Determination of Freezing Points of Seconder Buds in Vitis vinifera and Vitis labrusca

This study was carried out to determine ability of secondary buds winter freezing in two Vitis species viz. vinifera L. and labrusca In 2016 2017, one genotype V. were sampled at 3 different periods during dormant period. The one-year-old shoots obtained from vineyards the on 4th, 5th 6th nodes has been used for test. For test, DTA (Differantial Thermal Analyses) methods test started +4 oC temperature decreased terminated -30 oC. According results, highest lowest temperatures start belongs -16.48 -19.49 oC, respectively. genotype, these values -15.77 -20.99 short period exotherm occurred deep dormancy both species. As a result, points varied among as well years physiological status plants. Determining grapes, it is possible make better prediction injury.