In situ estimates of waterhyacinth leaf tissue nitrogen using a SPAD-502 chlorophyll meter

Authors: Dray, F Allen; Center, Ted; MATTISON, ELIZABETH - Student Conservation Association

Submitted to: Aquatic Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/2012
Publication Date: 4/6/2012
Citation: Dray Jr, F.A., Center, T.D., Mattison, E. 2012. In situ estimates of waterhyacinth leaf tissue nitrogen using a SPAD-502 chlorophyll meter. Aquatic Botany. DOI: 10.1016/j.aquabot.2012.03.005.

Interpretive Summary: The ability to quickly estimate leaf nitrogen in the aquatic weed waterhyacinth is important to studies investigating the efficacy of the biological control agents released against it. Traditional methods are slow, cumbersome, and require destruction of the plants being measured. We evaluated a hand-held chlorophyll meter for producing instantaneous estimates of waterhyacinth leaf nitrogen content in a manner that was non-destructive. The meter was efficient and effective, but must be recalibrated for each different experiment or habitat and the data are thus not suitable for comparison between studies.

Technical Abstract: An important component of plant quality as perceived by herbivores is leaf nitrogen content. Traditional methods for assessing leaf nitrogen are time-consuming and destructive, thus making them unsuitable for studies of in situ plant quality. We evaluated the suitability of using a hand-held chlorophyll meter to estimate waterhyacinth leaf nitrogen in support of ongoing studies investigating the relationship between waterhyacinth and its biological control agents, the weevils Neochetina bruchi and N. eichhorniae. The meter was efficient and effective, but must be recalibrated for each different experiment or habitat and the data are thus not suitable for comparison between studies.