1. Temperatures and net energy gain in a growing, mature head of lettuce
- Author
-
Werner J. Lipton
- Subjects
Net energy gain ,biology ,Lactuca ,biology.organism_classification ,Horticulture ,Thermocouple ,Solar gain ,Botany ,General Earth and Planetary Sciences ,Head (vessel) ,Mean radiant temperature ,General Environmental Science ,Mathematics ,Entire head - Abstract
A method was developed to determine the net heat gain per unit of time (G) in a mature, growing head of lettuce (Lactuca sativa L., var. capitata from measured temperatures, by adapting a formula used to calculate internal energy changes in columns of air, water, or soil ( Sellers , 1965). G also was calculated for hypothetical cubes (sides 1 cm), one of which represented the cool side of the head, and the other the warm side, and each having a thermocouple at its center. The mean for the two cubes differs from that for the entire head by less than 10%, and avoids the cumbersome determination of the mean temperature of the head. Tipburn of lettuce was discussed in relation to internal differences in G.
- Published
- 1971
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