Akademik Veri Yönetim Sistemi
INTERNATIONAL JOURNAL OF FRUIT SCIENCE, cilt.20, 2020 (SCI-Expanded)
The aim of this study was to confirm the hypothesis that pretest temperature changes could alter the cold hardiness of the grapevine dormant buds and eventually the result of differential thermal analysis (DTA) test. For this reason, dormant buds of 'Karaerik' grape cultivar were collected at different times and tested using different DTA procedures. Dormant buds taken at nine different sampling temperatures (8, 6, 5, 3, -1, -3, -4, -5, and -9 degrees C) were exposed to freezing test according to three DTA test approaches (TestA-A, TestA-4 and Test20-4, to represent ambient storage and ambient test, ambient storage and 4 degrees C test, and 20 +/- 2 degrees C storage and 4 degrees C test or standard DTA method, respectively) to verify our hypothesis in 2015-16 and 2016-17. The LTE (low temperature exotherm) temperatures were determined as the indicator of death of primary buds at grapevines' dormant buds, tested according to TestA-A approach, TestA-4 approach and Test20-4 approach (the standard methodology). It was found that temperature changes such as rapid cooling, warming and thawing in the TestA-4 approach, and warming-cooling and melting-cooling in the Test20-4 approach altered LTE values of dormant buds depending on the test start temperature. It was determined that the LTE values of dormant buds tested according to TestA-4 and Test20-4 approaches were higher than that of the ones tested with TestA-A approach. Compared to TestA-A approach, the LTE values of dormant buds were between 0.00 and 4.00 degrees C in the TestA-4 approach and 0.00 and 2.77 degrees C in the Test20-4 approach based on temperature changes. As a result, to achieve reliable, and consistent LTE results at DTA tests, it was determined that dormant buds should be brought into laboratory by keeping the temperatures at the sampling time, prepared for test at these temperatures and to start DTA test from these temperatures is a right approach.