Figure 4.
Effect of grapevine leafroll disease on gas exchange parameters in Vitis vinifera cv. Pinot noir on rootstock 5BB. Transpiration rate is expressed as mmol H2O m−2 s−1, net photosynthesis (AN) as µmol CO2 m−2 s−1. Measurements were recorded on six different days over three seasons. Means were denoted by different letters (a, b, and c) when they differ significantly at p < 0.05 using Ducan’s new multiple range test. N = 8 per treatment and date. Healthy: symptomless; GLD_S+: grapevine leafroll disease causing mild symptoms; GLD_S++: grapevine leafroll disease causing severe symptoms.