Cover crop evapotranspiration in a northeastern US Concord (Vitis labruscana) vineyard

Background and Aims:  Although cover crops are largely used in vineyards, limited information is available on the amount of water they use. The aim of this study was to quantify cover crop evapotranspiration (ETcc) in the inter-row of a Concord (Vitis labruscana Bailey) vineyard. In addition, the hypothesis that ETcc could be accurately estimated through a relationship with incident solar radiation and reference crop evapotranspiration was tested. Methods and Results: ETcc was measured using mini-lysimeters located across the inter-row of single curtain- and Geneva double curtain-trained vines. Over the course of the study, the ETcc ranged between 0.6 and 2.6 mm/day. ETcc was linearly correlated with a reference crop evapotranspiration adjusted for the solar radiation incident on the vineyard cover crop (r2 = 0.81) in both single curtain and Geneva double curtain. Conclusions:  Our results indicate that ETcc under different vineyard canopies is mainly explained by the difference in solar radiation transmitted to the cover crop. Significance of the Study:  This study provides new insights on the possibility to estimate ETcc in a vineyard. A more complete energy balance study is needed to test our hypothesis under different environmental conditions.