Abstract
Sweet basil (Ocimum basilicum), a highly valuable medicinal crop, is extremely susceptible to Meloidogyne incognita infestation, leading to severe losses in yield and chemo-pharmaceutical quality. Currently, chemical nematicides are the only effective option for the disease management. However, high toxicity to non-target organisms and adverse impact on soil health motivated the look for ecofriendly alternatives. Here, bioinoculants (Bacillus megatarium (“BM”), B. subtilis (“BS”)) were isolated from the rhizosphere of various medicinal and aromatic plants growing in Lucknow region, India. Their biocontrol effects were studied in O. basilicum plants that were invaded by M. incognita either in single or in consortium with Trichoderma harzianum (“TH”) and their efficiency compared to chemical nematicide (carbofuran) and a microbial reference strain (Pseudomonas fluorescens). The results show that all bioinoculants enhanced the growth and oil yield production and increased the nutrient content of O. basilicum by significantly reducing M. incognita infestation by 46 to 72%. Among the strains, a consortium of BM and TH was the most potent treatment. The efficiency of these bioinoculants was not restricted to sterile soil condition but remained high also in natural soil conditions, indicating that enriching soils with rhizospheric microbes can be an effective alternative to chemical nematicides.
Highlights
Nematode management strategies are long-sought goals of plant pathologists
The results obtained from the biochemical screening showed that the isolated bacteria were bestowed with different plant beneficial activities
Application of indigenous microbes isolated from agricultural soils in the Lucknow region (B. megaterium, B. subtilis, and T. harzianum) was found to reduce root knot nematode activity in the rhizosphere of O. basilicum and increase all the auxiliary plant growth parameters, directly impacting overall plant health and essential oil yield
Summary
Due to the unavailability and high cost of efficient biological nematicides, farmers in developing countries such as in India often use synthetic chemical nematicides [1,2,3]. Wide use of chemical nematicides impacts non-target organisms and is hazardous to the environment [1]. Long-term use of such chemical nematicides alters the soil microbial flora and impacts soil health, resulting in declining productivity. Ocimum basilicum (CIM Soumya), commonly known as sweet basil, is a potent therapeutic plant which bears large variety of medicinal and aromatic compounds [4,5]. Because of its high economic value and industrial importance, sweet basil has been introduced as a commercial crop in many countries, including India [13]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
