مرکز منطقه ای اطلاع رساني علوم و فناوري - Changes in soil mycobiota in response to previous crop and organic fertilizer applications in organic tomato cultivation

Abstract :

This study was conducted to determine the effects of the previous crop and organic fertilizer applications prior to tomato production on changes in soil fungal communities between 2011 and 2014. Field experiments were established according to Split Plots in Randomized Complete Block Design (RCBD) with three replications. In the study, three previous crop treatments from Alliaceae, Cruciferae, Fabaceae+Gramineae families (leek, broccoli and vetch+barley mixture) and control (no previous crop during winter season) were placed in the main plots whereas three different fertilizer sources (compost, organic commercial fertilizer-1 and organic commercial fertilizer-2) were placed in the sub-plots. It was determined that fungal microorganism species and their numbers determined in the soil samples taken after tomato harvest following each previous crop and fertilizer applications were different from the initial fungal microorganism profile and number. The numbers of isolates belonging to Penicillium and Aspergillus genera in tomato-grown soils after the previous crop and organic fertilizer applications decreased when compared with the number of initial isolates at the beginning of the experiment. F. oxysporum was found as the most prevalent species in Fusarium genus. While damping-off pathogens, Pythium and Rhizoctonia, and antagonist Acremonium were not observed in the beginning and 2012, they were detected in 2013 and 2014 years. Antagonist and pathogenic microbial community increased, compared to pre-sowing season. It was thought that the previous crop and organic fertilization applications created favorable conditions for the development of Trichoderma and other antagonistic organisms in tomato-grown plots. It can be useful to conduct more detailed studies on the impacts of soil mycobiota on plant diseases.