Barley and wheat under controlled climatic conditions: A model experiment of vigour and variability

Two cereal varieties (Bonus spring barley and Drabant spring wheat) were cultivated in the Stockholm phytotron according to standard methods previously described. Bonus is more long-day adapted and more specialized than Drabant, both generatively and vegetatively. Drabant does not reach the maximal level of grain productivity found in Bonus. This variety, however, when compared to Drabant, is characterized by an evident “waste” of vegetative matter for each unit of grain weight produced. Drabant, although lower in maximal yield, shows a higher generative efficiency, especially at shortened day lengths and raised temperatures. Phene variability is rather similar in the two varieties, with some striking exceptions, however. Different degrees of variability are apparently built into the individual traits (phenes) of which the barley plant, or the wheat plant, is composed, reacting in specific ways to the different kinds of phytotron environment.