Efficacy of Trichoderma spp as Biocontrol Agents against Rice Brown Spot Disease and Biochemical Approaches

Kalboush, Zeinab A.; Hassan, A. A.; Saleh, Mona M.

doi:10.21608/jppp.2017.46961

Efficacy of Trichoderma spp as Biocontrol Agents against Rice Brown Spot Disease and Biochemical Approaches

Document Type : Original Article

Authors

Rice Pathol.Dept., Plant Pathol. Res. Inst., Agric. Res. Center, Egypt.

10.21608/jppp.2017.46961

Abstract

Fourteen isolates of Trichoderma spp were tested for their efficacy in controlling Bipolaris oryzae pathogen of rice brown spot disease in vitro and in vivo. Isolates of T. hamatum 4, T. viride 1, T. harzianum 1, 2 and 3 and T. virens were the best, recording 100% inhibition of the pathogen radial growth. Treatments of soil, and foliar spray with culture filterates of these antagonistic isolates were undertaken in the greenhouse and field during 2015 and 2016 seasons. A reduction in disease severity as well as an increment in chlorophyll content, POX, PPO and PAL enzymes activity and total phenol content were observed. T. viride1 and T. koningii were able to produce Indole Acetic Acid (IAA) with concentrations of 8.281, 1.359 ppm, gibberellic acid (GA₃) 70.176, 41.052 ppm and abscisic acid (ABA) 1.649, 0.45 ppm, respectively. Foliar application of the cultural filtrates of T. harzianum 1 and T. viride 1 gave the highest concentration of IAA (20.697 and 11.916 ppm, respectively) in rice seedlings. Under field conditions, soil treatments with T. viride1 were more effective in reducing both brown spot percentage and disease severity similar to the effect of Del cup (Copper Sulfate Pentahydrate) fungicide in the two seasons.