Published online by Cambridge University Press: 27 March 2009
The potential of selected cultivar mixtures to decrease lodging and consequently improve yields in winter barley was examined in field experiments at two locations over 2 years. The experiments were designed to identify growing conditions and varietal characteristics associated with mixture effects, i.e. the deviations from arithmetic pure cultivar means, and to compare the latter with effects of growth regulators. Pathogens were controlled chemically.
Use of mixtures tended to reduce initial lodging. With increasing lodging, desired mixture effects prevailed in mixtures of cultivars highly susceptible with those highly resistant to lodging. On average, the yield advantage of mixtures compared with pure stands was small; it was greater when lodging decreased yield of a pure cultivar. Reductions in lodging prevailed in two-component mixtures; adding more components was of no advantage.
When lodging developed steadily, effects of mixtures on grain yields were comparable to those of growth regulators. When lodging was caused suddenly by a thunderstorm, only growth regulator applications resulted in yield improvements. Growth regulators resulted in yield advantages in two of the four trials only.