Arpa ağbenek ( Pyrenophora teres Drechs.) hastalığının yayılış durumu, neden olduğu verim kaybı ve verim bileşenlerine etkisi üzerinde araştırmalar

Abstract

During 2008-2013, in surveys total 504 barley fields were inspected and 258 of them (51.2%) were found to be infected by net blotch ( Pyrenophora teres Drechs.) disease. The prevalence was highest level in Thracian region of Turkey as 80.2% and then, was 51.2% in Aegean, 44.4% in Blacksea, 41.4% in Mediterranean regions. In Middle Anatolia infected field percentage was found as 14.3, in Southern Marmara 12.9, however any infected field was not come across in South-Eastern region, in 48 fields inspected. Besides net type-net blotch in 258 fields, spot-type-net blotch was only observed in 6 fields of 258. With using different barley varieties and applying different chemicals, between 4.6-78.0%, 43 different levels of disease intensities were developed in Thrace in 2010-2013 trials. A negative, linear, significant correlation was determined between disease intensity with grain yield of ear and 1000-kernel weight and not any significant relationship with kernel count per ear. Net blotch caused grain yield loss, as average 23.25%, changing 19.27-30.55, according years, 1000 kernel weight loss, as average 16.99%, changing 7.21-21.17% and kernel count per ear loss, as average 6.67%, changing 2.11-13.34. So, it was concluded the mainly reason of yield loss was the lack of the seed size and seed weight per ear because of disease. It was seen to be possible the estimating of yield loss from the severity percent of net blotch. The disease caused loss, as about 51.7% of the percentage of disease severity detected on upper 3 leaves during milky stage.