Combined application of native Trichoderma isolates possessing multiple functions for the control of Fusarium wilt disease in banana cv. Grand Naine

Abstract

Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc) is considered as a lethal disease of bananas worldwide. To manage the disease effectively, 20 rhizospheric and 43 endophytic Trichoderma isolates obtained from 12 different Foc resistant banana accessions were evaluated against Foc in vitro and in vivo. In vitro screening among Trichoderma isolates for their multiple functions (mycelial and spore germination inhibition, hydrogen cyanide, chitinolytic enzymes, non-volatile and volatile metabolites production) in suppressing Foc and promoting plant growth (IAA production and phosphate solubilisation) indicated that the multiple biocontrol actions were significantly higher in 6 isolates of rhizospheric Trichoderma and 10 isolates of endophytic Trichoderma compared to other isolates. The greenhouse evaluation of individual application of these rhizospheric and endophytic Trichoderma isolates against Fusarium wilt pathogen in cv. Grand Naine (AAA) indicated significant suppression of Fusarium wilt disease and increased plant growth characters as compared to Foc pathogen inoculated plants. However, none of these individual Trichoderma isolates recorded complete suppression of Fusarium wilt disease. Therefore, the greenhouse evaluation involving combination of rhizospheric Trichoderma sp. NRCB3 + endophytic Trichoderma asperellum Prr2 recorded 100% reduction of Fusarium wilt disease and increased plant growth parameters up to 250% when compared to individual isolates application and Foc alone-inoculated plants. Further, the field evaluation of this combination of Trichoderma isolates applied for three times: (1) at 15 days before planting, (2) second month after planting and (3) fourth month after planting resulting in significant reduction of Fusarium wilt disease and also increase in bunch weight as compared to untreated control plants. Therefore, these Trichoderma isolates may be used in combination for the effective suppression of Fusarium wilt disease in banana.

Keywords:

• banana
• endophytes
• Fusarium oxysporum f. sp. cubense
• multiple functions
• Trichoderma isolates

Highlights

1. Fusarium wilt disease is considered as a destructive disease in banana throughout the banana growing regions of the world.

2. Bio priming of banana cv. Grand Naine with Trichoderma sp. NRCB3 and T. asperellum Prr2 possessing multiple functions could result in the effective suppression of Fusarium wilt disease besides increasing the plant growth parameters significantly.

3. Identified that a minimum time gap of 15 days are required between bio priming and planting of banana for the effective management of invading Fusarium wilt pathogen.

4. This is the first report of achieving effective suppression of Fusarium wilt disease through bio priming of banana (cv. Grand Naine) with Trichoderma isolates.

Acknowledgement

We greatly acknowledge the Indian council of Agricultural Research, New Delhi, for providing financial help to carry out this research work and also Director, NRCB, for the research facilities provided to carry out the experiments. We are also grateful to N. Marimuthu, T4 NRCB, Tiruchirapalli, for his help in recording observation during the study.

Disclosure statement

No potential conflict of interest was reported by the authors.