PT  - JOURNAL ARTICLE
AU  - Barbara J. Schnabel
AU  - Robert L. Wample
TI  - Dormancy and Cold Hardiness in <em>Vitis vinifera</em> L. cv. White Riesling as Influenced by Photoperiod and Temperature
AID  - 10.5344/ajev.1987.38.4.265
DP  - 1987 Jan 01
TA  - American Journal of Enology and Viticulture
PG  - 265--272
VI  - 38
IP  - 4
4099  - http://www.ajevonline.org/content/38/4/265.short
4100  - http://www.ajevonline.org/content/38/4/265.full
SO  - Am J Enol Vitic.1987 Jan 01; 38
AB  - Cold hardiness of Vitis vinifera L. cv. White Riesling was examined using controlled environments to establish the roles of photoperiod and temperature. Field-grown, potted plants were maintained for comparison. Gradually decreasing daylengths, when combined with constant warm temperatures, increased cane hardiness by 0.8°C, while primary bud hardiness was decreased by 2.7°C. Combining constant cool temperatures with gradually decreasing daylengths resulted in an increase in cane and primary bud hardiness of 1.3°C and 0.8°C, respectively. Long photoperiods and gradually decreasing temperatures increased cane and primary bud hardiness by 1.8°C and 1.1°C, respectively. Combining gradually decreasing temperatures and decreasing photoperiods was the most effective and caused increased hardiness of canes by 4.5°C and primary buds by 5.2°C, thus demonstrating a synergistic effect of these environmental factors. Depth of rest induced by these treatments was examined following cold hardiness evaluation. A chilling treatment facilitated the transition from dormancy to active growth.