Growth, development, and quality of red globe grapes using root-zone soil heating in a plastic greenhouse

Abstract

To study the effect of root-zone soil heating on growth, the fruit quality phenological phase, and berry quality of red globe grapes Vitis vinifera ‘Red Globe’ and on soil temperature in a plastic greenhouse, five-year-old red globe grapes were evaluated. The root-zone was heated during the early period of protected cultivation. Treatments were temperatures of (25 ±1)℃/(15 ±1)℃ (day/night) (T25), (20 ± 1)℃/(15 ± 1)℃(day/night) (T20), and nature root-zone soil temperature as control (ck). Results showed that compared to the control, the average temperature of T25 and T20 treatment were increase by about 13.1℃ and 8.4℃ during the heating period, and the T25 treatment advanced bud burst 26 d, flowering period 27 d, and maturity 18 d; whereas, the T20 treatment advanced bud burst 20 d, flowering period 21 d, and maturity 10 d. Through adoption of LSD for variance analysis, P=0.05, the shoot length and coarseness, cluster weight, ear number per plant, and yield per plant were greater than the control. Also, compared to the control, grapes with root-zone heating conditions showed a higher concentration of total soluble solids and vitamin C content and lower titratable acidity in its juice meaning better berry quality. Thus, appropriate increases in soil temperature could allow this grape ecotype an earlier break in dormancy, an earlier advance into the bud stage, and therefore an earlier arrival at the market.[Ch, 3 fig. 5 tab. 13 ref.]