Bangladesh's agriculture is advancing with modern technology, improved seed and scientific farming, but some unplanned practices born of ignorance are becoming a major threat. One is "cocktail spraying": farmers mix several insecticides, fungicides, miticides, hormones and micronutrients into a new spray, believing that applying everything together will control every pest and disease at once. In reality, each chemical has its own properties and action, and mixing them can create new compounds through chemical reactions that harm plants or even destroy an entire crop.

The writer recalls DDT, whose discovery earned Swiss scientist Paul Hermann Müller the Nobel Prize in 1948 and which saved many lives in the Second World War, but which was later found to be seriously harmful and banned in most countries. Blind use of any chemical, the history shows, can have dire long-term consequences.

• **Imitation:** farmers copy neighbours who seem to get good, if temporary, results.
• **Poor diagnosis:** many farmers and pesticide sellers cannot identify the disease or pest, so they mix several products hoping something will work.
• **Sellers' influence:** some dishonest sellers recommend several products at once to boost sales.
• **Saving cost and time:** spraying labour is expensive, and in haor areas water must be carried from far away, so farmers want to do everything in one go.
• **Adulterated products:** when a single product fails because of poor quality, farmers feel forced to combine several.

Crops can suffer leaf scorch, stunted growth or total loss; costs rise without the expected results; soil fertility and beneficial insects suffer; pests and pathogens become resistant, requiring stronger doses; and toxic residues in food threaten public health. Signs that a mixture is reacting harmfully include the water heating up, bubbles or foam, a change in colour, or sediment settling at the bottom.

• Stop using unnecessary and unapproved mixtures.
• Consult agriculture officers or experts before applying pesticides, and identify the problem to choose a specific solution.
• Use tested, approved combination products available from companies.
• Train farmers regularly and raise awareness of scientific farming.
• Enforce strict government controls on adulterated and substandard pesticides.

Cocktail sprays may give short-term results but are a serious long-term threat, the writer concludes; farmers' knowledge, responsible sellers and effective policy together can build safe, sustainable agriculture.

Source: Jagonews24. First published in Bengali on The Agro News.