Biopesticide Impact on Crops Using Extracts from Marigold Plants
Natural science news
2024.07.19
Botanicals from plants such as marigold, chrysanthemum, basil, and rosemary are increasingly being studied as potential replacements for chemical pesticides due to their effectiveness and environmental safety. A recent study conducted by PES University focused on the bioactive components found in Tagetes erecta and Tagetes patula, commonly known as marigolds, which have shown promising biocidal properties against two major crop pests, Spodoptera litura and Corcyra cephalonica.
In this study, researchers extracted crude compounds from different parts of T. erecta and T. patula using the Soxhlet extraction method. The leaf extracts were then analyzed using Gas Chromatography-Mass Spectrometry (GC-MS) to identify their components and confirm the presence of thiophenes, compounds known for their broad-spectrum biocidal properties. The study aimed to evaluate the larvicidal effects of these extracts on S. litura and C. cephalonica larvae through both direct and indirect application methods.
The indirect method involved coating castor leaves with various concentrations of methanolic extracts and allowing S. litura larvae to feed on them. In the direct method, larvae of both pest species were sprayed with different concentrations of the crude extracts. The results were significant: within 24 to 48 hours, there was a marked decrease in larval activity and survival rates. Specifically, 25 µl of T. erecta root and stem extracts achieved 100% larval mortality within 24 hours, whereas 50 µl of T. patula flower, root, and stem extracts killed 50% of the larvae in 48 hours. Additionally, a mini nursery evaluation showed that direct spraying of 25 µl of T. erecta leaf and flower extracts, as well as T. patula flower extract, resulted in 100% larval mortality within 24 hours on jowar saplings.
Botanicals from plants such as marigold, chrysanthemum, basil, and rosemary are increasingly being studied as potential replacements for chemical pesticides due to their effectiveness and environmental safety. A recent study conducted by PES University focused on the bioactive components found in Tagetes erecta and Tagetes patula, commonly known as marigolds, which have shown promising biocidal properties against two major crop pests, Spodoptera litura and Corcyra cephalonica.
In this study, researchers extracted crude compounds from different parts of T. erecta and T. patula using the Soxhlet extraction method. The leaf extracts were then analyzed using Gas Chromatography-Mass Spectrometry (GC-MS) to identify their components and confirm the presence of thiophenes, compounds known for their broad-spectrum biocidal properties. The study aimed to evaluate the larvicidal effects of these extracts on S. litura and C. cephalonica larvae through both direct and indirect application methods.
The indirect method involved coating castor leaves with various concentrations of methanolic extracts and allowing S. litura larvae to feed on them. In the direct method, larvae of both pest species were sprayed with different concentrations of the crude extracts. The results were significant: within 24 to 48 hours, there was a marked decrease in larval activity and survival rates. Specifically, 25 µl of T. erecta root and stem extracts achieved 100% larval mortality within 24 hours, whereas 50 µl of T. patula flower, root, and stem extracts killed 50% of the larvae in 48 hours. Additionally, a mini nursery evaluation showed that direct spraying of 25 µl of T. erecta leaf and flower extracts, as well as T. patula flower extract, resulted in 100% larval mortality within 24 hours on jowar saplings.
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