| Abstract: | Abstract Four European (Vitis vinifera L.) winegrape cvs., ‘Semillon’, ‘Pinot Noir,’ ‘Chardonnay’, and ‘Cabernet Sauvignon’, and one American (Vitis aestivalis Michx.) winegrape cv. ‘Cynthiana’, were subjected to three temperature regimes in growth chambers set at 20/15°C, 30/ 25°C, or 40/35°C, for 16/8 hr day/night to determine the influence of temperatures on vine growth and development. In general, the best temperature for shoot and root growth 28 days after temperature treatments was 20/15°C for ‘Semillon’, ‘Cabernet Sauvignon’, and ‘Cynthiana’, and 30/25°C for ‘Pinot Noir’ and ‘Chardonnay’. Although 40/35°C reduced number of leaves, shoots, tendrils, and internodes, total leaf area (LA), and total shoot biomass of all the cultivars, the reduction was more pronounced in ‘Cynthiana’ than in the European cultivars. The average reduction in number of leaves at 40/35°C for the European cultivars was 47%, compared with 92% for ‘Cynthiana’. The two types of grapes adapted differently to high temperature. Shoot growth in the European cultivars continued under high temperature, whereas growth ceased in ‘Cynthiana’. Roots of ‘Cynthiana’, however, were less susceptible to the adverse effect of high temperatures than were the shoots. This study shows that the European cultivars were relatively more tolerant to high temperature than the American cultivar and they have a potential for production of wine in the climate of south central Kansas. |
