INFLUENCE OF SIMULATED SPRING FROST ON GROWTH AND YIELD OF THREE BARLEY CULTIVARS

Abstract

Three spring barley (Hordeum vulgare L.) cultivars were planted at four seeding dates to evaluate the effect of a simulated frost at the two-leaf stage on growth and yield. A portable field freezing chamber was used to subject the plants to a − 5.6 °C stress. The frost caused 49, 64 and 68% injury to the leaves and delayed heading by 2.4, 1.4 and 2.4 days in Gait, Atlas and Olli, respectively. Frost also reduced the number of tillers per plant, ripe heads per plant and plants per plot in all cultivars. Although the late-maturing cultivar Galt had the most leaf frost resistance, the average 13.8% yield reduction within all three cultivars, owing to the freezing stress, was not significantly different between any of the cultivars. Complete defoliation by clipping resulted in no further reduction in yield than that which occurred from partial defoliation by freezing. Delayed seeding resulted in an 8.6% reduction in yield. Frost reduced the yield of early seeded cultivars by 9.8% and late-seeded cultivars by 17.1%.