Effects of different sowing times on leaf scald and yield components of spring barley under dryland conditions

The effect of sowing date on severity of scald and yield components of barley was studied over 2 years, using 15-day intervals between sowing dates under dryland conditions in Turkey. Disease severity was greatest at the first sowing time, and it decreased linearly at subsequent sowing times in both years. Disease did not develop on flag and second leaves for the third sowing date, and was not observed on any leaf after the fourth and fifth dates of sowing in 2000 and 2001, respectively. After the third sowing date, a decrease in total grain yield and yield components, number of ears per plant, grains per head, and plant height was observed in both infected and control plots. Yield was also reduced by scald and resulted in total grain yield reductions of 10.1% and 6.0% for the first and second sowing dates in 2000, and 16.2%, 9.2%, and 3.0% on the first 3 sowing dates in 2001, respectively. At the first 2 sowing dates only ears per plant was decreased by scald, with respective reductions of 8.3% and 4.4% in 2000, and 14.3% and 8.5% in 2001, when compared with the control plots.