Nocturnal and diurnal grapevine transpiration – relationship with meteorological parameters

An experiment was carried out in a semi-arid area of Spain (Albacete) with the objective of quantifying the daily transpiration (nocturnal and diurnal) of grapevine ‘Tempranillo’ during 2012. Measurements of transpiration were taken in a weighing lysimeter; the soil surface was covered with a waterproof canvas to avoid the evaporative component of evapotranspiration. The sample frequency was 1 s, and a mean value was recorded with a datalogger (CR10X, Campbell Scientific) every 15 min, which allowed for measuring the transpiration every quarter of an hour. The results show values of night transpiration between 3 and 35%. With the objective of quantifying the effect of different meteorological parameters on transpiration, air temperature, relative humidity, wind velocity and solar radiation were measured with an automated weather station located over a reference grass surface less than 100 m from the vineyard lysimeter. The work shows the relationship between the different parameters measured.