Set-up, calibration and testing of an automated chamber system for gas exchanges measurement of field-grown whole-grapevine (Vitis x Vinifera 'Aglianico')

Many studies rely on chambers to cover the entire canopy and use portable photosynthesis systems for measuring gas exchanges such as net and gross CO2 assimilation and ecosystem respiration. An open-system plant-chamber (20 m(3) volume) was developed to allow CO2 and H2O exchange measurements of field-grown, trellised, grapevines (Vitis vinifera L. cv 'Aglianico'). A framed design allowed the chamber to withstand sustained winds, overcoming one typical disadvantage of the balloon-type chamber. Chamber was designed to minimize environmental effects, and to accommodate the trellis of three, mature field-grown vines. The open chamber system is essentially similar to a leaf chamber: outside air is continuously blown at known flow rate into the enclosure (plastic balloon) where gas exchanges occurs. The difference of both water vapour and CO2 concentration between the incoming and the exiting air, measured by infrared gas analysers, allows the estimation of transpiration and photosynthesis. Effect of time of the day, temperature and/or vapour pressure deficit (VPD) on whole-plant net CO2 exchange rate (NCER) of grapevine plants were studied.