Safer Alternatives to Highly Toxic Pesticides in Cotton Cultivation

Mar 21
20:43

2024

David Yvon

David Yvon

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In the quest to protect cotton crops from the destructive bollworm, the agricultural sector is turning to safer pesticide alternatives. These innovative solutions aim to mitigate the damage caused by bollworm larvae to the reproductive organs of cotton plants, which can lead to significant losses in bud, flower, and boll yield, as well as increased instances of boll rot.

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The Shift to Less Toxic Pesticides

The Ministry of Agriculture has endorsed several less toxic pesticides as substitutes for more hazardous ones in the fight against bollworms. These include indoxacarb,Safer Alternatives to Highly Toxic Pesticides in Cotton Cultivation Articles emamectin benzoate, and lambda-cyhalothrin. Additionally, other alternatives such as 37.5% thiodicarb, 2.5% spinosad, 10% methoxyfenozide, 5% hexaflumuron, and 1% abamectin are undergoing further testing and demonstration. Among these, abamectin, lambda-cyhalothrin, and hexaflumuron have seen widespread application in production, while emamectin benzoate has been recently introduced. The use of indoxacarb, thiodicarb, spinosad, and methoxyfenozide is still limited, but their characteristics and application techniques are gaining attention.

Indoxacarb: A Neurotoxin Disruptor

Indoxacarb operates by blocking sodium channels in the insect nervous system, leading to poor coordination, paralysis, and eventually death in target pests. It enters parasites through contact and ingestion, causing them to cease feeding and thus protecting crops. Notably, indoxacarb does not exhibit cross-resistance with other insecticides. For controlling cotton bollworm, a solution of 15% indoxacarb suspensions or 30% indoxacarb water dispersible granules at 40 mg/liter is recommended during the peak of egg hatching.

Thiodicarb: An Enzyme Inhibitor

Thiodicarb acts by inhibiting the cholinesterase enzyme in insects, leading to their demise. This inhibition is reversible, meaning that if the insect does not succumb to the poison, the enzyme's function can be restored. It is important to note that thiodicarb should not be mixed with alkaline or strongly acidic pesticides, nor with zineb or mancozeb. A 37.5% thiodicarb suspension at 500-625 mg/liter is used to control bollworm.

Spinosad: A Biochemical Pesticide

Spinosad, a 2.5% product, is a low-toxicity biochemical pesticide with a one-day safety interval for harvest. It acts quickly, with effects visible on the same day after spraying, and has a short half-life, making it easily degradable and less harmful to natural enemies. It is primarily used to prevent and treat pests like the diamondback moth, beet armyworm, and thrips. For bollworm control, a solution of more than 2.5% spinosad at 25-35 mg/liter is sprayed.

Methoxyfenozide: A Molting Disruptor

Methoxyfenozide is a low-toxicity diacylhydrazine insecticide that induces premature molting in Lepidoptera larvae, preventing them from forming a new exoskeleton and leading to early cessation of feeding and death. The action is fast, with larvae stopping feeding within 4-16 hours after ingestion and showing symptoms of poisoning. A 10% methoxyfenozide solution at 320-600 mg/liter is used for bollworm control.

Combining Pesticides for Enhanced Effectiveness

Studies have examined the combined effects of abamectin with chlorpyrifos, hexaflumuron, and agricultural mineral spray oil (PSO) on bollworms. Abamectin showed the highest virulence, followed by hexaflumuron, while chlorpyrifos was the least virulent, and PSO had almost no activity against bollworm larvae. The mixtures "Abamectin + chlorpyrifos (1:100)", "abamectin + hexaflumuron (1:5)", and "Abamectin + PSO (1:165)" demonstrated synergistic effects, with the latter two mixtures showing significant synergy.

Conclusion

The adoption of these less toxic pesticides is a positive step towards sustainable agriculture, reducing the environmental impact and potential health risks associated with highly toxic pesticides. As the agricultural community continues to innovate, it is crucial to support research and development that leads to safer, more effective pest control methods.

For more detailed information on these pesticides and their application, visit the Ministry of Agriculture or consult the Pesticide Action Network.

Please note that the original source provided (cospcn.com) could not be verified for updated information or fact-checking, as it was not accessible at the time of writing.