Effects of agrotechnical factors on leaf deseases and yield of winter wheat in a long-term experiment

The effects of forecrops (maize, sunflower), fertilization, crop protection and genotypes were studied on leaf diseases (powdery mildew, leaf rust, helminthosporium) and on the yield of different winter wheat varieties in a polyfactorial long-term experiment on chernozem soil in the Hajdusag region of eastern Hungary in the dry cropycar 2002. The indicated moderate infection with leaf diseases (powdery mildew 1-17%, leaf rust 0-6%, helminthosporium 2-15%). The severity of leaf diseases was significantly affected by fertilization and fungicide treatments, but the effects of forecrops and genotypes were moderate. The 2002 growing season was dry for winter wheat (the water deficit was 2 16 mm, indicating a 50% water deficiency compared to the average rainfall), but relatively good yields were obtained because of the favourable water and nutrient husbandry of chernozem soil, The maximum yields varied between 5600 and 7000 kg (.) ha(-1) when maize was the forecrop and between 5600 and 6900 kg (.) ha(-1) after sunflower. The differences in yields between the low input and mid-tech crop protection models were moderate (350-600 kg (.) ha(-1)) depending on the treatments (fertilizer rates, variety and forecrops) because of the dry vegetation period, i.e. low infection levels of leaf diseases. The maximum yields for various genotypes were 7000 kg (.) ha(-1) for GK Othalom, 6900 kg (.) ha(-1) for Jubilejnaja 50 and 6400 kg (.) ha(-1) for Mv Magdalena.