Title of the dataset:
Data underlying the publication: Plant Factories Are Heating Up: Hunting for the Best Combination of Light Intensity, Air Temperature and Root-Zone Temperature in Lettuce Production

Creators:
Esther Meinen(1), Laura Carotti(2) 0000-0003-0022-0057, Luuk Graamans(1) 0000-0003-2841-1357, Federico Puksic(1), Michele Butturini(1) 0000-0001-5618-9736, Cecilia Stanghellini(1) 0000-0003-2281-8711
(1) Wageningen University and Research, Wageningen, Netherlands
(2) University of Bologna, Bologna, Italy



Contributors:


Related publication:
Plant Factories Are Heating Up: Hunting for the Best Combination of Light Intensity, Air Temperature and Root-Zone Temperature in Lettuce Production
https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.592171/full

Description:
This study analyzed interactions among photon flux density (PPFD), air temperature, root-zone temperature for growth of lettuce with non-limiting water, nutrient, and CO2 concentration. We measured growth parameters in 48 combinations of a PPFD of 200, 400, and 750 μmol m–2 s–1 (16 h daylength), with air and root-zone temperatures of 20, 24, 28, and 32°C. Lettuce (Lactuca sativa cv. Batavia Othilie) was grown for four cycles (29 days after transplanting). Eight combinations with low root-zone (20 and 24°C), high air temperature (28 and 32°C) and high PPFD (400 and 750 μmol m–2 s–1) resulted in an excessive incidence of tip-burn and were not included in further analysis. Dry mass increased with increasing photon flux to a PPFD of 750 μmol m–2 s–1. 
The effect of air temperature on fresh yield was linked to all leaf expansion processes. SLA, shoot mass allocation and water content of leaves showed the same trend for air temperature with a maximum around 24°C. The effect of root temperature was less prominent with an optimum around 28°C in nearly all conditions. With this combination of temperatures, market size (fresh weight shoot = 250 g) was achieved in 26, 20, and 18 days, at 200, 400, and 750 μmol m–2 s–1, respectively, with a corresponding shoot dry matter content of 2.6, 3.8, and 4.2%. In conclusion, three factors determine the “optimal” PPFD: capital and operational costs of light intensity vs the value of reducing cropping time, and the market value of higher dry matter contents.

Keywords:
Lettuce, vertical farms, light use efficiency, lettuce growth 

Spatial coverage:
Two climate rooms in Wageningen

Temporal coverage:
2018-2019

This dataset contains the following files:
original_data_set_lettuce.xlsx

Explanation of variables:
see separate sheet in file

Methods, materials and software:
see section Materials and Methods of the paper: https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.592171/full


This dataset is published under the CC BY (Attribution) license.
This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator.

