Winter garlic rust (Puccinia spp.) rate under organic and conventional production conditions

Abstract

Due to low requirements for fertilizers and pesticides, garlic is a valuable crop in organic systems, although production may be hampered by diverse pathogens. In recent years, garlic rust (Puccinia spp.) has been increasingly present in our agro-ecological climate, developing into a significant problem for garlic production. The aim of the study was twofold: i) to monitor winter garlic rust rate in organic and in conventional production, and ii) to monitor genotype sensitivity to the pathogen in both production systems. Trials were conducted in 2012/2013 in Backi Petrovac, Serbia at the Institute of Field and Vegetable Crops in Novi Sad, and included 30 genotypes planted in organic and conventional field, simultaneously. Disease severity was evaluated visually, using a scoring system between zero and five. Overall average infection intensity score in conventional plots was 1.18, and in organic plots 0.79. There was no statistically significant difference between infection intensity in conventional versus organic plots. Nevertheless, reactions of certain genotypes to the causal agents of rust differed across organic and conventional plots ranging from no apparent infection symptoms in organic to severe symptoms in conventional plots.