Base Growth Temperatures, Germination Rates and Growth Response of Contemporary Spring Wheat (Triticum aestivum L.) Cultivars from the US Pacific Northwest

Abstract

In eastern Washington, spring wheat cultivars that germinate and grow fast at low temperatures will provide the crop with a competitive advantage over spring emerging weeds in commercial production fields compared to cultivars that germinate and grow more slowly. The objective of this research was to develop a protocol to identify spring wheat cultivars that would germinate and grow more quickly at low temperatures. A novel data analysis method was used to separate the germination process into three components: (1) base temperature, (2) time to initiation of germination, and (3) germination rate. Spring wheat cultivars Edwall, Vanna, Wawawai, Wampum, Express, and Spillman were assessed through a series of controlled temperature gradient plate experiments. Base temperatures were not different (P=0.1) across cultivars, and once germination was initiated, germination rates among varieties were uniform (P=0.5). However, significant (P<0.001) differences were detected among varieties for time to germination. A subsequent growth chamber experiment confirmed differences in emergence and growth rate among spring wheat cultivars.