%0 Journal Article
%T Effects of Elevated Temperature and Potassium on Biomass and Quality of Dark Red ¡®Lollo Rosso¡¯ Lettuce
%A Carl E. Sams
%A T. Casey Barickman
%A William L. Sublett
%J Horticulturae | An Open Access Journal from MDPI
%D 2018
%R https://doi.org/10.3390/horticulturae4020011
%X Abstract Lettuce is an economically important crop for small and medium-sized growers. When grown in adverse environmental conditions, lettuce is vulnerable to a deterioration of yield and quality. Research concerning the impact of elevated potassium (K) levels on leafy vegetables, such as lettuce, is lacking. Therefore, seeds of dark-red ¡®Lollo¡¯ lettuce were germinated under greenhouse conditions at 25/20 ¡ãC (day/night). Plants were transferred into 11-L containers and placed into growth chambers at 25 and 33 ¡ãC. Plants were grown with K treatments of 117.3 (control), 234.6 (2¡Á), 469.2 (4¡Á), and 4) 938.4 (8¡Á) mg¡¤L £¿1. Increasing K treatments resulted in a negative quadratic response on lettuce dry mass and generated 14% more leaf calcium at 234.6 mg¡¤L £¿1. An increase in temperature from 25 to 33 ¡ãC increased leaf dry matter and biomass by 40% and 43%, respectively. Leaf water content increased by 3% as temperature increased. Plants grown at 33 ¡ãC had greater quercetin glycosides compared to plants grown at 25 ¡ãC. The results from this study suggest that temperature is a stronger regulatory factor than increasing K in the determination of lettuce yield and quality. Increasing K concentration to 234.6 mg¡¤L £¿1 results in greater concentrations of leaf minerals without compromising plant yield. View Full-Tex
%K red lettuce
%K hydroponics
%K flavonoids
%K heat stress
%K growth chambers
%K phenolic acids
%K mineral nutrients
%U https://www.mdpi.com/2311-7524/4/2/11