The Biocontrol Potential of Endophytic Trichoderma Fungi Isolated from Hungarian Grapevines. Part I. Isolation, Identification and In Vitro Studies

This paper reports on the identification and in vitro characterization of several Trichoderma strains isolated from the Tokaj Wine Region in North-East Hungary. Ten isolates were analyzed and found to consist of six individual species—T. gamsii, T. orientale, T. simmonsii, T. afroharzianum, T. atrobrunneum and T. harzianum sensu stricto. The growth potential of the strains was assessed at a range of temperatures. We also report here on the in vitro biocontrol properties and fungicide tolerance of the most promising strains.

Sensitivity of field populations of Ascochyta rabiei to chlorothalonil, mancozeb and pyraclostrobin fungicides and effect of strobilurin fungicides on the progress of ascochyta blight of chickpea

Chickpea production faces a major challenge from ascochyta blight (Ascochyta rabiei), a devastating disease that can cause total crop loss. To assess the effect of repeated fungicide application on disease progress, strobilurin fungicides, primarily alternating pyraclostrobin and azoxystrobin treatments, were applied up to five times per year in each of 2 yr. A single application or two early applications reduced blight severity. A third application resulted in additional benefits in 1 of 2 yr, but additional applications did not reduce severity further. To monitor for fungicide tolerance in populations of A. rabiei, 66 single- spore isolates were collected and grown on growth media amended with chlorothalonil, mancozeb, or pyraclostrobin. Insensitivity to one or more of the fungicides was detected in 49 (74%) of the isolates. Based on the effect on conidial germination, insensitivity to pyraclostrobin or chlorothalonil was observed in 26 of 37 isolates (70%). Repeated fungicide application may be selecting for insensitive isolates of the pathogen; fungicide application should be combined with cultural measures to control ascochyta blight. Key words: Fungicide insensitivity, Ascochyta rabiei