ± 0·23^b	1·89 ± 0·17^b	n.a.	1·034 ± 0·456^c
M. brownii	Complete	Once on day 14	0·016 ± 0·003^ac	2·89 ± 0·08^c	0·9 ± 0·13^c	0·348 ± 0·078^b	1·036 ± 0·502^c
M. brownii	Complete	Every 2nd day	0·018 ± 0·004^ac	2·44 ± 0·10^c	0·51 ± 0·09^d	0·115 ± 0·006^c	0·173 ± 0·047^d

Relative growth rate (whole-plant excluding aquatic roots; RGR), chlorophyll a concentration (chla), aquatic root dry mass (DM) of total removed and grown (mass at final harvest plus removed mass) are shown for the 28-d treatment period. To allow for comparisons within the table, the mass of aquatic roots was not included within the RGR. When aquatic root masses were included in the RGR of the controls (no aquatic root removal) whole-plant RGR did not differ significantly (P < 0·05) from those in expt 1 (Table 4). Data presented are means ± s.e., n = 3. Different letters indicate significant differences at P < 0·05 (comparisons down columns, within species).

n.a.: not applicable (these plants had no aquatic roots removed).

* Sediment roots included, aquatic roots removed from calculation.