Effects of black geotextile mulch and grass mulch on the microclimate, fruit quality and anthocyanin components of ‘Xinyu’ table grape

We analysed the effects of black geotextile inter-row mulch, grass mulch and clean tillage as a control on the microclimate, anthocyanin components and fruit quality of 'Xinyu' table grape in a semi-arid climate. Black geotextile inter-row mulch increased the air and soil temperatures, while grass mulch decreased these. Six types of anthocyanins were detected in the grapes. Around 50% of the total anthocyanins were malvidin based (38.60%–39.10%) and peonidin based (25.80%–31.10%), with malvidin-3-O-glucoside being the main pigment (38.75%–39.05%), followed by peonidin-3-O-glucoside (23.84%–28.68%). The soluble solid content, reducing sugar content and sugar-acid ratio for the black geotextile treatment group were 12.93%, 10.05% and 25.85% higher, respectively, than the control. By contrast, grapes in the grass mulch treatment group had a significantly lower soluble solid content than the control, with a 7.32% reduction being observed. Neither type of mulch had a large effect on the vitamin C content nor yield. However, both black geotextile inter-row mulch and grass mulch could regulate the orchard microclimate and increased the total anthocyanin content by 36.04% and 5.03%, respectively, compared with the control. These findings suggest that grass mulch is the preferable cultivation method in the Turpan area.