Trichoderma harzianum: a biocontrol agent against Bipolaris oryzae

Abstract

Rice brown spot, caused by Bipolaris oryzae, can be a serious disease causing a considerable yield loss. Trichoderma harzianum is an effective biocontrol agent for a number of plant fungal diseases. Thus, this research was carried out to investigate the mechanisms of action by which T. harzianum antagonizes Bipolaris oryzae in vitro, and the efficacy of spray application of a spore suspension of T. harzianum for control of rice brown spot disease under field conditions. In vitro, the antagonistic behavior of T. harzianum resulted in the overgrowth of B. oryzae by T. harzianum, while the antifungal metabolites of T. harzianum completely prevented the linear growth of B. oryzae. Light and scanning electron microscope (SEM) observations showed no evidence that mycoparasitism contributed to the aggressive nature of the tested isolate of T. harzianum against B. oryzae. Under field conditions, spraying of a spore suspension of T. harzianum at 10(8)spore ml(-1) significantly reduced the disease severity (DS) and disease incidence (DI) on the plant leaves, and also significantly increased the grain yield, total grain carbohydrate, and protein, and led to a significant increase in the total photosynthetic pigments (chlorophyll a and b and carotenoids) in rice leaves.

Efficacy of Biocontrol Agents against Drechslera setariae Causing Leaf Spot of Pearl Millet

“…Mycelial growth (mm) Per cent growth inhibition Present finding has close concurrence with the finding of Hulagappa (2012) and Kumar et al, (2009) (Jha et al, 2004;Harish et al, 2007;Abdel-Fataah et al, 2007 andFranca et al, 2015). Trichoderma harzianum and Pseudomonas fluorescens were found effective against brown leaf spot disease of paddy caused by Drechslera oryzae (Rao et al, 2013).…”

Optimizing of Trichoderma viride Cultivation in Submerged State Fermentation

“…Trichoderma-Based Biocontrol Agents (BCAs) possess better ability to promote plant growth and soil remediation activity compared to their counterparts (virus, bacteria, nematodes and protozoa [3,4] . Their capability to synthesize antagonistic compounds (proteins, enzymes and antibiotics) and micro-nutrients (vitamins, hormones and minerals) enhance their biocontrol activity.…”

“…There is abundant literature on the use of conventional synthetic media like glucose, cellulose, soluble starch and molasses to produce Trichoderma spp. [5,6] . However, the cost of these raw materials for commercial production of BCAs is one of the major limitations behind the restricted use.…”

In Vitro Evaluation of Fungicides, Plant Extracts and Biocontrol Agents against Brown Leaf Spot of Paddy

“…While, the antifungal metabolites of T. harzianum completely prevented the linear growth of the pathogen (Abdel-Fattah et al, 2007). Keeping this in view, the present study was undertaken to evaluate the efficacy of fungicides, botanicals and biocontrol agents against brown spot of rice under laboratory conditions.…”