Data from: Does green stem photosynthesis affect plant drought tolerance and recovery in avocado?

<div> <p>Data and associated analysis code for Valverdi et al. (2025) Does green stem photosynthesis affect plant drought tolerance and recovery in avocado? Published in <em>AoB Plants</em></p> <p>Two data files and one code script for analysis are included: </p> <p><strong>Valverdietal-AvocadoStemPhotosynthesisDrought-MetaData-4Aug25.csv</strong><strong><em> </em></strong>-Provides metadata (header, description, units, measurement type) for each column of the file entitled<strong> </strong><em>"Valverdietal-AvocadoStemPhotosynthesisDrought-Data-4Aug25.csv"</em></p> <p><strong>Valverdietal-AvocadoStemPhotosynthesisDrought-Data-4Aug25.csv</strong><em><strong> </strong>- </em>Provides raw data for field and lab observations of plant functional traits as described in the methods section of this data record. </p> <p><strong>Valverdietal-AvocadoStemPhotosynthesisDrought-Ranalysis-4Aug25.R</strong> <em>- </em>Provides the R code used to generate the statistical analysis and figures in the study using the data file entitled <em>"Valverdietal-AvocadoStemPhotosynthesisDrought-Data-4Aug25.csv"</em></p> <p>Contact Gregory R. Goldsmith (goldsmith at chapman dot edu) for additional information. </p> </div><p>Abstract:</p><p>Woody plants with green stems may have advantages over non-green-stemmed plants in that extra photosynthetic carbon gain has the potential to improve plant drought tolerance and aid drought recovery. However, most studies relating to green stem photosynthesis and drought tolerance have been conducted on non-horticultural plants under natural growing conditions. We investigated whether avocado green stem photosynthesis enhances drought tolerance and recovery. We applied light exclusion and drought treatments to three-year-old potted trees of cultivars 'Hass' and 'Fuerte.' Measurements of soil moisture, midday stem water potential, stem photosynthesis, bark chlorophyll concentration, concentration of sugars + starch and stem hydraulic conductivity were conducted before, during, and three weeks after rewatering. Green stems of avocado re-assimilate CO₂, but values did not significantly differ between cultivars. We also found that light exclusion reduced stem photosynthesis by 65% in ‘Fuerte’ and 30% in ‘Hass’ although bark chlorophyll concentration was unchanged. Drought reduced stem photosynthesis by 60%. Following drought recovery, there were neither treatment, nor cultivar effects, on stem photosynthesis. We also observed no effect of light treatment on hydraulic conductivity, such that there is no clear effect of stem photosynthesis on drought tolerance of these avocado trees. However, we observed an increase in hydraulic conductivity during the drought period with an increase in the concentration of sugars in the sapwood and a decrease in the concentration of starch, suggesting osmotic adjustment. nulltheless, the contribution of carbon gain through stem photosynthesis may not play a significant role in hydraulic functioning of avocado under these conditions.</p>