Grain quality and yield of spring barley in field trials under variable growing conditions

Effects of the year, previous crop and control of leaf diseases on grain yield, test weight, protein and starch content, Fusarium head blight (FHB) and deoxynivalenol (DON) content in grain were investigated in four spring barley varieties. The trials were set up in 2001-2004 at Kroměříž (235 m above sea level, average annual temperature 8.7°C, annual precipitation sum 599 mm) in a five-course crop rotation, where spring barley followed the previous crops sugar beet, winter wheat, maize, and oilseed rape. The experimental years differed a lot in temperature and precipitation. The years 2001 and 2002 were dry and warm and grain yield was much lower as compared to that in the following years even though the other growing conditions were identical. The most stable quality parameters were obtained after the previous crop sugar beet. The average value of test weight was 661 g/l(ranging from 629 to 685 g/l), protein content 11.2% (10.3-11.7%) and starch content 61.5% (58.9-64.9%). Grain yield averaged 6.67 t/ha. Test weight after maize was on average 658 g/l(619-692 g/l), protein content 11.5% (10.1-12.4%), starch content 60.7% (59.2-63.8%), and grain yield 6.24 t/ha. Test weight and starch content were lower and protein content higher after oilseed rape and winter wheat. A higher FHB incidence and DON content were found after the previous crop maize. In 2001 and 2002 with strong water deficit during the growing seasons, more grains infected by Fusarium spp. were detected and DON content was higher too. The increase was due to a short rainy period at heading of spring barley. Problems of variable conditions for growing malting varieties of spring barley and current possibilities of producing both good grain yields and quality are discussed.