Plant, Food and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, B2N 5E3, Canada - Department of Biology, Acadia University, Wolfville, Nova Scotia, B4P 2R6, Canada
Joel F. Swift
Department of Biology, Saint Louis University, St. Louis, MO, 63103, USA
Zachary Helget
Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
Laura L. Klein
Department of Biology, Saint Louis University, St. Louis, MO, 63103, USA
Anh Ly
Department of Natural and Applied Sciences, Missouri State University, Springfield, MO, 65897, USA
Matthew Maimaitiyiming
Division of Food Sciences, University of Missouri, Columbia, MO, 65211, USA
Karoline Woodhouse
Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
Anne Fennell
Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
Misha Kwasniewski
Division of Food Sciences, University of Missouri, Columbia, MO, 65211, USA - Department of Food Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
Allison J. Miller
Department of Biology, Saint Louis University, St. Louis, MO, 63103, USA
Daniel H. Chitwood
Department of Horticulture, Michigan State University, East Lansing, MI 48823 USA - Department of Computational Mathematics, Science & Engineering, Michigan State University, East Lansing, MI, 48823, USA
Grapevine leaves have diverse shapes and sizes which are influenced by many factors including genetics, vine phytosanitary status, environment, leaf and vine age, and node position on the shoot. To determine the relationship between grapevine leaf shape or size and leaf canopy temperature, we examined five seedling populations grown in a vineyard in California, USA. The populations had one parent with compound leaves of the Vitis piasezkii type and a different second parent with non-compound leaves. In previous work, we had measured the shape and size of the leaves collected from these populations using 21 homologous landmarks. Here, we paired these morphological data with canopy temperature measurements made using a handheld infrared thermometer. After recording time of sampling and canopy temperature, we used a linear model between time of sampling and canopy temperature to estimate temperature residuals. Based on these residuals, we determined if the canopy temperature of each vine was cooler or warmer than expected, based on the time of sampling. We established a relationship between leaf size and canopy temperature: vines with larger leaves were cooler than expected. By contrast, leaf shape was not strongly correlated with variation in canopy temperature. Ultimately, these findings indicate that vines with larger leaves may contribute to the reduction of overall canopy temperature; however, further work is needed to determine whether this is due to variation in leaf size, differences in the openness of the canopy or other related traits.
