The effects of bud load and different training systems on yield, quality and canopy climate characteristics of organically grown table grape varieties

In this study, the effects of different training systems and bud load levels on canopy microclimate, grape yield, quality properties, vegetative growth, flavonoids and anthocyanins of organically grown Early Cardinal and Trakya İlkeren grape varieties were investigated for three years. In all of the bud load levels, 20 buds were left for the first 500 g pruning weight and for each additional 500 g pruning weight 10 more buds left for control; 5 more buds left for first bud load and 15 more buds left for second bud load. Temperature and humidity value recorded within the canopy was not much different as regards training system and bud load treatments. External canopy of temperature value was determined to be higher than that of within canopy. However, humidity values obtained within canopy were found to be higher than external the canopy. Light intensity obtained from vines of Y training system was high. Phenological stages on vines of Y training system were observed to be earlier according to the vines of T training method. Considering grape yield, cluster weight and length, berry weight and length and bud fruitfulness, values from vines of Y training system were higher than that of T training system. The highest yield was recorded in the second bud load treatments for both of the varieties. Antioxidant activity level was found higher in grapes taken from Y training shape for both of the varieties. The average leaf area was higher for the vines trained with Y shape. The concentrations of myricetin and quercetin were confirmed significantly higher in the T training system. Y training system increased to the concentrations of anthocyanin for both cultivars. Content of peonidin-3- glucoside and delphinidin-3-glucoside in the control bud load and the concentrations of malvidin-3-glucoside, cyanidin-3-glucoside and petunidin-3-glucoside was determined higher in second bud loads for Early Cardinal. The amount of the pruning weight on the vines of first bud load was higher. Taking into consideration the findings regarding the properties mentioned above, Y training system and second bud load level was found appropriate to recommend for both cultivars. The values obtained from these applications also gave clues to the possibility of organic grapevine cultivation under trial site conditions.