Call Prefix : PR-T

Call Suffix : 2011

Call Cutter : T - Hort 17

Location : SEARCA Library

Format : TD

Publisher : University of the Philippines Los Banos,

Publication Date : April 2011

Publication Place : Philippines :

Summary : Romaine lettuce (Lactuca sativa L. cv. Romaine) were grown in containers under portable quonset protective structures during the period from July 29 to August 20, 2010, coinciding with the wet season period in the Philippines. Supplementary light using warmwhite (emitted a red-yellowish tone mostly in the 600-650 nm region), cool white (emitted a bluish tone in the 400-450 nm region), and a combination of warmwhite and cool white compact flourescent lamps (CFLs) were used to investigate the effects of light quality on plant growth, biomass accumulation, chlorophyll and carotenoid concentration and marketable yield. Each treatment was further subjected to three light duration namely three, six, and 12 hours. There was a significant effect of treatment using warmwhite CFL on fresh and oven dry weights. This was consequently translated into a significantly high marketable yield. Carotenoid concentration also increased with the use of supplementary light as compared to the control but not the chlorophyll level. Futhermore, plants exposed to longer supplementary light duration showed better development and amount of carbon fixed compared to those that received shorter duration or none at all. Results of the experiment showed that supplementary lighting satisfactorily compensated the limited solar radiation during the wet season production of lettuce under protective cultivation.