Frost Tolerance in Triticale and Other Winter Cereals at Flowering

Abstract

Spring radiation frost is of significant importance in Australia causing large yield and revenue losses to the national economy. Winter cereals are most susceptible to low temperatures during reproductive stage as reproductive parts are not protected by the leaf sheaths and ice can nucleate directly on them. Therefore, identification of winter cereals with reproductive frost tolerance is a priority for frost research in Australia. A series of experiments were conducted to evaluate relative reproductive frost tolerance in different commercial triticale genotypes and how they compared with other winter cereals, wheat and barley. Eight triticales (cv. Bogong, Tahara, H20, H151, H418, H426, JRCT 74 and JRCT 400), four bread wheats (cv. Kite, Ventura, Young and Wyalkatchem), one durum wheat (cv. Bellaroi) and one barley (cv. Kaputar) were tested over 2 years (2009 and 2010). In addition, the roles of cold hardening and potassium fertilization in frost tolerance were also investigated by using triticale variety H426. The plants were grown in a glasshouse and treated to a single overnight natural frost event at flowering (±5 days). The damage was assessed by counting the number of fertile grains at maturity. The collated results of two years showed a difference in frost tolerance between the different triticale varieties. However, the difference was not huge and varietal responses were mainly determined by frost temperature. Temperatures particularly below -3.90°C were found to be destructive in the current experiments.